# coding=utf-8 # Copyright 2022 Apple Inc. and The HuggingFace Inc. team. All rights reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # # Original license: https://github.com/apple/ml-cvnets/blob/main/LICENSE """PyTorch MobileViT model.""" import math from typing import Optional, Union import torch from torch import nn from torch.nn import CrossEntropyLoss from ...activations import ACT2FN from ...modeling_layers import GradientCheckpointingLayer from ...modeling_outputs import ( BaseModelOutputWithNoAttention, BaseModelOutputWithPoolingAndNoAttention, ImageClassifierOutputWithNoAttention, SemanticSegmenterOutput, ) from ...modeling_utils import PreTrainedModel from ...pytorch_utils import find_pruneable_heads_and_indices, prune_linear_layer from ...utils import auto_docstring, logging, torch_int from .configuration_mobilevit import MobileViTConfig logger = logging.get_logger(__name__) def make_divisible(value: int, divisor: int = 8, min_value: Optional[int] = None) -> int: """ Ensure that all layers have a channel count that is divisible by `divisor`. This function is taken from the original TensorFlow repo. It can be seen here: https://github.com/tensorflow/models/blob/master/research/slim/nets/mobilenet/mobilenet.py """ if min_value is None: min_value = divisor new_value = max(min_value, int(value + divisor / 2) // divisor * divisor) # Make sure that round down does not go down by more than 10%. if new_value < 0.9 * value: new_value += divisor return int(new_value) class MobileViTConvLayer(nn.Module): def __init__( self, config: MobileViTConfig, in_channels: int, out_channels: int, kernel_size: int, stride: int = 1, groups: int = 1, bias: bool = False, dilation: int = 1, use_normalization: bool = True, use_activation: Union[bool, str] = True, ) -> None: super().__init__() padding = int((kernel_size - 1) / 2) * dilation if in_channels % groups != 0: raise ValueError(f"Input channels ({in_channels}) are not divisible by {groups} groups.") if out_channels % groups != 0: raise ValueError(f"Output channels ({out_channels}) are not divisible by {groups} groups.") self.convolution = nn.Conv2d( in_channels=in_channels, out_channels=out_channels, kernel_size=kernel_size, stride=stride, padding=padding, dilation=dilation, groups=groups, bias=bias, padding_mode="zeros", ) if use_normalization: self.normalization = nn.BatchNorm2d( num_features=out_channels, eps=1e-5, momentum=0.1, affine=True, track_running_stats=True, ) else: self.normalization = None if use_activation: if isinstance(use_activation, str): self.activation = ACT2FN[use_activation] elif isinstance(config.hidden_act, str): self.activation = ACT2FN[config.hidden_act] else: self.activation = config.hidden_act else: self.activation = None def forward(self, features: torch.Tensor) -> torch.Tensor: features = self.convolution(features) if self.normalization is not None: features = self.normalization(features) if self.activation is not None: features = self.activation(features) return features class MobileViTInvertedResidual(nn.Module): """ Inverted residual block (MobileNetv2): https://huggingface.co/papers/1801.04381 """ def __init__( self, config: MobileViTConfig, in_channels: int, out_channels: int, stride: int, dilation: int = 1 ) -> None: super().__init__() expanded_channels = make_divisible(int(round(in_channels * config.expand_ratio)), 8) if stride not in [1, 2]: raise ValueError(f"Invalid stride {stride}.") self.use_residual = (stride == 1) and (in_channels == out_channels) self.expand_1x1 = MobileViTConvLayer( config, in_channels=in_channels, out_channels=expanded_channels, kernel_size=1 ) self.conv_3x3 = MobileViTConvLayer( config, in_channels=expanded_channels, out_channels=expanded_channels, kernel_size=3, stride=stride, groups=expanded_channels, dilation=dilation, ) self.reduce_1x1 = MobileViTConvLayer( config, in_channels=expanded_channels, out_channels=out_channels, kernel_size=1, use_activation=False, ) def forward(self, features: torch.Tensor) -> torch.Tensor: residual = features features = self.expand_1x1(features) features = self.conv_3x3(features) features = self.reduce_1x1(features) return residual + features if self.use_residual else features class MobileViTMobileNetLayer(nn.Module): def __init__( self, config: MobileViTConfig, in_channels: int, out_channels: int, stride: int = 1, num_stages: int = 1 ) -> None: super().