Enable multi-label image classification in pipeline (#28433)

Enable multi-label image classification
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amyeroberts 2024-01-11 10:29:38 +00:00 committed by GitHub
parent 8205b2647c
commit 66964c00f6
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2 changed files with 133 additions and 18 deletions

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@ -1,6 +1,9 @@
from typing import List, Union
import numpy as np
from ..utils import (
ExplicitEnum,
add_end_docstrings,
is_tf_available,
is_torch_available,
@ -17,10 +20,7 @@ if is_vision_available():
from ..image_utils import load_image
if is_tf_available():
import tensorflow as tf
from ..models.auto.modeling_tf_auto import TF_MODEL_FOR_IMAGE_CLASSIFICATION_MAPPING_NAMES
from ..tf_utils import stable_softmax
if is_torch_available():
from ..models.auto.modeling_auto import MODEL_FOR_IMAGE_CLASSIFICATION_MAPPING_NAMES
@ -28,7 +28,38 @@ if is_torch_available():
logger = logging.get_logger(__name__)
@add_end_docstrings(PIPELINE_INIT_ARGS)
# Copied from transformers.pipelines.text_classification.sigmoid
def sigmoid(_outputs):
return 1.0 / (1.0 + np.exp(-_outputs))
# Copied from transformers.pipelines.text_classification.softmax
def softmax(_outputs):
maxes = np.max(_outputs, axis=-1, keepdims=True)
shifted_exp = np.exp(_outputs - maxes)
return shifted_exp / shifted_exp.sum(axis=-1, keepdims=True)
# Copied from transformers.pipelines.text_classification.ClassificationFunction
class ClassificationFunction(ExplicitEnum):
SIGMOID = "sigmoid"
SOFTMAX = "softmax"
NONE = "none"
@add_end_docstrings(
PIPELINE_INIT_ARGS,
r"""
function_to_apply (`str`, *optional*, defaults to `"default"`):
The function to apply to the model outputs in order to retrieve the scores. Accepts four different values:
- `"default"`: if the model has a single label, will apply the sigmoid function on the output. If the model
has several labels, will apply the softmax function on the output.
- `"sigmoid"`: Applies the sigmoid function on the output.
- `"softmax"`: Applies the softmax function on the output.
- `"none"`: Does not apply any function on the output.
""",
)
class ImageClassificationPipeline(Pipeline):
"""
Image classification pipeline using any `AutoModelForImageClassification`. This pipeline predicts the class of an
@ -53,6 +84,8 @@ class ImageClassificationPipeline(Pipeline):
[huggingface.co/models](https://huggingface.co/models?filter=image-classification).
"""
function_to_apply: ClassificationFunction = ClassificationFunction.NONE
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
requires_backends(self, "vision")
@ -62,13 +95,17 @@ class ImageClassificationPipeline(Pipeline):
else MODEL_FOR_IMAGE_CLASSIFICATION_MAPPING_NAMES
)
def _sanitize_parameters(self, top_k=None, timeout=None):
def _sanitize_parameters(self, top_k=None, function_to_apply=None, timeout=None):
preprocess_params = {}
if timeout is not None:
preprocess_params["timeout"] = timeout
postprocess_params = {}
if top_k is not None:
postprocess_params["top_k"] = top_k
if isinstance(function_to_apply, str):
function_to_apply = ClassificationFunction(function_to_apply.lower())
if function_to_apply is not None:
postprocess_params["function_to_apply"] = function_to_apply
return preprocess_params, {}, postprocess_params
def __call__(self, images: Union[str, List[str], "Image.Image", List["Image.Image"]], **kwargs):
@ -86,6 +123,21 @@ class ImageClassificationPipeline(Pipeline):
The pipeline accepts either a single image or a batch of images, which must then be passed as a string.
Images in a batch must all be in the same format: all as http links, all as local paths, or all as PIL
images.
function_to_apply (`str`, *optional*, defaults to `"default"`):
The function to apply to the model outputs in order to retrieve the scores. Accepts four different
values:
If this argument is not specified, then it will apply the following functions according to the number
of labels:
- If the model has a single label, will apply the sigmoid function on the output.
- If the model has several labels, will apply the softmax function on the output.
Possible values are:
- `"sigmoid"`: Applies the sigmoid function on the output.
- `"softmax"`: Applies the softmax function on the output.
- `"none"`: Does not apply any function on the output.
top_k (`int`, *optional*, defaults to 5):
The number of top labels that will be returned by the pipeline. If the provided number is higher than
the number of labels available in the model configuration, it will default to the number of labels.
@ -114,20 +166,37 @@ class ImageClassificationPipeline(Pipeline):
model_outputs = self.model(**model_inputs)
return model_outputs
def postprocess(self, model_outputs, top_k=5):
def postprocess(self, model_outputs, function_to_apply=None, top_k=5):
if function_to_apply is None:
if self.model.config.problem_type == "multi_label_classification" or self.model.config.num_labels == 1:
function_to_apply = ClassificationFunction.SIGMOID
elif self.model.config.problem_type == "single_label_classification" or self.model.config.num_labels > 1:
function_to_apply = ClassificationFunction.SOFTMAX
elif hasattr(self.model.config, "function_to_apply") and function_to_apply is None:
function_to_apply = self.model.config.function_to_apply
else:
function_to_apply = ClassificationFunction.NONE
if top_k > self.model.config.num_labels:
top_k = self.model.config.num_labels
if self.framework == "pt":
probs = model_outputs.logits.softmax(-1)[0]
scores, ids = probs.topk(top_k)
elif self.framework == "tf":
probs = stable_softmax(model_outputs.logits, axis=-1)[0]
topk = tf.math.top_k(probs, k=top_k)
scores, ids = topk.values.numpy(), topk.indices.numpy()
else:
raise ValueError(f"Unsupported framework: {self.framework}")
outputs = model_outputs["logits"][0]
outputs = outputs.numpy()
scores = scores.tolist()
ids = ids.tolist()
return [{"score": score, "label": self.model.config.id2label[_id]} for score, _id in zip(scores, ids)]
if function_to_apply == ClassificationFunction.SIGMOID:
scores = sigmoid(outputs)
elif function_to_apply == ClassificationFunction.SOFTMAX:
scores = softmax(outputs)
elif function_to_apply == ClassificationFunction.NONE:
scores = outputs
else:
raise ValueError(f"Unrecognized `function_to_apply` argument: {function_to_apply}")
dict_scores = [
{"label": self.model.config.id2label[i], "score": score.item()} for i, score in enumerate(scores)
]
dict_scores.sort(key=lambda x: x["score"], reverse=True)
if top_k is not None:
dict_scores = dict_scores[:top_k]
return dict_scores

