# coding=utf-8 # Copyright 2021 HuggingFace Inc. # # 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. import os import tempfile import unittest import datasets import numpy as np import pytest from huggingface_hub.file_download import http_get from requests import ConnectTimeout, ReadTimeout from tests.pipelines.test_pipelines_document_question_answering import INVOICE_URL from transformers import is_torch_available, is_vision_available from transformers.image_utils import ChannelDimension, get_channel_dimension_axis, make_list_of_images from transformers.testing_utils import is_flaky, require_torch, require_vision if is_torch_available(): import torch if is_vision_available(): import PIL.Image from transformers import ImageFeatureExtractionMixin from transformers.image_utils import get_image_size, infer_channel_dimension_format, load_image def get_random_image(height, width): random_array = np.random.randint(0, 256, (height, width, 3), dtype=np.uint8) return PIL.Image.fromarray(random_array) @require_vision class ImageFeatureExtractionTester(unittest.TestCase): def test_conversion_image_to_array(self): feature_extractor = ImageFeatureExtractionMixin() image = get_random_image(16, 32) # Conversion with defaults (rescale + channel first) array1 = feature_extractor.to_numpy_array(image) self.assertTrue(array1.dtype, np.float32) self.assertEqual(array1.shape, (3, 16, 32)) # Conversion with rescale and not channel first array2 = feature_extractor.to_numpy_array(image, channel_first=False) self.assertTrue(array2.dtype, np.float32) self.assertEqual(array2.shape, (16, 32, 3)) self.assertTrue(np.array_equal(array1, array2.transpose(2, 0, 1))) # Conversion with no rescale and channel first array3 = feature_extractor.to_numpy_array(image, rescale=False) self.assertTrue(array3.dtype, np.uint8) self.assertEqual(array3.shape, (3, 16, 32)) self.assertTrue(np.array_equal(array1, array3.astype(np.float32) * (1 / 255.0))) # Conversion with no rescale and not channel first array4 = feature_extractor.to_numpy_array(image, rescale=False, channel_first=False) self.assertTrue(array4.dtype, np.uint8) self.assertEqual(array4.shape, (16, 32, 3)) self.assertTrue(np.array_equal(array2, array4.astype(np.float32) * (1 / 255.0))) def test_conversion_array_to_array(self): feature_extractor = ImageFeatureExtractionMixin() array = np.random.randint(0, 256, (16, 32, 3), dtype=np.uint8) # By default, rescale (for an array of ints) and channel permute array1 = feature_extractor.to_numpy_array(array) self.assertTrue(array1.dtype, np.float32) self.assertEqual(array1.shape, (3, 16, 32)) self.assertTrue(np.array_equal(array1, array.transpose(2, 0, 1).astype(np.float32) * (1 / 255.0))) # Same with no permute array2 = feature_extractor.to_numpy_array(array, channel_first=False) self.assertTrue(array2.dtype, np.float32) self.assertEqual(array2.shape, (16, 32, 3)) self.assertTrue(np.array_equal(array2, array.astype(np.float32) * (1 / 255.0))) # Force rescale to False array3 = feature_extractor.to_numpy_array(array, rescale=False) self.assertTrue(array3.dtype, np.uint8) self.assertEqual(array3.shape, (3, 16, 32)) self.assertTrue(np.array_equal(array3, array.transpose(2, 0, 1))) # Force rescale to False and no channel permute array4 = feature_extractor.to_numpy_array(array, rescale=False, channel_first=False) self.assertTrue(array4.dtype, np.uint8) self.assertEqual(array4.shape, (16, 32, 3)) self.assertTrue(np.array_equal(array4, array)) # Now test the default rescale for a float array (defaults to False) array5 = feature_extractor.to_numpy_array(array2) self.assertTrue(array5.dtype, np.float32) self.assertEqual(array5.shape, (3, 16, 32)) self.assertTrue(np.array_equal(array5, array1)) def test_make_list_of_images_numpy(self): # Test a single image is converted to a list of 1 image images = np.random.randint(0, 256, (16, 32, 3)) images_list = make_list_of_images(images) self.assertEqual(len(images_list), 1) self.assertTrue(np.array_equal(images_list[0], images)) self.assertIsInstance(images_list, list) # Test a batch of images is converted to a list of images images = np.random.randint(0, 256, (4, 16, 32, 3)) images_list = make_list_of_images(images) self.assertEqual(len(images_list), 