# Source: https://huggingface.co/docs/transformers/v5.0.0rc1/model_doc/mask2former.md

# Mask2Former

## Overview

The Mask2Former model was proposed in [Masked-attention Mask Transformer for Universal Image Segmentation](https://huggingface.co/papers/2112.01527) by Bowen Cheng, Ishan Misra, Alexander G. Schwing, Alexander Kirillov, Rohit Girdhar. Mask2Former is a unified framework for panoptic, instance and semantic segmentation and features significant performance and efficiency improvements over [MaskFormer](maskformer).

The abstract from the paper is the following:

*Image segmentation groups pixels with different semantics, e.g., category or instance membership. Each choice
of semantics defines a task. While only the semantics of each task differ, current research focuses on designing specialized architectures for each task. We present Masked-attention Mask Transformer (Mask2Former), a new architecture capable of addressing any image segmentation task (panoptic, instance or semantic). Its key components include masked attention, which extracts localized features by constraining cross-attention within predicted mask regions. In addition to reducing the research effort by at least three times, it outperforms the best specialized architectures by a significant margin on four popular datasets. Most notably, Mask2Former sets a new state-of-the-art for panoptic segmentation (57.8 PQ on COCO), instance segmentation (50.1 AP on COCO) and semantic segmentation (57.7 mIoU on ADE20K).*

 Mask2Former architecture. Taken from the original paper. 

This model was contributed by [Shivalika Singh](https://huggingface.co/shivi) and [Alara Dirik](https://huggingface.co/adirik). The original code can be found [here](https://github.com/facebookresearch/Mask2Former).

## Usage tips

- Mask2Former uses the same preprocessing and postprocessing steps as [MaskFormer](maskformer). Use [Mask2FormerImageProcessor](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerImageProcessor) or [AutoImageProcessor](/docs/transformers/v5.0.0rc1/en/model_doc/auto#transformers.AutoImageProcessor) to prepare images and optional targets for the model.
- To get the final segmentation, depending on the task, you can call [post_process_semantic_segmentation()](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerImageProcessor.post_process_semantic_segmentation) or [post_process_instance_segmentation()](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerImageProcessor.post_process_instance_segmentation) or [post_process_panoptic_segmentation()](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerImageProcessor.post_process_panoptic_segmentation). All three tasks can be solved using [Mask2FormerForUniversalSegmentation](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerForUniversalSegmentation) output, panoptic segmentation accepts an optional `label_ids_to_fuse` argument to fuse instances of the target object/s (e.g. sky) together.

## Resources

A list of official Hugging Face and community (indicated by 🌎) resources to help you get started with Mask2Former.

- Demo notebooks regarding inference + fine-tuning Mask2Former on custom data can be found [here](https://github.com/NielsRogge/Transformers-Tutorials/tree/master/Mask2Former).
- Scripts for finetuning `Mask2Former` with [Trainer](/docs/transformers/v5.0.0rc1/en/main_classes/trainer#transformers.Trainer) or [Accelerate](https://huggingface.co/docs/accelerate/index) can be found [here](https://github.com/huggingface/transformers/tree/main/examples/pytorch/instance-segmentation).

If you're interested in submitting a resource to be included here, please feel free to open a Pull Request and we will review it.
The resource should ideally demonstrate something new instead of duplicating an existing resource.

## Mask2FormerConfig[[transformers.Mask2FormerConfig]]

#### transformers.Mask2FormerConfig[[transformers.Mask2FormerConfig]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/configuration_mask2former.py#L28)

This is the configuration class to store the configuration of a [Mask2FormerModel](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerModel). It is used to instantiate a
Mask2Former model according to the specified arguments, defining the model architecture. Instantiating a
configuration with the defaults will yield a similar configuration to that of the Mask2Former
[facebook/mask2former-swin-small-coco-instance](https://huggingface.co/facebook/mask2former-swin-small-coco-instance)
architecture.

Configuration objects inherit from [PreTrainedConfig](/docs/transformers/v5.0.0rc1/en/main_classes/configuration#transformers.PreTrainedConfig) and can be used to control the model outputs. Read the
documentation from [PreTrainedConfig](/docs/transformers/v5.0.0rc1/en/main_classes/configuration#transformers.PreTrainedConfig) for more information.

Currently, Mask2Former only supports the [Swin Transformer](swin) as backbone.

Examples:

```python
>>> from transformers import Mask2FormerConfig, Mask2FormerModel

>>> # Initializing a Mask2Former facebook/mask2former-swin-small-coco-instance configuration
>>> configuration = Mask2FormerConfig()

>>> # Initializing a model (with random weights) from the facebook/mask2former-swin-small-coco-instance style configuration
>>> model = Mask2FormerModel(configuration)

>>> # Accessing the model configuration
>>> configuration = model.config
```

**Parameters:**

backbone_config (`PreTrainedConfig` or `dict`, *optional*, defaults to `SwinConfig()`) : The configuration of the backbone model. If unset, the configuration corresponding to `swin-base-patch4-window12-384` will be used.

backbone (`str`, *optional*) : Name of backbone to use when `backbone_config` is `None`. If `use_pretrained_backbone` is `True`, this will load the corresponding pretrained weights from the timm or transformers library. If `use_pretrained_backbone` is `False`, this loads the backbone's config and uses that to initialize the backbone with random weights.

use_pretrained_backbone (`bool`, *optional*, `False`) : Whether to use pretrained weights for the backbone.

use_timm_backbone (`bool`, *optional*, `False`) : Whether to load `backbone` from the timm library. If `False`, the backbone is loaded from the transformers library.

backbone_kwargs (`dict`, *optional*) : Keyword arguments to be passed to AutoBackbone when loading from a checkpoint e.g. `{'out_indices': (0, 1, 2, 3)}`. Cannot be specified if `backbone_config` is set.

feature_size (`int`, *optional*, defaults to 256) : The features (channels) of the resulting feature maps.

mask_feature_size (`int`, *optional*, defaults to 256) : The masks' features size, this value will also be used to specify the Feature Pyramid Network features' size.

hidden_dim (`int`, *optional*, defaults to 256) : Dimensionality of the encoder layers.

encoder_feedforward_dim (`int`, *optional*, defaults to 1024) : Dimension of feedforward network for deformable detr encoder used as part of pixel decoder.

encoder_layers (`int`, *optional*, defaults to 6) : Number of layers in the deformable detr encoder used as part of pixel decoder.

decoder_layers (`int`, *optional*, defaults to 10) : Number of layers in the Transformer decoder.

num_attention_heads (`int`, *optional*, defaults to 8) : Number of attention heads for each attention layer.

dropout (`float`, *optional*, defaults to 0.1) : The dropout probability for all fully connected layers in the embeddings, encoder.

dim_feedforward (`int`, *optional*, defaults to 2048) : Feature dimension in feedforward network for transformer decoder.

pre_norm (`bool`, *optional*, defaults to `False`) : Whether to use pre-LayerNorm or not for transformer decoder.

enforce_input_projection (`bool`, *optional*, defaults to `False`) : Whether to add an input projection 1x1 convolution even if the input channels and hidden dim are identical in the Transformer decoder.

common_stride (`int`, *optional*, defaults to 4) : Parameter used for determining number of FPN levels used as part of pixel decoder.

ignore_value (`int`, *optional*, defaults to 255) : Category id to be ignored during training.

num_queries (`int`, *optional*, defaults to 100) : Number of queries for the decoder.

no_object_weight (`int`, *optional*, defaults to 0.1) : The weight to apply to the null (no object) class.

class_weight (`int`, *optional*, defaults to 2.0) : The weight for the cross entropy loss.

mask_weight (`int`, *optional*, defaults to 5.0) : The weight for the mask loss.

dice_weight (`int`, *optional*, defaults to 5.0) : The weight for the dice loss.

train_num_points (`str` or `function`, *optional*, defaults to 12544) : Number of points used for sampling during loss calculation.

oversample_ratio (`float`, *optional*, defaults to 3.0) : Oversampling parameter used for calculating no. of sampled points

importance_sample_ratio (`float`, *optional*, defaults to 0.75) : Ratio of points that are sampled via importance sampling.

init_std (`float`, *optional*, defaults to 0.02) : The standard deviation of the truncated_normal_initializer for initializing all weight matrices.

init_xavier_std (`float`, *optional*, defaults to 1.0) : The scaling factor used for the Xavier initialization gain in the HM Attention map module.

use_auxiliary_loss (`boolean``, *optional*, defaults to `True`) : If `True` `Mask2FormerForUniversalSegmentationOutput` will contain the auxiliary losses computed using the logits from each decoder's stage.

feature_strides (`list[int]`, *optional*, defaults to `[4, 8, 16, 32]`) : Feature strides corresponding to features generated from backbone network.

output_auxiliary_logits (`bool`, *optional*) : Should the model output its `auxiliary_logits` or not.