__init__() self.layer = nn.ModuleList() for i in range(num_stages): layer = MobileViTInvertedResidual( config, in_channels=in_channels, out_channels=out_channels, stride=stride if i == 0 else 1, ) self.layer.append(layer) in_channels = out_channels def forward(self, features: torch.Tensor) -> torch.Tensor: for layer_module in self.layer: features = layer_module(features) return features class MobileViTSelfAttention(nn.Module): def __init__(self, config: MobileViTConfig, hidden_size: int) -> None: super().__init__() if hidden_size % config.num_attention_heads != 0: raise ValueError( f"The hidden size {hidden_size} is not a multiple of the number of attention " f"heads {config.num_attention_heads}." ) self.num_attention_heads = config.num_attention_heads self.attention_head_size = int(hidden_size / config.num_attention_heads) self.all_head_size = self.num_attention_heads * self.attention_head_size self.query = nn.Linear(hidden_size, self.all_head_size, bias=config.qkv_bias) self.key = nn.Linear(hidden_size, self.all_head_size, bias=config.qkv_bias) self.value = nn.Linear(hidden_size, self.all_head_size, bias=config.qkv_bias) self.dropout = nn.Dropout(config.attention_probs_dropout_prob) def forward(self, hidden_states: torch.Tensor) -> torch.Tensor: batch_size, seq_length, _ = hidden_states.shape query_layer = ( self.query(hidden_states) .view(batch_size, -1, self.num_attention_heads, self.attention_head_size) .transpose(1, 2) ) key_layer = ( self.key(hidden_states) .view(batch_size, -1, self.num_attention_heads, self.attention_head_size) .transpose(1, 2) ) value_layer = ( self.value(hidden_states) .view(batch_size, -1, self.num_attention_heads, self.attention_head_size) .transpose(1, 2) ) # Take the dot product between "query" and "key" to get the raw attention scores. attention_scores = torch.matmul(query_layer, key_layer.transpose(-1, -2)) attention_scores = attention_scores / math.sqrt(self.attention_head_size) # Normalize the attention scores to probabilities. attention_probs = nn.functional.softmax(attention_scores, dim=-1) # This is actually dropping out entire tokens to attend to, which might # seem a bit unusual, but is taken from the original Transformer paper. attention_probs = self.dropout(attention_probs) context_layer = torch.matmul(attention_probs, value_layer) context_layer = context_layer.permute(0, 2, 1, 3).contiguous() new_context_layer_shape = context_layer.size()[:-2] + (self.all_head_size,) context_layer = context_layer.view(*new_context_layer_shape) return context_layer class MobileViTSelfOutput(nn.Module): def __init__(self, config: MobileViTConfig, hidden_size: int) -> None: super().__init__() self.dense = nn.Linear(hidden_size, hidden_size) self.dropout = nn.Dropout(config.hidden_dropout_prob) def forward(self, hidden_states: torch.Tensor) -> torch.Tensor: hidden_states = self.dense(hidden_states) hidden_states = self.dropout(hidden_states) return hidden_states class MobileViTAttention(nn.Module): def __init__(self, config: MobileViTConfig, hidden_size: int) -> None: super().__init__() self.attention = MobileViTSelfAttention(config, hidden_size) self.output = MobileViTSelfOutput(config, hidden_size) self.pruned_heads = set() def prune_heads(self, heads: set[int]) -> None: if len(heads) == 0: return heads, index = find_pruneable_heads_and_indices( heads, self.attention.num_attention_heads, self.attention.attention_head_size, self.pruned_heads ) # Prune linear layers self.attention.query = prune_linear_layer(self.attention.query, index) self.attention.key = prune_linear_layer(self.attention.key, index) self.attention.value = prune_linear_layer(self.attention.value, index) self.output.dense = prune_linear_layer(self.output.dense, index, dim=1) # Update hyper params and store pruned heads self.attention.num_attention_heads = self.attention.num_attention_heads - len(heads) self.attention.all_head_size = self.attention.attention_head_size * self.attention.num_attention_heads self.pruned_heads = self.pruned_heads.union(heads) def forward(self, hidden_states: torch.Tensor) -> torch.Tensor: self_outputs = self.attention(hidden_states) attention_output = self.output(self_outputs) return attention_output class MobileViTIntermediate(nn.Module): def __init__(self, config: MobileViTConfig, hidden_size: int, intermediate_size: int) -> None: super().