configuration_resnet.py

# coding=utf-8
# Copyright 2022 Microsoft Research, Inc. and The HuggingFace Inc. team. All rights reserved.
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# Licensed under the Apache License, Version 2.0 (the "License");
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#     http://www.apache.org/licenses/LICENSE-2.0
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""" ResNet model configuration"""

from collections import OrderedDict
from typing import Mapping

from packaging import version

from ...configuration_utils import PretrainedConfig
from ...onnx import OnnxConfig
from ...utils import logging
from ...utils.backbone_utils import BackboneConfigMixin, get_aligned_output_features_output_indices


logger = logging.get_logger(__name__)

RESNET_PRETRAINED_CONFIG_ARCHIVE_MAP = {
    "microsoft/resnet-50": "https://huggingface.co/microsoft/resnet-50/blob/main/config.json",
}


class ResNetConfig(BackboneConfigMixin, PretrainedConfig):
    r"""
    This is the configuration class to store the configuration of a [`ResNetModel`]. It is used to instantiate an
    ResNet 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 ResNet
    [microsoft/resnet-50](https://huggingface.co/microsoft/resnet-50) architecture.

    Configuration objects inherit from [`PretrainedConfig`] and can be used to control the model outputs. Read the
    documentation from [`PretrainedConfig`] for more information.

    Args:
        num_channels (`int`, *optional*, defaults to 3):
            The number of input channels.
        embedding_size (`int`, *optional*, defaults to 64):
            Dimensionality (hidden size) for the embedding layer.
        hidden_sizes (`List[int]`, *optional*, defaults to `[256, 512, 1024, 2048]`):
            Dimensionality (hidden size) at each stage.
        depths (`List[int]`, *optional*, defaults to `[3, 4, 6, 3]`):
            Depth (number of layers) for each stage.
        layer_type (`str`, *optional*, defaults to `"bottleneck"`):
            The layer to use, it can be either `"basic"` (used for smaller models, like resnet-18 or resnet-34) or
            `"bottleneck"` (used for larger models like resnet-50 and above).
        hidden_act (`str`, *optional*, defaults to `"relu"`):
            The non-linear activation function in each block. If string, `"gelu"`, `"relu"`, `"selu"` and `"gelu_new"`
            are supported.
        downsample_in_first_stage (`bool`, *optional*, defaults to `False`):
            If `True`, the first stage will downsample the inputs using a `stride` of 2.
        out_features (`List[str]`, *optional*):
            If used as backbone, list of features to output. Can be any of `"stem"`, `"stage1"`, `"stage2"`, etc.
            (depending on how many stages the model has). If unset and `out_indices` is set, will default to the
            corresponding stages. If unset and `out_indices` is unset, will default to the last stage.
        out_indices (`List[int]`, *optional*):
            If used as backbone, list of indices of features to output. Can be any of 0, 1, 2, etc. (depending on how
            many stages the model has). If unset and `out_features` is set, will default to the corresponding stages.
            If unset and `out_features` is unset, will default to the last stage.

    Example:
    ```python
    >>> from transformers import ResNetConfig, ResNetModel

    >>> # Initializing a ResNet resnet-50 style configuration
    >>> configuration = ResNetConfig()

    >>> # Initializing a model (with random weights) from the resnet-50 style configuration
    >>> model = ResNetModel(configuration)

    >>> # Accessing the model configuration
    >>> configuration = model.config
    ```
    """
    model_type = "resnet"
    layer_types = ["basic", "bottleneck"]

    def __init__(
        self,
        num_channels=3,
        embedding_size=64,
        hidden_sizes=[256, 512, 1024, 2048],
        depths=[3, 4, 6, 3],
        layer_type="bottleneck",
        hidden_act="relu",
        downsample_in_first_stage=False,
        out_features=None,
        out_indices=None,
        **kwargs,
    ):
        super().__init__(**kwargs)
        if layer_type not in self.layer_types:
            raise ValueError(f"layer_type={layer_type} is not one of {','.join(self.layer_types)}")
        self.num_channels = num_channels
        self.embedding_size = embedding_size
        self.hidden_sizes = hidden_sizes
        self.depths = depths
        self.layer_type = layer_type
        self.hidden_act = hidden_act
        self.downsample_in_first_stage = downsample_in_first_stage
        self.stage_names = ["stem"] + [f"stage{idx}" for idx in range(1, len(depths) + 1)]
        self._out_features, self._out_indices = get_aligned_output_features_output_indices(
            out_features=out_features, out_indices=out_indices, stage_names=self.stage_names
        )


class ResNetOnnxConfig(OnnxConfig):
    torch_onnx_minimum_version = version.parse("1.11")

    @property
    def inputs(self) -> Mapping[str, Mapping[int, str]]:
        return OrderedDict(
            [
                ("pixel_values", {0: "batch", 1: "num_channels", 2: "height", 3: "width"}),
            ]
        )

    @property
    def atol_for_validation(self) -> float:
        return 1e-3