4) self.assertTrue(np.array_equal(images_list[0], images[0])) self.assertIsInstance(images_list, list) # Test a list of images is not modified images = [np.random.randint(0, 256, (16, 32, 3)) for _ in range(4)] images_list = make_list_of_images(images) self.assertEqual(len(images_list), 4) self.assertTrue(np.array_equal(images_list[0], images[0])) self.assertIsInstance(images_list, list) # Test batched masks with no channel dimension are converted to a list of masks masks = np.random.randint(0, 2, (4, 16, 32)) masks_list = make_list_of_images(masks, expected_ndims=2) self.assertEqual(len(masks_list), 4) self.assertTrue(np.array_equal(masks_list[0], masks[0])) self.assertIsInstance(masks_list, list) @require_torch def test_make_list_of_images_torch(self): # Test a single image is converted to a list of 1 image images = torch.randint(0, 256, (16, 32, 3)) images_list = make_list_of_images(images) self.assertEqual(len(images_list), 1) self.assertTrue(np.array_equal(images_list[0], images)) self.assertIsInstance(images_list, list) # Test a batch of images is converted to a list of images images = torch.randint(0, 256, (4, 16, 32, 3)) images_list = make_list_of_images(images) self.assertEqual(len(images_list), 4) self.assertTrue(np.array_equal(images_list[0], images[0])) self.assertIsInstance(images_list, list) # Test a list of images is left unchanged images = [torch.randint(0, 256, (16, 32, 3)) for _ in range(4)] images_list = make_list_of_images(images) self.assertEqual(len(images_list), 4) self.assertTrue(np.array_equal(images_list[0], images[0])) self.assertIsInstance(images_list, list) @require_torch def test_conversion_torch_to_array(self): feature_extractor = ImageFeatureExtractionMixin() tensor = torch.randint(0, 256, (16, 32, 3)) array = tensor.numpy() # By default, rescale (for a tensor of ints) and channel permute array1 = feature_extractor.to_numpy_array(array) self.assertTrue(array1.dtype, np.float32) self.assertEqual(array1.shape, (3, 16, 32)) self.assertTrue(np.array_equal(array1, array.transpose(2, 0, 1).astype(np.float32) * (1 / 255.0))) # Same with no permute array2 = feature_extractor.to_numpy_array(array, channel_first=False) self.assertTrue(array2.dtype, np.float32) self.assertEqual(array2.shape, (16, 32, 3)) self.assertTrue(np.array_equal(array2, array.astype(np.float32) * (1 / 255.0))) # Force rescale to False array3 = feature_extractor.to_numpy_array(array, rescale=False) self.assertTrue(array3.dtype, np.uint8) self.assertEqual(array3.shape, (3, 16, 32)) self.assertTrue(np.array_equal(array3, array.transpose(2, 0, 1))) # Force rescale to False and no channel permute array4 = feature_extractor.to_numpy_array(array, rescale=False, channel_first=False) self.assertTrue(array4.dtype, np.uint8) self.assertEqual(array4.shape, (16, 32, 3)) self.assertTrue(np.array_equal(array4, array)) # Now test the default rescale for a float tensor (defaults to False) array5 = feature_extractor.to_numpy_array(array2) self.assertTrue(array5.dtype, np.float32) self.assertEqual(array5.shape, (3, 16, 32)) self.assertTrue(np.array_equal(array5, array1)) def test_conversion_image_to_image(self): feature_extractor = ImageFeatureExtractionMixin() image = get_random_image(16, 32) # On an image, `to_pil_image1` is a noop. image1 = feature_extractor.to_pil_image(image) self.assertTrue(isinstance(image, PIL.Image.Image)) self.assertTrue(np.array_equal(np.array(image), np.array(image1))) def test_conversion_array_to_image(self): feature_extractor = ImageFeatureExtractionMixin() array = np.random.randint(0, 256, (16, 32, 3), dtype=np.uint8) # By default, no rescale (for an array of ints) image1 = feature_extractor.to_pil_image(array) self.assertTrue(isinstance(image1, PIL.Image.Image)) self.assertTrue(np.array_equal(np.array(image1), array)) # If the array is channel-first, proper reordering of the channels is done. image2 = feature_extractor.to_pil_image(array.transpose(2, 0, 1)) self.assertTrue(isinstance(image2, PIL.Image.Image)) self.assertTrue(np.array_equal(np.array(image2), array)) # If the array has floating type, it's rescaled by default. image3 = feature_extractor.to_pil_image(array.astype(np.float32) * (1 / 255.0)) self.assertTrue(isinstance(image3, PIL.Image.Image)) self.assertTrue(np.array_equal(np.array(image3), array)) # You