__init__() self.dense = nn.Linear(hidden_size, intermediate_size) if isinstance(config.hidden_act, str): self.intermediate_act_fn = ACT2FN[config.hidden_act] else: self.intermediate_act_fn = config.hidden_act def forward(self, hidden_states: torch.Tensor) -> torch.Tensor: hidden_states = self.dense(hidden_states) hidden_states = self.intermediate_act_fn(hidden_states) return hidden_states class MobileViTOutput(nn.Module): def __init__(self, config: MobileViTConfig, hidden_size: int, intermediate_size: int) -> None: super().__init__() self.dense = nn.Linear(intermediate_size, hidden_size) self.dropout = nn.Dropout(config.hidden_dropout_prob) def forward(self, hidden_states: torch.Tensor, input_tensor: torch.Tensor) -> torch.Tensor: hidden_states = self.dense(hidden_states) hidden_states = self.dropout(hidden_states) hidden_states = hidden_states + input_tensor return hidden_states class MobileViTTransformerLayer(nn.Module): def __init__(self, config: MobileViTConfig, hidden_size: int, intermediate_size: int) -> None: super().__init__() self.attention = MobileViTAttention(config, hidden_size) self.intermediate = MobileViTIntermediate(config, hidden_size, intermediate_size) self.output = MobileViTOutput(config, hidden_size, intermediate_size) self.layernorm_before = nn.LayerNorm(hidden_size, eps=config.layer_norm_eps) self.layernorm_after = nn.LayerNorm(hidden_size, eps=config.layer_norm_eps) def forward(self, hidden_states: torch.Tensor) -> torch.Tensor: attention_output = self.attention(self.layernorm_before(hidden_states)) hidden_states = attention_output + hidden_states layer_output = self.layernorm_after(hidden_states) layer_output = self.intermediate(layer_output) layer_output = self.output(layer_output, hidden_states) return layer_output class MobileViTTransformer(nn.Module): def __init__(self, config: MobileViTConfig, hidden_size: int, num_stages: int) -> None: super().__init__() self.layer = nn.ModuleList() for _ in range(num_stages): transformer_layer = MobileViTTransformerLayer( config, hidden_size=hidden_size, intermediate_size=int(hidden_size * config.mlp_ratio), ) self.layer.append(transformer_layer) def forward(self, hidden_states: torch.Tensor) -> torch.Tensor: for layer_module in self.layer: hidden_states = layer_module(hidden_states) return hidden_states class MobileViTLayer(GradientCheckpointingLayer): """ MobileViT block: https://huggingface.co/papers/2110.02178 """ def __init__( self, config: MobileViTConfig, in_channels: int, out_channels: int, stride: int, hidden_size: int, num_stages: int, dilation: int = 1, ) -> None: super().__init__() self.patch_width = config.patch_size self.patch_height = config.patch_size if stride == 2: self.downsampling_layer = MobileViTInvertedResidual( config, in_channels=in_channels, out_channels=out_channels, stride=stride if dilation == 1 else 1, dilation=dilation // 2 if dilation > 1 else 1, ) in_channels = out_channels else: self.downsampling_layer = None self.conv_kxk = MobileViTConvLayer( config, in_channels=in_channels, out_channels=in_channels, kernel_size=config.conv_kernel_size, ) self.conv_1x1 = MobileViTConvLayer( config, in_channels=in_channels, out_channels=hidden_size, kernel_size=1, use_normalization=False, use_activation=False, ) self.transformer = MobileViTTransformer( config, hidden_size=hidden_size, num_stages=num_stages, ) self.layernorm = nn.LayerNorm(hidden_size, eps=config.layer_norm_eps) self.conv_projection = MobileViTConvLayer( config, in_channels=hidden_size, out_channels=in_channels, kernel_size=1 ) self.fusion = MobileViTConvLayer( config, in_channels=2 * in_channels, out_channels=in_channels, kernel_size=config.conv_kernel_size ) def unfolding(self, features: torch.Tensor) -> tuple[torch.Tensor, dict]: patch_width, patch_height = self.patch_width, self.patch_height patch_area = int(patch_width * patch_height) batch_size, channels, orig_height, orig_width = features.shape new_height = ( torch_int(torch.ceil(orig_height / patch_height) * patch_height) if torch.jit.is_tracing() else int(math.ceil(orig_height / patch_height) * patch_height) ) new_width = ( torch_int(torch.ceil(orig_width / patch_width) * patch_width) if torch.jit.is_tracing() else int(math.ceil(orig_width / patch_width) * patch_width) ) interpolate = False if new_width != orig_width or new_height != orig_height: # Note: Padding can be done, but then it needs to be handled in attention function. features = nn.functional.interpolate( features, size=(new_height, new_width), mode="bilinear", align_corners=False ) interpolate = True # number of patches along width and height num_patch_width = new_width // patch_width num_patch_height = new_height // patch_height num_patches = num_patch_height * num_patch_width # convert from shape (batch_size, channels, orig_height, orig_width) # to the shape (batch_size * patch_area, num_patches, channels) patches = features.reshape( batch_size * channels * num_patch_height, patch_height, num_patch_width, patch_width ) patches = patches.transpose(1, 2) patches = patches.reshape(batch_size, channels, num_patches, patch_area) patches = patches.transpose(1, 3) patches = patches.reshape(batch_size * patch_area, num_patches, -1) info_dict = { "orig_size": (orig_height, orig_width), "batch_size": batch_size, "channels": channels, "interpolate": interpolate, "num_patches": num_patches, "num_patches_width": num_patch_width, "num_patches_height": num_patch_height, } return patches, info_dict def folding(self, patches: torch.Tensor, info_dict: dict) -> torch.Tensor: patch_width, patch_height = self.patch_width, self.patch_height patch_area = int(patch_width * patch_height) batch_size = info_dict["batch_size"] channels = info_dict["channels"] num_patches = info_dict["num_patches"] num_patch_height = info_dict["num_patches_height"] num_patch_width = info_dict["num_patches_width"] # convert from shape (batch_size * patch_area, num_patches, channels) # back to shape (batch_size, channels, orig_height, orig_width) features = patches.contiguous().view(batch_size, patch_area, num_patches, -1) features = features.transpose(1, 3) features = features.reshape( batch_size * channels * num_patch_height, num_patch_width, patch_height, patch_width ) features = features.transpose(1, 2) features = features.reshape( batch_size, channels, num_patch_height * patch_height, num_patch_width * patch_width ) if info_dict["interpolate"]: features = nn.functional.interpolate( features, size=info_dict["orig_size"], mode="bilinear", align_corners=False ) return features def forward(self, features: torch.Tensor) -> torch.Tensor: # reduce spatial dimensions if needed if self.downsampling_layer: features = self.downsampling_layer(features) residual = features # local representation features = self.conv_kxk(features) features = self.conv_1x1(features) # convert feature map to patches patches, info_dict = self.unfolding(features) # learn global representations patches = self.transformer(patches) patches = self.layernorm(patches) # convert patches back to feature maps features = self.folding(patches, info_dict) features = self.conv_projection(features) features = self.fusion(torch.cat((residual, features), dim=1)) return features class MobileViTEncoder(nn.Module): def __init__(self, config: MobileViTConfig) -> None: super().