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@ -221,3 +221,49 @@ class ImageClassificationPipelineTests(unittest.TestCase):
{"score": 0.0096, "label": "quilt, comforter, comfort, puff"},
],
)
@slow
@require_torch
def test_multilabel_classification(self):
small_model = "hf-internal-testing/tiny-random-vit"
# Sigmoid is applied for multi-label classification
image_classifier = pipeline("image-classification", model=small_model)
image_classifier.model.config.problem_type = "multi_label_classification"
outputs = image_classifier("http://images.cocodataset.org/val2017/000000039769.jpg")
self.assertEqual(
nested_simplify(outputs, decimals=4),
[{"label": "LABEL_1", "score": 0.5356}, {"label": "LABEL_0", "score": 0.4612}],
)
outputs = image_classifier(
[
"http://images.cocodataset.org/val2017/000000039769.jpg",
"http://images.cocodataset.org/val2017/000000039769.jpg",
]
)
self.assertEqual(
nested_simplify(outputs, decimals=4),
[
[{"label": "LABEL_1", "score": 0.5356}, {"label": "LABEL_0", "score": 0.4612}],
[{"label": "LABEL_1", "score": 0.5356}, {"label": "LABEL_0", "score": 0.4612}],
],
)
@slow
@require_torch
def test_function_to_apply(self):
small_model = "hf-internal-testing/tiny-random-vit"
# Sigmoid is applied for multi-label classification
image_classifier = pipeline("image-classification", model=small_model)
outputs = image_classifier(
"http://images.cocodataset.org/val2017/000000039769.jpg",
function_to_apply="sigmoid",
)
self.assertEqual(
nested_simplify(outputs, decimals=4),
[{"label": "LABEL_1", "score": 0.5356}, {"label": "LABEL_0", "score": 0.4612}],
)