## MaskFormer specific outputs[[transformers.models.mask2former.modeling_mask2former.Mask2FormerModelOutput]]

#### transformers.models.mask2former.modeling_mask2former.Mask2FormerModelOutput[[transformers.models.mask2former.modeling_mask2former.Mask2FormerModelOutput]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/modeling_mask2former.py#L145)

Class for outputs of [Mask2FormerModel](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerModel). This class returns all the needed hidden states to compute the logits.

**Parameters:**

encoder_last_hidden_state (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`, *optional*) : Last hidden states (final feature map) of the last stage of the encoder model (backbone). Returned when `output_hidden_states=True` is passed.

pixel_decoder_last_hidden_state (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`, *optional*) : Last hidden states (final feature map) of the last stage of the pixel decoder model.

transformer_decoder_last_hidden_state (`tuple(torch.FloatTensor)`) : Final output of the transformer decoder `(batch_size, sequence_length, hidden_size)`.

encoder_hidden_states (`tuple(torch.FloatTensor)`, *optional*) : Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of shape `(batch_size, num_channels, height, width)`. Hidden-states (also called feature maps) of the encoder model at the output of each stage. Returned when `output_hidden_states=True` is passed.

pixel_decoder_hidden_states (`tuple(torch.FloatTensor)`, , *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`) : Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of shape `(batch_size, num_channels, height, width)`. Hidden-states (also called feature maps) of the pixel decoder model at the output of each stage. Returned when `output_hidden_states=True` is passed.

transformer_decoder_hidden_states (`tuple(torch.FloatTensor)`, *optional*) : Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of shape `(batch_size, sequence_length, hidden_size)`. Hidden-states (also called feature maps) of the transformer decoder at the output of each stage. Returned when `output_hidden_states=True` is passed.

transformer_decoder_intermediate_states (`tuple(torch.FloatTensor)` of shape `(num_queries, 1, hidden_size)`) : Intermediate decoder activations, i.e. the output of each decoder layer, each of them gone through a layernorm.

masks_queries_logits (`tuple(torch.FloatTensor)` of shape `(batch_size, num_queries, height, width)`) : Mask Predictions from each layer in the transformer decoder.

attentions (`tuple(tuple(torch.FloatTensor))`, *optional*, returned when `output_attentions=True` is passed) : Tuple of `tuple(torch.FloatTensor)` (one for each layer) of shape `(batch_size, num_heads, sequence_length, sequence_length)`. Self attentions weights from transformer decoder.

attentions (`tuple[torch.FloatTensor]`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`) : Tuple of `torch.FloatTensor` (one for each layer) of shape `(batch_size, num_heads, sequence_length, sequence_length)`.  Attentions weights after the attention softmax, used to compute the weighted average in the self-attention heads.

#### transformers.models.mask2former.modeling_mask2former.Mask2FormerForUniversalSegmentationOutput[[transformers.models.mask2former.modeling_mask2former.Mask2FormerForUniversalSegmentationOutput]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/modeling_mask2former.py#L198)

Class for outputs of `Mask2FormerForUniversalSegmentationOutput`.

This output can be directly passed to [post_process_semantic_segmentation()](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerImageProcessor.post_process_semantic_segmentation) or
[post_process_instance_segmentation()](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerImageProcessor.post_process_instance_segmentation) or
[post_process_panoptic_segmentation()](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerImageProcessor.post_process_panoptic_segmentation) to compute final segmentation maps. Please, see
[`~Mask2FormerImageProcessor] for details regarding usage.

**Parameters:**

loss (`torch.Tensor`, *optional*) : The computed loss, returned when labels are present.

class_queries_logits (`torch.FloatTensor`, *optional*, defaults to `None`) : A tensor of shape `(batch_size, num_queries, num_labels + 1)` representing the proposed classes for each query. Note the `+ 1` is needed because we incorporate the null class.

masks_queries_logits (`torch.FloatTensor`, *optional*, defaults to `None`) : A tensor of shape `(batch_size, num_queries, height, width)` representing the proposed masks for each query.

auxiliary_logits (`list[Dict(str, torch.FloatTensor)]`, *optional*) : List of class and mask predictions from each layer of the transformer decoder.

encoder_last_hidden_state (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`) : Last hidden states (final feature map) of the last stage of the encoder model (backbone).

pixel_decoder_last_hidden_state (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`) : Last hidden states (final feature map) of the last stage of the pixel decoder model.

transformer_decoder_last_hidden_state (`tuple(torch.FloatTensor)`) : Final output of the transformer decoder `(batch_size, sequence_length, hidden_size)`.

encoder_hidden_states (`tuple(torch.FloatTensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`) : Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of shape `(batch_size, num_channels, height, width)`. Hidden-states (also called feature maps) of the encoder model at the output of each stage.

pixel_decoder_hidden_states (`tuple(torch.FloatTensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`) : Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of shape `(batch_size, num_channels, height, width)`. Hidden-states (also called feature maps) of the pixel decoder model at the output of each stage.

transformer_decoder_hidden_states (`tuple(torch.FloatTensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`) : Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of shape `(batch_size, sequence_length, hidden_size)`. Hidden-states (also called feature maps) of the transformer decoder at the output of each stage.

attentions (`tuple(tuple(torch.FloatTensor))`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`) : Tuple of `tuple(torch.FloatTensor)` (one for each layer) of shape `(batch_size, num_heads, sequence_length, sequence_length)`. Self and Cross Attentions weights from transformer decoder.

## Mask2FormerModel[[transformers.Mask2FormerModel]]

#### transformers.Mask2FormerModel[[transformers.Mask2FormerModel]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/modeling_mask2former.py#L2169)

The bare Mask2Former Model outputting raw hidden-states without any specific head on top.

This model inherits from [PreTrainedModel](/docs/transformers/v5.0.0rc1/en/main_classes/model#transformers.PreTrainedModel). Check the superclass documentation for the generic methods the
library implements for all its model (such as downloading or saving, resizing the input embeddings, pruning heads
etc.)

This model is also a PyTorch [torch.nn.Module](https://pytorch.org/docs/stable/nn.html#torch.nn.Module) subclass.
Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage
and behavior.

forwardtransformers.Mask2FormerModel.forwardhttps://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/modeling_mask2former.py#L2179[{"name": "pixel_values", "val": ": Tensor"}, {"name": "pixel_mask", "val": ": typing.Optional[torch.Tensor] = None"}, {"name": "output_hidden_states", "val": ": typing.Optional[bool] = None"}, {"name": "output_attentions", "val": ": typing.Optional[bool] = None"}, {"name": "return_dict", "val": ": typing.Optional[bool] = None"}, {"name": "**kwargs", "val": ""}]- **pixel_values** (`torch.Tensor` of shape `(batch_size, num_channels, image_size, image_size)`) --
  The tensors corresponding to the input images. Pixel values can be obtained using
  [Mask2FormerImageProcessor](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerImageProcessor). See `Mask2FormerImageProcessor.__call__()` for details (`processor_class` uses
  [Mask2FormerImageProcessor](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerImageProcessor) for processing images).
- **pixel_mask** (`torch.Tensor` of shape `(batch_size, height, width)`, *optional*) --
  Mask to avoid performing attention on padding pixel values. Mask values selected in `[0, 1]`:

  - 1 for pixels that are real (i.e. **not masked**),
  - 0 for pixels that are padding (i.e. **masked**).