can override the default to rescale. image4 = feature_extractor.to_pil_image(array.astype(np.float32), rescale=False) self.assertTrue(isinstance(image4, PIL.Image.Image)) self.assertTrue(np.array_equal(np.array(image4), array)) # And with floats + channel first. image5 = feature_extractor.to_pil_image(array.transpose(2, 0, 1).astype(np.float32) * (1 / 255.0)) self.assertTrue(isinstance(image5, PIL.Image.Image)) self.assertTrue(np.array_equal(np.array(image5), array)) @require_torch def test_conversion_tensor_to_image(self): feature_extractor = ImageFeatureExtractionMixin() tensor = torch.randint(0, 256, (16, 32, 3)) array = tensor.numpy() # By default, no rescale (for a tensor of ints) image1 = feature_extractor.to_pil_image(tensor) self.assertTrue(isinstance(image1, PIL.Image.Image)) self.assertTrue(np.array_equal(np.array(image1), array)) # If the tensor is channel-first, proper reordering of the channels is done. image2 = feature_extractor.to_pil_image(tensor.permute(2, 0, 1)) self.assertTrue(isinstance(image2, PIL.Image.Image)) self.assertTrue(np.array_equal(np.array(image2), array)) # If the tensor has floating type, it's rescaled by default. image3 = feature_extractor.to_pil_image(tensor.float() / 255.0) self.assertTrue(isinstance(image3, PIL.Image.Image)) self.assertTrue(np.array_equal(np.array(image3), array)) # You can override the default to rescale. image4 = feature_extractor.to_pil_image(tensor.float(), rescale=False) self.assertTrue(isinstance(image4, PIL.Image.Image)) self.assertTrue(np.array_equal(np.array(image4), array)) # And with floats + channel first. image5 = feature_extractor.to_pil_image(tensor.permute(2, 0, 1).float() * (1 / 255.0)) self.assertTrue(isinstance(image5, PIL.Image.Image)) self.assertTrue(np.array_equal(np.array(image5), array)) def test_resize_image_and_array(self): feature_extractor = ImageFeatureExtractionMixin() image = get_random_image(16, 32) array = np.array(image) # Size can be an int or a tuple of ints. resized_image = feature_extractor.resize(image, 8) self.assertTrue(isinstance(resized_image, PIL.Image.Image)) self.assertEqual(resized_image.size, (8, 8)) resized_image1 = feature_extractor.resize(image, (8, 16)) self.assertTrue(isinstance(resized_image1, PIL.Image.Image)) self.assertEqual(resized_image1.size, (8, 16)) # Passing an array converts it to a PIL Image. resized_image2 = feature_extractor.resize(array, 8) self.assertTrue(isinstance(resized_image2, PIL.Image.Image)) self.assertEqual(resized_image2.size, (8, 8)) self.assertTrue(np.array_equal(np.array(resized_image), np.array(resized_image2))) resized_image3 = feature_extractor.resize(image, (8, 16)) self.assertTrue(isinstance(resized_image3, PIL.Image.Image)) self.assertEqual(resized_image3.size, (8, 16)) self.assertTrue(np.array_equal(np.array(resized_image1), np.array(resized_image3))) def test_resize_image_and_array_non_default_to_square(self): feature_extractor = ImageFeatureExtractionMixin() heights_widths = [ # height, width # square image (28, 28), (27, 27), # rectangular image: h < w (28, 34), (29, 35), # rectangular image: h > w (34, 28), (35, 29), ] # single integer or single integer in tuple/list sizes = [22, 27, 28, 36, [22], (27,)] for (height, width), size in zip(heights_widths, sizes): for max_size in (None, 37, 1000): image = get_random_image(height, width) array = np.array(image) size = size[0] if isinstance(size, (list, tuple)) else size # Size can be an int or a tuple of ints. # 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). if height < width: exp_w, exp_h = (int(size * width / height), size) if max_size is not None and max_size < exp_w: exp_w, exp_h = max_size, int(max_size * exp_h / exp_w) elif width < height: exp_w, exp_h = (size, int(size * height / width)) if max_size is not None and max_size < exp_h: exp_w, exp_h = int(max_size * exp_w / exp_h), max_size else: exp_w, exp_h = (size, size) if max_size is not None and max_size < size: exp_w, exp_h = max_size, max_size resized_image = feature_extractor.resize(image, size=size, default_to_square=False, max_size=max_size) self.assertTrue(isinstance(resized_image, PIL.Image.Image)) self.assertEqual(resized_image.size, (exp_w, exp_h)) # Passing an array converts it to a PIL