__init__() self.config = config self.layer = nn.ModuleList() self.gradient_checkpointing = False # segmentation architectures like DeepLab and PSPNet modify the strides # of the classification backbones dilate_layer_4 = dilate_layer_5 = False if config.output_stride == 8: dilate_layer_4 = True dilate_layer_5 = True elif config.output_stride == 16: dilate_layer_5 = True dilation = 1 layer_1 = MobileViTMobileNetLayer( config, in_channels=config.neck_hidden_sizes[0], out_channels=config.neck_hidden_sizes[1], stride=1, num_stages=1, ) self.layer.append(layer_1) layer_2 = MobileViTMobileNetLayer( config, in_channels=config.neck_hidden_sizes[1], out_channels=config.neck_hidden_sizes[2], stride=2, num_stages=3, ) self.layer.append(layer_2) layer_3 = MobileViTLayer( config, in_channels=config.neck_hidden_sizes[2], out_channels=config.neck_hidden_sizes[3], stride=2, hidden_size=config.hidden_sizes[0], num_stages=2, ) self.layer.append(layer_3) if dilate_layer_4: dilation *= 2 layer_4 = MobileViTLayer( config, in_channels=config.neck_hidden_sizes[3], out_channels=config.neck_hidden_sizes[4], stride=2, hidden_size=config.hidden_sizes[1], num_stages=4, dilation=dilation, ) self.layer.append(layer_4) if dilate_layer_5: dilation *= 2 layer_5 = MobileViTLayer( config, in_channels=config.neck_hidden_sizes[4], out_channels=config.neck_hidden_sizes[5], stride=2, hidden_size=config.hidden_sizes[2], num_stages=3, dilation=dilation, ) self.layer.append(layer_5) def forward( self, hidden_states: torch.Tensor, output_hidden_states: bool = False, return_dict: bool = True, ) -> Union[tuple, BaseModelOutputWithNoAttention]: all_hidden_states = () if output_hidden_states else None for i, layer_module in enumerate(self.layer): hidden_states = layer_module(hidden_states) if output_hidden_states: all_hidden_states = all_hidden_states + (hidden_states,) if not return_dict: return tuple(v for v in [hidden_states, all_hidden_states] if v is not None) return BaseModelOutputWithNoAttention(last_hidden_state=hidden_states, hidden_states=all_hidden_states) @auto_docstring class MobileViTPreTrainedModel(PreTrainedModel): config: MobileViTConfig base_model_prefix = "mobilevit" main_input_name = "pixel_values" supports_gradient_checkpointing = True _no_split_modules = ["MobileViTLayer"] def _init_weights(self, module: nn.Module) -> None: """Initialize the weights""" if isinstance(module, (nn.Linear, nn.Conv2d, nn.BatchNorm2d)): # Slightly different from the TF version which uses truncated_normal for initialization # cf https://github.com/pytorch/pytorch/pull/5617 module.weight.data.normal_(mean=0.0, std=self.config.initializer_range) if module.bias is not None: module.bias.data.zero_() elif isinstance(module, nn.LayerNorm): module.bias.data.zero_() module.weight.data.fill_(1.0) @auto_docstring class MobileViTModel(MobileViTPreTrainedModel): def __init__(self, config: MobileViTConfig, expand_output: bool = True): r""" expand_output (`bool`, *optional*, defaults to `True`): Whether to expand the output of the model using a 1x1 convolution. If `True`, the model will apply an additional 1x1 convolution to expand the output channels from `config.neck_hidden_sizes[5]` to `config.neck_hidden_sizes[6]`. """ super().__init__(config) self.config = config self.expand_output = expand_output self.conv_stem = MobileViTConvLayer( config, in_channels=config.num_channels, out_channels=config.neck_hidden_sizes[0], kernel_size=3, stride=2, ) self.encoder = MobileViTEncoder(config) if self.expand_output: self.conv_1x1_exp = MobileViTConvLayer( config, in_channels=config.neck_hidden_sizes[5], out_channels=config.neck_hidden_sizes[6], kernel_size=1, ) # Initialize weights and apply final processing self.post_init() def _prune_heads(self, heads_to_prune): """Prunes heads of the model. heads_to_prune: dict of {layer_num: list of heads to prune in this layer} See base class PreTrainedModel """ for layer_index, heads in heads_to_prune.items(): mobilevit_layer = self.encoder.layer[layer_index] if isinstance(mobilevit_layer, MobileViTLayer): for transformer_layer in mobilevit_layer.transformer.layer: transformer_layer.attention.prune_heads(heads) @auto_docstring def forward( self, pixel_values: Optional[torch.Tensor] = None, output_hidden_states: Optional[bool] = None, return_dict: Optional[bool] = None, ) -> Union[tuple, BaseModelOutputWithPoolingAndNoAttention]: output_hidden_states = ( output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states ) return_dict = return_dict if return_dict is not None else self.config.use_return_dict if pixel_values is None: raise ValueError("You have to specify pixel_values") embedding_output = self.conv_stem(pixel_values) encoder_outputs = self.encoder( embedding_output, output_hidden_states=output_hidden_states, return_dict=return_dict, ) if self.expand_output: last_hidden_state = self.conv_1x1_exp(encoder_outputs[0]) # global average pooling: (batch_size, channels, height, width) -> (batch_size, channels) pooled_output = torch.mean(last_hidden_state, dim=[-2, -1], keepdim=False) else: last_hidden_state = encoder_outputs[0] pooled_output = None if not return_dict: output = (last_hidden_state, pooled_output) if pooled_output is not None else (last_hidden_state,) return output + encoder_outputs[1:] return BaseModelOutputWithPoolingAndNoAttention( last_hidden_state=last_hidden_state, pooler_output=pooled_output, hidden_states=encoder_outputs.hidden_states, ) @auto_docstring( custom_intro=""" MobileViT model with an image classification head on top (a linear layer on top of the pooled features), e.g. for ImageNet. """ ) class MobileViTForImageClassification(MobileViTPreTrainedModel): def __init__(self, config: MobileViTConfig) -> None: super().__init__(config) self.num_labels = config.num_labels self.mobilevit = MobileViTModel(config) # Classifier head self.dropout = nn.Dropout(config.classifier_dropout_prob, inplace=True) self.classifier = ( nn.Linear(config.neck_hidden_sizes[-1], config.num_labels) if config.num_labels > 0 else nn.Identity() ) # Initialize weights and apply final processing self.post_init() @auto_docstring def forward( self, pixel_values: Optional[torch.Tensor] = None, output_hidden_states: Optional[bool] = None, labels: Optional[torch.Tensor] = None, return_dict: Optional[bool] = None, ) -> Union[tuple, ImageClassifierOutputWithNoAttention]: r""" labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*): Labels for computing the image classification/regression loss. Indices should be in `[0, ..., config.num_labels - 1]`. If `config.num_labels == 1` a regression loss is computed (Mean-Square loss). If `config.num_labels > 1` a classification loss is computed (Cross-Entropy). """ return_dict = return_dict if return_dict is not None else self.config.use_return_dict outputs = self.mobilevit(pixel_values, output_hidden_states=output_hidden_states, return_dict=return_dict) pooled_output = outputs.pooler_output if return_dict else outputs[1] logits = self.classifier(self.dropout(pooled_output)) loss = None if labels is not None: loss = self.loss_function(labels, logits, self.config) if not return_dict: output = (logits,) + outputs[2:] return ((loss,) + output) if loss is not None else output return ImageClassifierOutputWithNoAttention( loss=loss, logits=logits, hidden_states=outputs.hidden_states, ) class MobileViTASPPPooling(nn.Module): def __init__(self, config: MobileViTConfig, in_channels: int, out_channels: int) -> None: super().__init__() self.global_pool = nn.AdaptiveAvgPool2d(output_size=1) self.conv_1x1 = MobileViTConvLayer( config, in_channels=in_channels, out_channels=out_channels, kernel_size=1, stride=1, use_normalization=True, use_activation="relu", ) def forward(self, features: torch.Tensor) -> torch.Tensor: spatial_size = features.shape[-2:] features = self.global_pool(features) features = self.conv_1x1(features) features = nn.functional.interpolate(features, size=spatial_size, mode="bilinear", align_corners=False) return features class MobileViTASPP(nn.Module): """ ASPP module defined in DeepLab papers: https://huggingface.co/papers/1606.00915, https://huggingface.co/papers/1706.05587 """ def __init__(self, config: MobileViTConfig) -> None: super().__init__() in_channels = config.neck_hidden_sizes[-2] out_channels = config.aspp_out_channels if len(config.atrous_rates) != 3: raise ValueError("Expected 3 values for atrous_rates") self.convs = nn.ModuleList() in_projection = MobileViTConvLayer( config, in_channels=in_channels, out_channels=out_channels, kernel_size=1, use_activation="relu", ) self.convs.append(in_projection) self.convs.extend( [ MobileViTConvLayer( config, in_channels=in_channels, out_channels=out_channels, kernel_size=3, dilation=rate, use_activation="relu", ) for rate in config.atrous_rates ] ) pool_layer = MobileViTASPPPooling(config, in_channels, out_channels) self.convs.append(pool_layer) self.project = MobileViTConvLayer( config, in_channels=5 * out_channels, out_channels=out_channels, kernel_size=1, use_activation="relu" ) self.dropout = nn.Dropout(p=config.aspp_dropout_prob) def forward(self, features: torch.Tensor) -> torch.Tensor: pyramid = [] for conv in self.convs: pyramid.append(conv(features)) pyramid = torch.cat(pyramid, dim=1) pooled_features = self.project(pyramid) pooled_features = self.dropout(pooled_features) return pooled_features class MobileViTDeepLabV3(nn.Module): """ DeepLabv3 architecture: https://huggingface.co/papers/1706.05587 """ def __init__(self, config: MobileViTConfig) -> None: super().__init__() self.aspp = MobileViTASPP(config) self.dropout = nn.Dropout2d(config.classifier_dropout_prob) self.classifier = MobileViTConvLayer( config, in_channels=config.aspp_out_channels, out_channels=config.num_labels, kernel_size=1, use_normalization=False, use_activation=False, bias=True, ) def forward(self, hidden_states: torch.Tensor) -> torch.Tensor: features = self.aspp(hidden_states[-1]) features = self.dropout(features) features = self.classifier(features) return features @auto_docstring( custom_intro=""" MobileViT model with a semantic segmentation head on top, e.g. for Pascal VOC. """ ) class MobileViTForSemanticSegmentation(MobileViTPreTrainedModel): def __init__(self, config: MobileViTConfig) -> None: super().__init__(config) self.num_labels = config.num_labels self.mobilevit = MobileViTModel(config, expand_output=False) self.segmentation_head = MobileViTDeepLabV3(config) # Initialize weights and apply final processing self.post_init() @auto_docstring def forward( self, pixel_values: Optional[torch.Tensor] = None, labels: Optional[torch.Tensor] = None, output_hidden_states: Optional[bool] = None, return_dict: Optional[bool] = None, ) -> Union[tuple, SemanticSegmenterOutput]: r""" labels (`torch.LongTensor` of shape `(batch_size, height, width)`, *optional*): Ground truth semantic segmentation maps for computing the loss. Indices should be in `[0, ..., config.num_labels - 1]`. If `config.num_labels > 1`, a classification loss is computed (Cross-Entropy). Examples: ```python >>> import requests >>> import torch >>> from PIL import Image >>> from transformers import AutoImageProcessor, MobileViTForSemanticSegmentation >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg" >>> image = Image.open(requests.get(url, stream=True).raw) >>> image_processor = AutoImageProcessor.from_pretrained("apple/deeplabv3-mobilevit-small") >>> model = MobileViTForSemanticSegmentation.from_pretrained("apple/deeplabv3-mobilevit-small") >>> inputs = image_processor(images=image, return_tensors="pt") >>> with torch.no_grad(): ... outputs = model(**inputs) >>> # logits are of shape (batch_size, num_labels, height, width) >>> logits = outputs.logits ```""" output_hidden_states = ( output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states ) return_dict = return_dict if return_dict is not None else self.config.use_return_dict if labels is not None and self.config.num_labels == 1: raise ValueError("The number of labels should be greater than one") outputs = self.mobilevit( pixel_values, output_hidden_states=True, # we need the intermediate hidden states return_dict=return_dict, ) encoder_hidden_states = outputs.hidden_states if return_dict else outputs[1] logits = self.segmentation_head(encoder_hidden_states) loss = None if labels is not None: # upsample logits to the images' original size upsampled_logits = nn.functional.interpolate( logits, size=labels.shape[-2:], mode="bilinear", align_corners=False ) loss_fct = CrossEntropyLoss(ignore_index=self.config.semantic_loss_ignore_index) loss = loss_fct(upsampled_logits, labels) if not return_dict: if output_hidden_states: output = (logits,) + outputs[1:] else: output = (logits,) + outputs[2:] return ((loss,) + output) if loss is not None else output return SemanticSegmenterOutput( loss=loss, logits=logits, hidden_states=outputs.hidden_states if output_hidden_states else None, attentions=None, ) __all__ = [ "MobileViTForImageClassification", "MobileViTForSemanticSegmentation", "MobileViTModel", "MobileViTPreTrainedModel", ]