  [What are attention masks?](../glossary#attention-mask)
- **output_hidden_states** (`bool`, *optional*) --
  Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for
  more detail.
- **output_attentions** (`bool`, *optional*) --
  Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned
  tensors for more detail.
- **return_dict** (`bool`, *optional*) --
  Whether or not to return a [ModelOutput](/docs/transformers/v5.0.0rc1/en/main_classes/output#transformers.utils.ModelOutput) instead of a plain tuple.0[transformers.models.mask2former.modeling_mask2former.Mask2FormerModelOutput](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.models.mask2former.modeling_mask2former.Mask2FormerModelOutput) or `tuple(torch.FloatTensor)`A [transformers.models.mask2former.modeling_mask2former.Mask2FormerModelOutput](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.models.mask2former.modeling_mask2former.Mask2FormerModelOutput) or a tuple of
`torch.FloatTensor` (if `return_dict=False` is passed or when `config.return_dict=False`) comprising various
elements depending on the configuration ([Mask2FormerConfig](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerConfig)) and inputs.

- **encoder_last_hidden_state** (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`, *optional*) -- Last hidden states (final feature map) of the last stage of the encoder model (backbone). Returned when
  `output_hidden_states=True` is passed.
- **pixel_decoder_last_hidden_state** (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`, *optional*) -- Last hidden states (final feature map) of the last stage of the pixel decoder model.
- **transformer_decoder_last_hidden_state** (`tuple(torch.FloatTensor)`) -- Final output of the transformer decoder `(batch_size, sequence_length, hidden_size)`.
- **encoder_hidden_states** (`tuple(torch.FloatTensor)`, *optional*) -- Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of
  shape `(batch_size, num_channels, height, width)`. Hidden-states (also called feature maps) of the encoder
  model at the output of each stage. Returned when `output_hidden_states=True` is passed.
- **pixel_decoder_hidden_states** (`tuple(torch.FloatTensor)`, , *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`) -- Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of
  shape `(batch_size, num_channels, height, width)`. Hidden-states (also called feature maps) of the pixel
  decoder model at the output of each stage. Returned when `output_hidden_states=True` is passed.
- **transformer_decoder_hidden_states** (`tuple(torch.FloatTensor)`, *optional*) -- Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of
  shape `(batch_size, sequence_length, hidden_size)`. Hidden-states (also called feature maps) of the
  transformer decoder at the output of each stage. Returned when `output_hidden_states=True` is passed.
- **transformer_decoder_intermediate_states** (`tuple(torch.FloatTensor)` of shape `(num_queries, 1, hidden_size)`) -- Intermediate decoder activations, i.e. the output of each decoder layer, each of them gone through a
  layernorm.
- **masks_queries_logits** (`tuple(torch.FloatTensor)` of shape `(batch_size, num_queries, height, width)`)
  Mask Predictions from each layer in the transformer decoder.
- **attentions** (`tuple(tuple(torch.FloatTensor))`, *optional*, returned when `output_attentions=True` is passed) -- Tuple of `tuple(torch.FloatTensor)` (one for each layer) of shape `(batch_size, num_heads, sequence_length,
  sequence_length)`. Self attentions weights from transformer decoder.
- **attentions** (`tuple[torch.FloatTensor]`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`) -- Tuple of `torch.FloatTensor` (one for each layer) of shape `(batch_size, num_heads, sequence_length,
  sequence_length)`.

  Attentions weights after the attention softmax, used to compute the weighted average in the self-attention
  heads.
The [Mask2FormerModel](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerModel) forward method, overrides the `__call__` special method.

Although the recipe for forward pass needs to be defined within this function, one should call the `Module`
instance afterwards instead of this since the former takes care of running the pre and post processing steps while
the latter silently ignores them.

**Parameters:**

config ([Mask2FormerConfig](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerConfig)) : Model configuration class with all the parameters of the model. Initializing with a config file does not load the weights associated with the model, only the configuration. Check out the [from_pretrained()](/docs/transformers/v5.0.0rc1/en/main_classes/model#transformers.PreTrainedModel.from_pretrained) method to load the model weights.

**Returns:**

`[transformers.models.mask2former.modeling_mask2former.Mask2FormerModelOutput](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.models.mask2former.modeling_mask2former.Mask2FormerModelOutput) or `tuple(torch.FloatTensor)``

A [transformers.models.mask2former.modeling_mask2former.Mask2FormerModelOutput](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.models.mask2former.modeling_mask2former.Mask2FormerModelOutput) or a tuple of
`torch.FloatTensor` (if `return_dict=False` is passed or when `config.return_dict=False`) comprising various
elements depending on the configuration ([Mask2FormerConfig](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerConfig)) and inputs.

- **encoder_last_hidden_state** (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`, *optional*) -- Last hidden states (final feature map) of the last stage of the encoder model (backbone). Returned when
  `output_hidden_states=True` is passed.
- **pixel_decoder_last_hidden_state** (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`, *optional*) -- Last hidden states (final feature map) of the last stage of the pixel decoder model.
- **transformer_decoder_last_hidden_state** (`tuple(torch.FloatTensor)`) -- Final output of the transformer decoder `(batch_size, sequence_length, hidden_size)`.
- **encoder_hidden_states** (`tuple(torch.FloatTensor)`, *optional*) -- Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of
  shape `(batch_size, num_channels, height, width)`. Hidden-states (also called feature maps) of the encoder
  model at the output of each stage. Returned when `output_hidden_states=True` is passed.
- **pixel_decoder_hidden_states** (`tuple(torch.FloatTensor)`, , *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`) -- Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of
  shape `(batch_size, num_channels, height, width)`. Hidden-states (also called feature maps) of the pixel
  decoder model at the output of each stage. Returned when `output_hidden_states=True` is passed.
- **transformer_decoder_hidden_states** (`tuple(torch.FloatTensor)`, *optional*) -- Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of
  shape `(batch_size, sequence_length, hidden_size)`. Hidden-states (also called feature maps) of the
  transformer decoder at the output of each stage. Returned when `output_hidden_states=True` is passed.
- **transformer_decoder_intermediate_states** (`tuple(torch.FloatTensor)` of shape `(num_queries, 1, hidden_size)`) -- Intermediate decoder activations, i.e. the output of each decoder layer, each of them gone through a
  layernorm.
- **masks_queries_logits** (`tuple(torch.FloatTensor)` of shape `(batch_size, num_queries, height, width)`)
  Mask Predictions from each layer in the transformer decoder.
- **attentions** (`tuple(tuple(torch.FloatTensor))`, *optional*, returned when `output_attentions=True` is passed) -- Tuple of `tuple(torch.FloatTensor)` (one for each layer) of shape `(batch_size, num_heads, sequence_length,
  sequence_length)`. Self attentions weights from transformer decoder.
- **attentions** (`tuple[torch.FloatTensor]`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`) -- Tuple of `torch.FloatTensor` (one for each layer) of shape `(batch_size, num_heads, sequence_length,
  sequence_length)`.

  Attentions weights after the attention softmax, used to compute the weighted average in the self-attention
  heads.

## Mask2FormerForUniversalSegmentation[[transformers.Mask2FormerForUniversalSegmentation]]

#### transformers.Mask2FormerForUniversalSegmentation[[transformers.Mask2FormerForUniversalSegmentation]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/modeling_mask2former.py#L2245)

The Mask2Former Model with heads on top for instance/semantic/panoptic segmentation.

This model inherits from [PreTrainedModel](/docs/transformers/v5.0.0rc1/en/main_classes/model#transformers.PreTrainedModel). Check the superclass documentation for the generic methods the
library implements for all its model (such as downloading or saving, resizing the input embeddings, pruning heads
etc.)

This model is also a PyTorch [torch.nn.Module](https://pytorch.org/docs/stable/nn.html#torch.nn.Module) subclass.
Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage
and behavior.

forwardtransformers.Mask2FormerForUniversalSegmentation.forwardhttps://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/modeling_mask2former.py#L2298[{"name": "pixel_values", "val": ": Tensor"}, {"name": "mask_labels", "val": ": typing.Optional[list[torch.Tensor]] = None"}, {"name": "class_labels", "val": ": typing.Optional[list[torch.Tensor]] = None"}, {"name": "pixel_mask", "val": ": typing.Optional[torch.Tensor] = None"}, {"name": "output_hidden_states", "val": ": typing.Optional[bool] = None"}, {"name": "output_auxiliary_logits", "val": ": typing.Optional[bool] = None"}, {"name": "output_attentions", "val": ": typing.Optional[bool] = None"}, {"name": "return_dict", "val": ": typing.Optional[bool] = None"}, {"name": "**kwargs", "val": ""}]- **pixel_values** (`torch.Tensor` of shape `(batch_size, num_channels, image_size, image_size)`) --
  The tensors corresponding to the input images. Pixel values can be obtained using
  [Mask2FormerImageProcessor](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerImageProcessor). See `Mask2FormerImageProcessor.__call__()` for details (`processor_class` uses
  [Mask2FormerImageProcessor](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerImageProcessor) for processing images).
- **mask_labels** (`list[torch.Tensor]`, *optional*) --
  List of mask labels of shape `(num_labels, height, width)` to be fed to a model
- **class_labels** (`list[torch.LongTensor]`, *optional*) --
  list of target class labels of shape `(num_labels, height, width)` to be fed to a model. They identify the
  labels of `mask_labels`, e.g. the label of `mask_labels[i][j]` if `class_labels[i][j]`.
- **pixel_mask** (`torch.Tensor` of shape `(batch_size, height, width)`, *optional*) --
  Mask to avoid performing attention on padding pixel values. Mask values selected in `[0, 1]`:

  - 1 for pixels that are real (i.e. **not masked**),
  - 0 for pixels that are padding (i.e. **masked**).