Image. resized_image2 = feature_extractor.resize(array, size=size, default_to_square=False, max_size=max_size) self.assertTrue(isinstance(resized_image2, PIL.Image.Image)) self.assertEqual(resized_image2.size, (exp_w, exp_h)) self.assertTrue(np.array_equal(np.array(resized_image), np.array(resized_image2))) @require_torch def test_resize_tensor(self): feature_extractor = ImageFeatureExtractionMixin() tensor = torch.randint(0, 256, (16, 32, 3)) array = tensor.numpy() # Size can be an int or a tuple of ints. resized_image = feature_extractor.resize(tensor, 8) self.assertTrue(isinstance(resized_image, PIL.Image.Image)) self.assertEqual(resized_image.size, (8, 8)) resized_image1 = feature_extractor.resize(tensor, (8, 16)) self.assertTrue(isinstance(resized_image1, PIL.Image.Image)) self.assertEqual(resized_image1.size, (8, 16)) # Check we get the same results as with NumPy arrays. resized_image2 = feature_extractor.resize(array, 8) self.assertTrue(np.array_equal(np.array(resized_image), np.array(resized_image2))) resized_image3 = feature_extractor.resize(array, (8, 16)) self.assertTrue(np.array_equal(np.array(resized_image1), np.array(resized_image3))) def test_normalize_image(self): feature_extractor = ImageFeatureExtractionMixin() image = get_random_image(16, 32) array = np.array(image) mean = [0.1, 0.5, 0.9] std = [0.2, 0.4, 0.6] # PIL Image are converted to NumPy arrays for the normalization normalized_image = feature_extractor.normalize(image, mean, std) self.assertTrue(isinstance(normalized_image, np.ndarray)) self.assertEqual(normalized_image.shape, (3, 16, 32)) # During the conversion rescale and channel first will be applied. expected = array.transpose(2, 0, 1).astype(np.float32) * (1 / 255.0) np_mean = np.array(mean).astype(np.float32)[:, None, None] np_std = np.array(std).astype(np.float32)[:, None, None] expected = (expected - np_mean) / np_std self.assertTrue(np.array_equal(normalized_image, expected)) def test_normalize_array(self): feature_extractor = ImageFeatureExtractionMixin() array = np.random.random((16, 32, 3)) mean = [0.1, 0.5, 0.9] std = [0.2, 0.4, 0.6] # mean and std can be passed as lists or NumPy arrays. expected = (array - np.array(mean)) / np.array(std) normalized_array = feature_extractor.normalize(array, mean, std) self.assertTrue(np.array_equal(normalized_array, expected)) normalized_array = feature_extractor.normalize(array, np.array(mean), np.array(std)) self.assertTrue(np.array_equal(normalized_array, expected)) # Normalize will detect automatically if channel first or channel last is used. array = np.random.random((3, 16, 32)) expected = (array - np.array(mean)[:, None, None]) / np.array(std)[:, None, None] normalized_array = feature_extractor.normalize(array, mean, std) self.assertTrue(np.array_equal(normalized_array, expected)) normalized_array = feature_extractor.normalize(array, np.array(mean), np.array(std)) self.assertTrue(np.array_equal(normalized_array, expected)) @require_torch def test_normalize_tensor(self): feature_extractor = ImageFeatureExtractionMixin() tensor = torch.rand(16, 32, 3) mean = [0.1, 0.5, 0.9] std = [0.2, 0.4, 0.6] # mean and std can be passed as lists or tensors. expected = (tensor - torch.tensor(mean)) / torch.tensor(std) normalized_tensor = feature_extractor.normalize(tensor, mean, std) self.assertTrue(torch.equal(normalized_tensor, expected)) normalized_tensor = feature_extractor.normalize(tensor, torch.tensor(mean), torch.tensor(std)) self.assertTrue(torch.equal(normalized_tensor, expected)) # Normalize will detect automatically if channel first or channel last is used. tensor = torch.rand(3, 16, 32) expected = (tensor - torch.tensor(mean)[:, None, None]) / torch.tensor(std)[:, None, None] normalized_tensor = feature_extractor.normalize(tensor, mean, std) self.assertTrue(torch.equal(normalized_tensor, expected)) normalized_tensor = feature_extractor.normalize(tensor, torch.tensor(mean), torch.tensor(std)) self.assertTrue(torch.equal(normalized_tensor, expected)) def test_center_crop_image(self): feature_extractor = ImageFeatureExtractionMixin() image = get_random_image(16, 32) # Test various crop sizes: bigger on all dimensions, on one of the dimensions only and on both dimensions. crop_sizes = [8, (8, 64), 20, (32, 