  [What are attention masks?](../glossary#attention-mask)
- **output_hidden_states** (`bool`, *optional*) --
  Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for
  more detail.
- **output_auxiliary_logits** (`bool`, *optional*) --
  Whether or not to output auxiliary logits.
- **output_attentions** (`bool`, *optional*) --
  Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned
  tensors for more detail.
- **return_dict** (`bool`, *optional*) --
  Whether or not to return a [ModelOutput](/docs/transformers/v5.0.0rc1/en/main_classes/output#transformers.utils.ModelOutput) instead of a plain tuple.0[transformers.models.mask2former.modeling_mask2former.Mask2FormerForUniversalSegmentationOutput](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.models.mask2former.modeling_mask2former.Mask2FormerForUniversalSegmentationOutput) or `tuple(torch.FloatTensor)`A [transformers.models.mask2former.modeling_mask2former.Mask2FormerForUniversalSegmentationOutput](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.models.mask2former.modeling_mask2former.Mask2FormerForUniversalSegmentationOutput) or a tuple of
`torch.FloatTensor` (if `return_dict=False` is passed or when `config.return_dict=False`) comprising various
elements depending on the configuration ([Mask2FormerConfig](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerConfig)) and inputs.

- **loss** (`torch.Tensor`, *optional*) -- The computed loss, returned when labels are present.
- **class_queries_logits** (`torch.FloatTensor`, *optional*, defaults to `None`) -- A tensor of shape `(batch_size, num_queries, num_labels + 1)` representing the proposed classes for each
  query. Note the `+ 1` is needed because we incorporate the null class.
- **masks_queries_logits** (`torch.FloatTensor`, *optional*, defaults to `None`) -- A tensor of shape `(batch_size, num_queries, height, width)` representing the proposed masks for each
  query.
- **auxiliary_logits** (`list[Dict(str, torch.FloatTensor)]`, *optional*) -- List of class and mask predictions from each layer of the transformer decoder.
- **encoder_last_hidden_state** (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`) -- Last hidden states (final feature map) of the last stage of the encoder model (backbone).
- **pixel_decoder_last_hidden_state** (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`) -- Last hidden states (final feature map) of the last stage of the pixel decoder model.
- **transformer_decoder_last_hidden_state** (`tuple(torch.FloatTensor)`) -- Final output of the transformer decoder `(batch_size, sequence_length, hidden_size)`.
- **encoder_hidden_states** (`tuple(torch.FloatTensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`) -- Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of
  shape `(batch_size, num_channels, height, width)`. Hidden-states (also called feature maps) of the encoder
  model at the output of each stage.
- **pixel_decoder_hidden_states** (`tuple(torch.FloatTensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`) -- Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of
  shape `(batch_size, num_channels, height, width)`. Hidden-states (also called feature maps) of the pixel
  decoder model at the output of each stage.
- **transformer_decoder_hidden_states** (`tuple(torch.FloatTensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`) -- Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of
  shape `(batch_size, sequence_length, hidden_size)`. Hidden-states (also called feature maps) of the
  transformer decoder at the output of each stage.
- **attentions** (`tuple(tuple(torch.FloatTensor))`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`) -- Tuple of `tuple(torch.FloatTensor)` (one for each layer) of shape `(batch_size, num_heads, sequence_length,
  sequence_length)`. Self and Cross Attentions weights from transformer decoder.
The [Mask2FormerForUniversalSegmentation](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerForUniversalSegmentation) forward method, overrides the `__call__` special method.

Although the recipe for forward pass needs to be defined within this function, one should call the `Module`
instance afterwards instead of this since the former takes care of running the pre and post processing steps while
the latter silently ignores them.

Examples:

Instance segmentation example:

```python
>>> from transformers import AutoImageProcessor, Mask2FormerForUniversalSegmentation
>>> from PIL import Image
>>> import requests
>>> import torch

>>> # Load Mask2Former trained on COCO instance segmentation dataset
>>> image_processor = AutoImageProcessor.from_pretrained("facebook/mask2former-swin-small-coco-instance")
>>> model = Mask2FormerForUniversalSegmentation.from_pretrained(
...     "facebook/mask2former-swin-small-coco-instance"
... )

>>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
>>> image = Image.open(requests.get(url, stream=True).raw)
>>> inputs = image_processor(image, return_tensors="pt")

>>> with torch.no_grad():
...     outputs = model(**inputs)

>>> # Model predicts class_queries_logits of shape `(batch_size, num_queries)`
>>> # and masks_queries_logits of shape `(batch_size, num_queries, height, width)`
>>> class_queries_logits = outputs.class_queries_logits
>>> masks_queries_logits = outputs.masks_queries_logits

>>> # Perform post-processing to get instance segmentation map
>>> pred_instance_map = image_processor.post_process_instance_segmentation(
...     outputs, target_sizes=[(image.height, image.width)]
... )[0]
>>> print(pred_instance_map.shape)
torch.Size([480, 640])
```

Semantic segmentation example:
```python
>>> from transformers import AutoImageProcessor, Mask2FormerForUniversalSegmentation
>>> from PIL import Image
>>> import requests
>>> import torch

>>> # Load Mask2Former trained on ADE20k semantic segmentation dataset
>>> image_processor = AutoImageProcessor.from_pretrained("facebook/mask2former-swin-small-ade-semantic")
>>> model = Mask2FormerForUniversalSegmentation.from_pretrained("facebook/mask2former-swin-small-ade-semantic")

>>> url = (
...     "https://huggingface.co/datasets/hf-internal-testing/fixtures_ade20k/resolve/main/ADE_val_00000001.jpg"
... )
>>> image = Image.open(requests.get(url, stream=True).raw)
>>> inputs = image_processor(image, return_tensors="pt")

>>> with torch.no_grad():
...     outputs = model(**inputs)

>>> # Model predicts class_queries_logits of shape `(batch_size, num_queries)`
>>> # and masks_queries_logits of shape `(batch_size, num_queries, height, width)`
>>> class_queries_logits = outputs.class_queries_logits
>>> masks_queries_logits = outputs.masks_queries_logits

>>> # Perform post-processing to get semantic segmentation map
>>> pred_semantic_map = image_processor.post_process_semantic_segmentation(
...     outputs, target_sizes=[(image.height, image.width)]
... )[0]
>>> print(pred_semantic_map.shape)
torch.Size([512, 683])
```

Panoptic segmentation example:

```python
>>> from transformers import AutoImageProcessor, Mask2FormerForUniversalSegmentation
>>> from PIL import Image
>>> import requests
>>> import torch

>>> # Load Mask2Former trained on CityScapes panoptic segmentation dataset
>>> image_processor = AutoImageProcessor.from_pretrained("facebook/mask2former-swin-small-cityscapes-panoptic")
>>> model = Mask2FormerForUniversalSegmentation.from_pretrained(
...     "facebook/mask2former-swin-small-cityscapes-panoptic"
... )

>>> url = "https://cdn-media.huggingface.co/Inference-API/Sample-results-on-the-Cityscapes-dataset-The-above-images-show-how-our-method-can-handle.png"
>>> image = Image.open(requests.get(url, stream=True).raw)
>>> inputs = image_processor(image, return_tensors="pt")

>>> with torch.no_grad():
...     outputs = model(**inputs)

>>> # Model predicts class_queries_logits of shape `(batch_size, num_queries)`
>>> # and masks_queries_logits of shape `(batch_size, num_queries, height, width)`
>>> class_queries_logits = outputs.class_queries_logits
>>> masks_queries_logits = outputs.masks_queries_logits

>>> # Perform post-processing to get panoptic segmentation map
>>> pred_panoptic_map = image_processor.post_process_panoptic_segmentation(
...     outputs, target_sizes=[(image.height, image.width)]
... )[0]["segmentation"]
>>> print(pred_panoptic_map.shape)
torch.Size([338, 676])
```

**Parameters:**

config ([Mask2FormerConfig](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerConfig)) : Model configuration class with all the parameters of the model. Initializing with a config file does not load the weights associated with the model, only the configuration. Check out the [from_pretrained()](/docs/transformers/v5.0.0rc1/en/main_classes/model#transformers.PreTrainedModel.from_pretrained) method to load the model weights.

**Returns:**

`[transformers.models.mask2former.modeling_mask2former.Mask2FormerForUniversalSegmentationOutput](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.models.mask2former.modeling_mask2former.Mask2FormerForUniversalSegmentationOutput) or `tuple(torch.FloatTensor)``

A [transformers.models.mask2former.modeling_mask2former.Mask2FormerForUniversalSegmentationOutput](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.models.mask2former.modeling_mask2former.Mask2FormerForUniversalSegmentationOutput) or a tuple of
`torch.FloatTensor` (if `return_dict=False` is passed or when `config.return_dict=False`) comprising various
elements depending on the configuration ([Mask2FormerConfig](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerConfig)) and inputs.

- **loss** (`torch.Tensor`, *optional*) -- The computed loss, returned when labels are present.
- **class_queries_logits** (`torch.FloatTensor`, *optional*, defaults to `None`) -- A tensor of shape `(batch_size, num_queries, num_labels + 1)` representing the proposed classes for each
  query. Note the `+ 1` is needed because we incorporate the null class.
- **masks_queries_logits** (`torch.FloatTensor`, *optional*, defaults to `None`) -- A tensor of shape `(batch_size, num_queries, height, width)` representing the proposed masks for each
  query.
- **auxiliary_logits** (`list[Dict(str, torch.FloatTensor)]`, *optional*) -- List of class and mask predictions from each layer of the transformer decoder.
- **encoder_last_hidden_state** (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`) -- Last hidden states (final feature map) of the last stage of the encoder model (backbone).
- **pixel_decoder_last_hidden_state** (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`) -- Last hidden states (final feature map) of the last stage of the pixel decoder model.
- **transformer_decoder_last_hidden_state** (`tuple(torch.FloatTensor)`) -- Final output of the transformer decoder `(batch_size, sequence_length, hidden_size)`.
- **encoder_hidden_states** (`tuple(torch.FloatTensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`) -- Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of
  shape `(batch_size, num_channels, height, width)`. Hidden-states (also called feature maps) of the encoder
  model at the output of each stage.
- **pixel_decoder_hidden_states** (`tuple(torch.FloatTensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`) -- Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of
  shape `(batch_size, num_channels, height, width)`. Hidden-states (also called feature maps) of the pixel
  decoder model at the output of each stage.
- **transformer_decoder_hidden_states** (`tuple(torch.FloatTensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`) -- Tuple of `torch.FloatTensor` (one for the output of the embeddings + one for the output of each stage) of
  shape `(batch_size, sequence_length, hidden_size)`. Hidden-states (also called feature maps) of the
  transformer decoder at the output of each stage.
- **attentions** (`tuple(tuple(torch.FloatTensor))`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`) -- Tuple of `tuple(torch.FloatTensor)` (one for each layer) of shape `(batch_size, num_heads, sequence_length,
  sequence_length)`. Self and Cross Attentions weights from transformer decoder.

## Mask2FormerImageProcessor[[transformers.Mask2FormerImageProcessor]]

#### transformers.Mask2FormerImageProcessor[[transformers.Mask2FormerImageProcessor]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/image_processing_mask2former.py#L371)

Constructs a Mask2Former image processor. The image processor can be used to prepare image(s) and optional targets
for the model.

This image processor inherits from [BaseImageProcessor](/docs/transformers/v5.0.0rc1/en/main_classes/image_processor#transformers.BaseImageProcessor) which contains most of the main methods. Users should
refer to this superclass for more information regarding those methods.

preprocesstransformers.Mask2FormerImageProcessor.preprocesshttps://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/image_processing_mask2former.py#L685[{"name": "images", "val": ": typing.Union[ForwardRef('PIL.Image.Image'), numpy.ndarray, ForwardRef('torch.Tensor'), list['PIL.Image.Image'], list[numpy.ndarray], list['torch.Tensor']]"}, {"name": "segmentation_maps", "val": ": typing.Union[ForwardRef('PIL.Image.Image'), numpy.ndarray, ForwardRef('torch.Tensor'), list['PIL.Image.Image'], list[numpy.ndarray], list['torch.Tensor'], NoneType] = None"}, {"name": "instance_id_to_semantic_id", "val": ": typing.Optional[dict[int, int]] = None"}, {"name": "do_resize", "val": ": typing.Optional[bool] = None"}, {"name": "size", "val": ": typing.Optional[dict[str, int]] = None"}, {"name": "size_divisor", "val": ": typing.Optional[int] = None"}, {"name": "resample", "val": ": typing.Optional[PIL.Image.Resampling] = None"}, {"name": "do_rescale", "val": ": typing.Optional[bool] = None"}, {"name": "rescale_factor", "val": ": typing.Optional[float] = None"}, {"name": "do_normalize", "val": ": typing.Optional[bool] = None"}, {"name": "image_mean", "val": ": typing.Union[float, list[float], NoneType] = None"}, {"name": "image_std", "val": ": typing.Union[float, list[float], NoneType] = None"}, {"name": "ignore_index", "val": ": typing.Optional[int] = None"}, {"name": "do_reduce_labels", "val": ": typing.Optional[bool] = None"}, {"name": "return_tensors", "val": ": typing.Union[str, transformers.utils.generic.TensorType, NoneType] = None"}, {"name": "data_format", "val": ": typing.Union[str, transformers.image_utils.ChannelDimension] = "}, {"name": "input_data_format", "val": ": typing.Union[str, transformers.image_utils.ChannelDimension, NoneType] = None"}, {"name": "pad_size", "val": ": typing.Optional[dict[str, int]] = None"}]

**Parameters:**

do_resize (`bool`, *optional*, defaults to `True`) : Whether to resize the input to a certain `size`.

size (`int`, *optional*, defaults to 800) : Resize the input to the given size. Only has an effect if `do_resize` is set to `True`. If size is a sequence like `(width, height)`, output size will be matched to this. If size is an int, smaller edge of the image will be matched to this number. i.e, if `height > width`, then image will be rescaled to `(size * height / width, size)`.

size_divisor (`int`, *optional*, defaults to 32) : Some backbones need images divisible by a certain number. If not passed, it defaults to the value used in Swin Transformer.

resample (`int`, *optional*, defaults to `Resampling.BILINEAR`) : An optional resampling filter. This can be one of `PIL.Image.Resampling.NEAREST`, `PIL.Image.Resampling.BOX`, `PIL.Image.Resampling.BILINEAR`, `PIL.Image.Resampling.HAMMING`, `PIL.Image.Resampling.BICUBIC` or `PIL.Image.Resampling.LANCZOS`. Only has an effect if `do_resize` is set to `True`.

do_rescale (`bool`, *optional*, defaults to `True`) : Whether to rescale the input to a certain `scale`.

rescale_factor (`float`, *optional*, defaults to `1/ 255`) : Rescale the input by the given factor. Only has an effect if `do_rescale` is set to `True`.

do_normalize (`bool`, *optional*, defaults to `True`) : Whether or not to normalize the input with mean and standard deviation.

image_mean (`int`, *optional*, defaults to `[0.485, 0.456, 0.406]`) : The sequence of means for each channel, to be used when normalizing images. Defaults to the ImageNet mean.

image_std (`int`, *optional*, defaults to `[0.229, 0.224, 0.225]`) : The sequence of standard deviations for each channel, to be used when normalizing images. Defaults to the ImageNet std.

ignore_index (`int`, *optional*) : Label to be assigned to background pixels in segmentation maps. If provided, segmentation map pixels denoted with 0 (background) will be replaced with `ignore_index`.

do_reduce_labels (`bool`, *optional*, defaults to `False`) : Whether or not to decrement all label values of segmentation maps by 1. Usually used for datasets where 0 is used for background, and background itself is not included in all classes of a dataset (e.g. ADE20k). The background label will be replaced by `ignore_index`.

num_labels (`int`, *optional*) : The number of labels in the segmentation map.

pad_size (`Dict[str, int]`, *optional*) : The size `{"height": int, "width" int}` to pad the images to. Must be larger than any image size provided for preprocessing. If `pad_size` is not provided, images will be padded to the largest height and width in the batch.
#### encode_inputs[[transformers.Mask2FormerImageProcessor.encode_inputs]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/image_processing_mask2former.py#L875)

Pad images up to the largest image in a batch and create a corresponding `pixel_mask`.

Mask2Former addresses semantic segmentation with a mask classification paradigm, thus input segmentation maps
will be converted to lists of binary masks and their respective labels. Let's see an example, assuming
`segmentation_maps = [[2,6,7,9]]`, the output will contain `mask_labels =
[[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]` (four binary masks) and `class_labels = [2,6,7,9]`, the labels for
each mask.

**Parameters:**

pixel_values_list (`list[ImageInput]`) : List of images (pixel values) to be padded. Each image should be a tensor of shape `(channels, height, width)`. 

segmentation_maps (`ImageInput`, *optional*) : The corresponding semantic segmentation maps with the pixel-wise annotations.  (`bool`, *optional*, defaults to `True`): Whether or not to pad images up to the largest image in a batch and create a pixel mask.  If left to the default, will return a pixel mask that is:  - 1 for pixels that are real (i.e. **not masked**), - 0 for pixels that are padding (i.e. **masked**). 

instance_id_to_semantic_id (`list[dict[int, int]]` or `dict[int, int]`, *optional*) : A mapping between object instance ids and class ids. If passed, `segmentation_maps` is treated as an instance segmentation map where each pixel represents an instance id. Can be provided as a single dictionary with a global/dataset-level mapping or as a list of dictionaries (one per image), to map instance ids in each image separately. 

return_tensors (`str` or [TensorType](/docs/transformers/v5.0.0rc1/en/internal/file_utils#transformers.TensorType), *optional*) : If set, will return tensors instead of NumPy arrays. If set to `'pt'`, return PyTorch `torch.Tensor` objects. 

input_data_format (`ChannelDimension` or `str`, *optional*) : The channel dimension format of the input image. If not provided, it will be inferred. 

pad_size (`Dict[str, int]`, *optional*) : The size `{"height": int, "width" int}` to pad the images to. Must be larger than any image size provided for preprocessing. If `pad_size` is not provided, images will be padded to the largest height and width in the batch.

**Returns:**

`[BatchFeature](/docs/transformers/v5.0.0rc1/en/main_classes/image_processor#transformers.BatchFeature)`

A [BatchFeature](/docs/transformers/v5.0.0rc1/en/main_classes/image_processor#transformers.BatchFeature) with the following fields:

- **pixel_values** -- Pixel values to be fed to a model.
- **pixel_mask** -- Pixel mask to be fed to a model (when `=True` or if `pixel_mask` is in
  `self.model_input_names`).
- **mask_labels** -- Optional list of mask labels of shape `(labels, height, width)` to be fed to a model
  (when `annotations` are provided).
- **class_labels** -- Optional list of class labels of shape `(labels)` to be fed to a model (when
  `annotations` are provided). They identify the labels of `mask_labels`, e.g. the label of
  `mask_labels[i][j]` if `class_labels[i][j]`.
#### post_process_semantic_segmentation[[transformers.Mask2FormerImageProcessor.post_process_semantic_segmentation]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/image_processing_mask2former.py#L988)

Converts the output of [Mask2FormerForUniversalSegmentation](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerForUniversalSegmentation) into semantic segmentation maps. Only supports
PyTorch.

**Parameters:**

outputs ([Mask2FormerForUniversalSegmentation](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerForUniversalSegmentation)) : Raw outputs of the model.

target_sizes (`list[tuple[int, int]]`, *optional*) : List of length (batch_size), where each list item (`tuple[int, int]]`) corresponds to the requested final size (height, width) of each prediction. If left to None, predictions will not be resized.

**Returns:**

``list[torch.Tensor]``

A list of length `batch_size`, where each item is a semantic segmentation map of shape (height, width)
corresponding to the target_sizes entry (if `target_sizes` is specified). Each entry of each
`torch.Tensor` correspond to a semantic class id.
#### post_process_instance_segmentation[[transformers.Mask2FormerImageProcessor.post_process_instance_segmentation]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/image_processing_mask2former.py#L1043)

Converts the output of `Mask2FormerForUniversalSegmentationOutput` into instance segmentation predictions.
Only supports PyTorch. If instances could overlap, set either return_coco_annotation or return_binary_maps
to `True` to get the correct segmentation result.

**Parameters:**

outputs ([Mask2FormerForUniversalSegmentation](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerForUniversalSegmentation)) : Raw outputs of the model.

threshold (`float`, *optional*, defaults to 0.5) : The probability score threshold to keep predicted instance masks.

mask_threshold (`float`, *optional*, defaults to 0.5) : Threshold to use when turning the predicted masks into binary values.

overlap_mask_area_threshold (`float`, *optional*, defaults to 0.8) : The overlap mask area threshold to merge or discard small disconnected parts within each binary instance mask.

target_sizes (`list[Tuple]`, *optional*) : List of length (batch_size), where each list item (`tuple[int, int]]`) corresponds to the requested final size (height, width) of each prediction. If left to None, predictions will not be resized.

return_coco_annotation (`bool`, *optional*, defaults to `False`) : If set to `True`, segmentation maps are returned in COCO run-length encoding (RLE) format.

return_binary_maps (`bool`, *optional*, defaults to `False`) : If set to `True`, segmentation maps are returned as a concatenated tensor of binary segmentation maps (one per detected instance).

**Returns:**

``list[Dict]``

A list of dictionaries, one per image, each dictionary containing two keys:
- **segmentation** -- A tensor of shape `(height, width)` where each pixel represents a `segment_id`, or
  `list[List]` run-length encoding (RLE) of the segmentation map if return_coco_annotation is set to
  `True`, or a tensor of shape `(num_instances, height, width)` if return_binary_maps is set to `True`.
  Set to `None` if no mask if found above `threshold`.
- **segments_info** -- A dictionary that contains additional information on each segment.
  - **id** -- An integer representing the `segment_id`.
  - **label_id** -- An integer representing the label / semantic class id corresponding to `segment_id`.
  - **score** -- Prediction score of segment with `segment_id`.
#### post_process_panoptic_segmentation[[transformers.Mask2FormerImageProcessor.post_process_panoptic_segmentation]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/image_processing_mask2former.py#L1164)

Converts the output of `Mask2FormerForUniversalSegmentationOutput` into image panoptic segmentation
predictions. Only supports PyTorch.

**Parameters:**

outputs (`Mask2FormerForUniversalSegmentationOutput`) : The outputs from [Mask2FormerForUniversalSegmentation](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerForUniversalSegmentation).

threshold (`float`, *optional*, defaults to 0.5) : The probability score threshold to keep predicted instance masks.

mask_threshold (`float`, *optional*, defaults to 0.5) : Threshold to use when turning the predicted masks into binary values.

overlap_mask_area_threshold (`float`, *optional*, defaults to 0.8) : The overlap mask area threshold to merge or discard small disconnected parts within each binary instance mask.

label_ids_to_fuse (`Set[int]`, *optional*) : The labels in this state will have all their instances be fused together. For instance we could say there can only be one sky in an image, but several persons, so the label ID for sky would be in that set, but not the one for person.

target_sizes (`list[Tuple]`, *optional*) : List of length (batch_size), where each list item (`tuple[int, int]]`) corresponds to the requested final size (height, width) of each prediction in batch. If left to None, predictions will not be resized.

**Returns:**

``list[Dict]``

A list of dictionaries, one per image, each dictionary containing two keys:
- **segmentation** -- a tensor of shape `(height, width)` where each pixel represents a `segment_id`, set
  to `None` if no mask if found above `threshold`. If `target_sizes` is specified, segmentation is resized
  to the corresponding `target_sizes` entry.
- **segments_info** -- A dictionary that contains additional information on each segment.
  - **id** -- an integer representing the `segment_id`.
  - **label_id** -- An integer representing the label / semantic class id corresponding to `segment_id`.
  - **was_fused** -- a boolean, `True` if `label_id` was in `label_ids_to_fuse`, `False` otherwise.
    Multiple instances of the same class / label were fused and assigned a single `segment_id`.
  - **score** -- Prediction score of segment with `segment_id`.

## Mask2FormerImageProcessorFast[[transformers.Mask2FormerImageProcessorFast]]

#### transformers.Mask2FormerImageProcessorFast[[transformers.Mask2FormerImageProcessorFast]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/image_processing_mask2former_fast.py#L95)

Constructs a fast Mask2Former image processor.

preprocesstransformers.Mask2FormerImageProcessorFast.preprocesshttps://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/image_processing_mask2former_fast.py#L232[{"name": "images", "val": ": typing.Union[ForwardRef('PIL.Image.Image'), numpy.ndarray, ForwardRef('torch.Tensor'), list['PIL.Image.Image'], list[numpy.ndarray], list['torch.Tensor']]"}, {"name": "segmentation_maps", "val": ": typing.Union[ForwardRef('PIL.Image.Image'), numpy.ndarray, ForwardRef('torch.Tensor'), list['PIL.Image.Image'], list[numpy.ndarray], list['torch.Tensor'], NoneType] = None"}, {"name": "instance_id_to_semantic_id", "val": ": typing.Union[list[dict[int, int]], dict[int, int], NoneType] = None"}, {"name": "**kwargs", "val": ": typing_extensions.Unpack[transformers.models.mask2former.image_processing_mask2former.Mask2FormerImageProcessorKwargs]"}]- **images** (`Union[PIL.Image.Image, numpy.ndarray, torch.Tensor, list['PIL.Image.Image'], list[numpy.ndarray], list['torch.Tensor']]`) --
  Image to preprocess. Expects a single or batch of images with pixel values ranging from 0 to 255. If
  passing in images with pixel values between 0 and 1, set `do_rescale=False`.
- **segmentation_maps** (`ImageInput`, *optional*) --
  The segmentation maps.
- **instance_id_to_semantic_id** (`Union[list[dict[int, int]], dict[int, int]]`, *optional*) --
  A mapping from instance IDs to semantic IDs.
- **do_convert_rgb** (`bool`, *optional*) --
  Whether to convert the image to RGB.
- **do_resize** (`bool`, *optional*) --
  Whether to resize the image.
- **size** (`Annotated[Union[int, list[int], tuple[int, ...], dict[str, int], NoneType], None]`) --
  Describes the maximum input dimensions to the model.
- **crop_size** (`Annotated[Union[int, list[int], tuple[int, ...], dict[str, int], NoneType], None]`) --
  Size of the output image after applying `center_crop`.
- **resample** (`Annotated[Union[PILImageResampling, int, NoneType], None]`) --
  Resampling filter to use if resizing the image. This can be one of the enum `PILImageResampling`. Only
  has an effect if `do_resize` is set to `True`.
- **do_rescale** (`bool`, *optional*) --
  Whether to rescale the image.
- **rescale_factor** (`float`, *optional*) --
  Rescale factor to rescale the image by if `do_rescale` is set to `True`.
- **do_normalize** (`bool`, *optional*) --
  Whether to normalize the image.
- **image_mean** (`Union[float, list[float], tuple[float, ...], NoneType]`) --
  Image mean to use for normalization. Only has an effect if `do_normalize` is set to `True`.
- **image_std** (`Union[float, list[float], tuple[float, ...], NoneType]`) --
  Image standard deviation to use for normalization. Only has an effect if `do_normalize` is set to
  `True`.
- **do_pad** (`bool`, *optional*) --
  Whether to pad the image. Padding is done either to the largest size in the batch
  or to a fixed square size per image. The exact padding strategy depends on the model.
- **pad_size** (`Annotated[Union[int, list[int], tuple[int, ...], dict[str, int], NoneType], None]`) --
  The size in `{"height": int, "width" int}` to pad the images to. Must be larger than any image size
  provided for preprocessing. If `pad_size` is not provided, images will be padded to the largest
  height and width in the batch. Applied only when `do_pad=True.`
- **do_center_crop** (`bool`, *optional*) --
  Whether to center crop the image.
- **data_format** (`Union[~image_utils.ChannelDimension, str, NoneType]`) --
  Only `ChannelDimension.FIRST` is supported. Added for compatibility with slow processors.
- **input_data_format** (`Union[~image_utils.ChannelDimension, str, NoneType]`) --
  The channel dimension format for the input image. If unset, the channel dimension format is inferred
  from the input image. Can be one of:
  - `"channels_first"` or `ChannelDimension.FIRST`: image in (num_channels, height, width) format.
  - `"channels_last"` or `ChannelDimension.LAST`: image in (height, width, num_channels) format.
  - `"none"` or `ChannelDimension.NONE`: image in (height, width) format.
- **device** (`Annotated[Union[str, torch.device, NoneType], None]`) --
  The device to process the images on. If unset, the device is inferred from the input images.
- **return_tensors** (`Annotated[Union[str, ~utils.generic.TensorType, NoneType], None]`) --
  Returns stacked tensors if set to `pt, otherwise returns a list of tensors.
- **disable_grouping** (`bool`, *optional*) --
  Whether to disable grouping of images by size to process them individually and not in batches.
  If None, will be set to True if the images are on CPU, and False otherwise. This choice is based on
  empirical observations, as detailed here: https://github.com/huggingface/transformers/pull/38157
- **image_seq_length** (`int`, *optional*) --
  The number of image tokens to be used for each image in the input.
  Added for backward compatibility but this should be set as a processor attribute in future models.
- **size_divisor** (`.size_divisor`) --
  The size by which to make sure both the height and width can be divided.
- **ignore_index** (`int`, *optional*) --
  Label to be assigned to background pixels in segmentation maps. If provided, segmentation map pixels
  denoted with 0 (background) will be replaced with `ignore_index`.
- **do_reduce_labels** (`bool`, *optional*, defaults to `False`) --
  Whether or not to decrement all label values of segmentation maps by 1. Usually used for datasets where 0
  is used for background, and background itself is not included in all classes of a dataset (e.g. ADE20k).
  The background label will be replaced by `ignore_index`.
- **num_labels** (`int`, *optional*) --
  The number of labels in the segmentation map.0``- **data** (`dict`) -- Dictionary of lists/arrays/tensors returned by the __call__ method ('pixel_values', etc.).
- **tensor_type** (`Union[None, str, TensorType]`, *optional*) -- You can give a tensor_type here to convert the lists of integers in PyTorch/Numpy Tensors at
  initialization.

**Parameters:**

images (`Union[PIL.Image.Image, numpy.ndarray, torch.Tensor, list['PIL.Image.Image'], list[numpy.ndarray], list['torch.Tensor']]`) : Image to preprocess. Expects a single or batch of images with pixel values ranging from 0 to 255. If passing in images with pixel values between 0 and 1, set `do_rescale=False`.

segmentation_maps (`ImageInput`, *optional*) : The segmentation maps.

instance_id_to_semantic_id (`Union[list[dict[int, int]], dict[int, int]]`, *optional*) : A mapping from instance IDs to semantic IDs.

do_convert_rgb (`bool`, *optional*) : Whether to convert the image to RGB.

do_resize (`bool`, *optional*) : Whether to resize the image.

size (`Annotated[Union[int, list[int], tuple[int, ...], dict[str, int], NoneType], None]`) : Describes the maximum input dimensions to the model.

crop_size (`Annotated[Union[int, list[int], tuple[int, ...], dict[str, int], NoneType], None]`) : Size of the output image after applying `center_crop`.

resample (`Annotated[Union[PILImageResampling, int, NoneType], None]`) : Resampling filter to use if resizing the image. This can be one of the enum `PILImageResampling`. Only has an effect if `do_resize` is set to `True`.

do_rescale (`bool`, *optional*) : Whether to rescale the image.

rescale_factor (`float`, *optional*) : Rescale factor to rescale the image by if `do_rescale` is set to `True`.

do_normalize (`bool`, *optional*) : Whether to normalize the image.

image_mean (`Union[float, list[float], tuple[float, ...], NoneType]`) : Image mean to use for normalization. Only has an effect if `do_normalize` is set to `True`.

image_std (`Union[float, list[float], tuple[float, ...], NoneType]`) : Image standard deviation to use for normalization. Only has an effect if `do_normalize` is set to `True`.

do_pad (`bool`, *optional*) : Whether to pad the image. Padding is done either to the largest size in the batch or to a fixed square size per image. The exact padding strategy depends on the model.

pad_size (`Annotated[Union[int, list[int], tuple[int, ...], dict[str, int], NoneType], None]`) : The size in `{"height": int, "width" int}` to pad the images to. Must be larger than any image size provided for preprocessing. If `pad_size` is not provided, images will be padded to the largest height and width in the batch. Applied only when `do_pad=True.`

do_center_crop (`bool`, *optional*) : Whether to center crop the image.

data_format (`Union[~image_utils.ChannelDimension, str, NoneType]`) : Only `ChannelDimension.FIRST` is supported. Added for compatibility with slow processors.

input_data_format (`Union[~image_utils.ChannelDimension, str, NoneType]`) : The channel dimension format for the input image. If unset, the channel dimension format is inferred from the input image. Can be one of: - `"channels_first"` or `ChannelDimension.FIRST`: image in (num_channels, height, width) format. - `"channels_last"` or `ChannelDimension.LAST`: image in (height, width, num_channels) format. - `"none"` or `ChannelDimension.NONE`: image in (height, width) format.

device (`Annotated[Union[str, torch.device, NoneType], None]`) : The device to process the images on. If unset, the device is inferred from the input images.

return_tensors (`Annotated[Union[str, ~utils.generic.TensorType, NoneType], None]`) : Returns stacked tensors if set to `pt, otherwise returns a list of tensors.

disable_grouping (`bool`, *optional*) : Whether to disable grouping of images by size to process them individually and not in batches. If None, will be set to True if the images are on CPU, and False otherwise. This choice is based on empirical observations, as detailed here: https://github.com/huggingface/transformers/pull/38157

image_seq_length (`int`, *optional*) : The number of image tokens to be used for each image in the input. Added for backward compatibility but this should be set as a processor attribute in future models.

size_divisor (`.size_divisor`) : The size by which to make sure both the height and width can be divided.

ignore_index (`int`, *optional*) : Label to be assigned to background pixels in segmentation maps. If provided, segmentation map pixels denoted with 0 (background) will be replaced with `ignore_index`.

do_reduce_labels (`bool`, *optional*, defaults to `False`) : Whether or not to decrement all label values of segmentation maps by 1. Usually used for datasets where 0 is used for background, and background itself is not included in all classes of a dataset (e.g. ADE20k). The background label will be replaced by `ignore_index`.

num_labels (`int`, *optional*) : The number of labels in the segmentation map.

**Returns:**

````

- **data** (`dict`) -- Dictionary of lists/arrays/tensors returned by the __call__ method ('pixel_values', etc.).
- **tensor_type** (`Union[None, str, TensorType]`, *optional*) -- You can give a tensor_type here to convert the lists of integers in PyTorch/Numpy Tensors at
  initialization.
#### post_process_semantic_segmentation[[transformers.Mask2FormerImageProcessorFast.post_process_semantic_segmentation]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/image_processing_mask2former_fast.py#L404)

Converts the output of [Mask2FormerForUniversalSegmentation](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerForUniversalSegmentation) into semantic segmentation maps. Only supports
PyTorch.

**Parameters:**

outputs ([Mask2FormerForUniversalSegmentation](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerForUniversalSegmentation)) : Raw outputs of the model.

target_sizes (`List[Tuple[int, int]]`, *optional*) : List of length (batch_size), where each list item (`Tuple[int, int]]`) corresponds to the requested final size (height, width) of each prediction. If left to None, predictions will not be resized.

**Returns:**

``List[torch.Tensor]``

A list of length `batch_size`, where each item is a semantic segmentation map of shape (height, width)
corresponding to the target_sizes entry (if `target_sizes` is specified). Each entry of each
`torch.Tensor` correspond to a semantic class id.
#### post_process_instance_segmentation[[transformers.Mask2FormerImageProcessorFast.post_process_instance_segmentation]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/image_processing_mask2former_fast.py#L459)

Converts the output of `Mask2FormerForUniversalSegmentationOutput` into instance segmentation predictions.
Only supports PyTorch. If instances could overlap, set either return_coco_annotation or return_binary_maps
to `True` to get the correct segmentation result.

**Parameters:**

outputs ([Mask2FormerForUniversalSegmentation](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerForUniversalSegmentation)) : Raw outputs of the model.

threshold (`float`, *optional*, defaults to 0.5) : The probability score threshold to keep predicted instance masks.

mask_threshold (`float`, *optional*, defaults to 0.5) : Threshold to use when turning the predicted masks into binary values.

overlap_mask_area_threshold (`float`, *optional*, defaults to 0.8) : The overlap mask area threshold to merge or discard small disconnected parts within each binary instance mask.

target_sizes (`List[Tuple]`, *optional*) : List of length (batch_size), where each list item (`Tuple[int, int]]`) corresponds to the requested final size (height, width) of each prediction. If left to None, predictions will not be resized.

return_coco_annotation (`bool`, *optional*, defaults to `False`) : If set to `True`, segmentation maps are returned in COCO run-length encoding (RLE) format.

return_binary_maps (`bool`, *optional*, defaults to `False`) : If set to `True`, segmentation maps are returned as a concatenated tensor of binary segmentation maps (one per detected instance).

**Returns:**

``List[Dict]``

A list of dictionaries, one per image, each dictionary containing two keys:
- **segmentation** -- A tensor of shape `(height, width)` where each pixel represents a `segment_id`, or
  `List[List]` run-length encoding (RLE) of the segmentation map if return_coco_annotation is set to
  `True`, or a tensor of shape `(num_instances, height, width)` if return_binary_maps is set to `True`.
  Set to `None` if no mask if found above `threshold`.
- **segments_info** -- A dictionary that contains additional information on each segment.
  - **id** -- An integer representing the `segment_id`.
  - **label_id** -- An integer representing the label / semantic class id corresponding to `segment_id`.
  - **score** -- Prediction score of segment with `segment_id`.
#### post_process_panoptic_segmentation[[transformers.Mask2FormerImageProcessorFast.post_process_panoptic_segmentation]]

[Source](https://github.com/huggingface/transformers/blob/v5.0.0rc1/src/transformers/models/mask2former/image_processing_mask2former_fast.py#L580)

Converts the output of `Mask2FormerForUniversalSegmentationOutput` into image panoptic segmentation
predictions. Only supports PyTorch.

**Parameters:**

outputs (`Mask2FormerForUniversalSegmentationOutput`) : The outputs from [Mask2FormerForUniversalSegmentation](/docs/transformers/v5.0.0rc1/en/model_doc/mask2former#transformers.Mask2FormerForUniversalSegmentation).

threshold (`float`, *optional*, defaults to 0.5) : The probability score threshold to keep predicted instance masks.

mask_threshold (`float`, *optional*, defaults to 0.5) : Threshold to use when turning the predicted masks into binary values.

overlap_mask_area_threshold (`float`, *optional*, defaults to 0.8) : The overlap mask area threshold to merge or discard small disconnected parts within each binary instance mask.

label_ids_to_fuse (`Set[int]`, *optional*) : The labels in this state will have all their instances be fused together. For instance we could say there can only be one sky in an image, but several persons, so the label ID for sky would be in that set, but not the one for person.

target_sizes (`List[Tuple]`, *optional*) : List of length (batch_size), where each list item (`Tuple[int, int]]`) corresponds to the requested final size (height, width) of each prediction in batch. If left to None, predictions will not be resized.

**Returns:**

``List[Dict]``

A list of dictionaries, one per image, each dictionary containing two keys:
- **segmentation** -- a tensor of shape `(height, width)` where each pixel represents a `segment_id`, set
  to `None` if no mask if found above `threshold`. If `target_sizes` is specified, segmentation is resized
  to the corresponding `target_sizes` entry.
- **segments_info** -- A dictionary that contains additional information on each segment.
  - **id** -- an integer representing the `segment_id`.
  - **label_id** -- An integer representing the label / semantic class id corresponding to `segment_id`.
  - **was_fused** -- a boolean, `True` if `label_id` was in `label_ids_to_fuse`, `False` otherwise.
    Multiple instances of the same class / label were fused and assigned a single `segment_id`.
  - **score** -- Prediction score of segment with `segment_id`.