64)] for size in crop_sizes: cropped_image = feature_extractor.center_crop(image, size) self.assertTrue(isinstance(cropped_image, PIL.Image.Image)) # PIL Image.size is transposed compared to NumPy or PyTorch (width first instead of height first). expected_size = (size, size) if isinstance(size, int) else (size[1], size[0]) self.assertEqual(cropped_image.size, expected_size) def test_center_crop_array(self): feature_extractor = ImageFeatureExtractionMixin() image = get_random_image(16, 32) array = feature_extractor.to_numpy_array(image) # Test various crop sizes: bigger on all dimensions, on one of the dimensions only and on both dimensions. crop_sizes = [8, (8, 64), 20, (32, 64)] for size in crop_sizes: cropped_array = feature_extractor.center_crop(array, size) self.assertTrue(isinstance(cropped_array, np.ndarray)) expected_size = (size, size) if isinstance(size, int) else size self.assertEqual(cropped_array.shape[-2:], expected_size) # Check result is consistent with PIL.Image.crop cropped_image = feature_extractor.center_crop(image, size) self.assertTrue(np.array_equal(cropped_array, feature_extractor.to_numpy_array(cropped_image))) @require_torch def test_center_crop_tensor(self): feature_extractor = ImageFeatureExtractionMixin() image = get_random_image(16, 32) array = feature_extractor.to_numpy_array(image) tensor = torch.tensor(array) # Test various crop sizes: bigger on all dimensions, on one of the dimensions only and on both dimensions. crop_sizes = [8, (8, 64), 20, (32, 64)] for size in crop_sizes: cropped_tensor = feature_extractor.center_crop(tensor, size) self.assertTrue(isinstance(cropped_tensor, torch.Tensor)) expected_size = (size, size) if isinstance(size, int) else size self.assertEqual(cropped_tensor.shape[-2:], expected_size) # Check result is consistent with PIL.Image.crop cropped_image = feature_extractor.center_crop(image, size) self.assertTrue(torch.equal(cropped_tensor, torch.tensor(feature_extractor.to_numpy_array(cropped_image)))) @require_vision class LoadImageTester(unittest.TestCase): def test_load_img_url(self): img = load_image(INVOICE_URL) img_arr = np.array(img) self.assertEqual(img_arr.shape, (1061, 750, 3)) @is_flaky() def test_load_img_url_timeout(self): with self.assertRaises((ReadTimeout, ConnectTimeout)): load_image(INVOICE_URL, timeout=0.001) def test_load_img_local(self): img = load_image("./tests/fixtures/tests_samples/COCO/000000039769.png") img_arr = np.array(img) self.assertEqual( img_arr.shape, (480, 640, 3), ) def test_load_img_base64_prefix(self): try: tmp_file = tempfile.mktemp() with open(tmp_file, "wb") as f: http_get( "https://huggingface.co/datasets/hf-internal-testing/dummy-base64-images/raw/main/image_0.txt", f ) with open(tmp_file, encoding="utf-8") as b64: img = load_image(b64.read()) img_arr = np.array(img) finally: os.remove(tmp_file) self.assertEqual(img_arr.shape, (64, 32, 3)) def test_load_img_base64(self): try: tmp_file = tempfile.mktemp() with open(tmp_file, "wb") as f: http_get( "https://huggingface.co/datasets/hf-internal-testing/dummy-base64-images/raw/main/image_1.txt", f ) with open(tmp_file, encoding="utf-8") as b64: img = load_image(b64.read()) img_arr = np.array(img) finally: os.remove(tmp_file) self.assertEqual(img_arr.shape, (64, 32, 3)) def test_load_img_rgba(self): dataset = datasets.load_dataset("hf-internal-testing/fixtures_image_utils", "image", split="test") img = load_image(dataset[0]["file"]) # img with mode RGBA img_arr = np.array(img) self.assertEqual( img_arr.shape, (512, 512, 3), ) def test_load_img_la(self): dataset = datasets.load_dataset("hf-internal-testing/fixtures_image_utils", "image", split="test") img = load_image(dataset[1]["file"]) # img with mode LA img_arr = np.array(img) self.assertEqual( img_arr.shape, (512, 768, 3), ) def test_load_img_l(self): dataset = datasets.load_dataset("hf-internal-testing/fixtures_image_utils", "image", split="test") img = load_image(dataset[2]["file"]) # img with mode L img_arr = np.array(img) self.assertEqual( img_arr.shape, (381, 225, 3), ) def test_load_img_exif_transpose(self): dataset = datasets.load_dataset("hf-internal-testing/fixtures_image_utils", "image", split="test") img_file = dataset[3]["file"] img_without_exif_transpose = PIL.Image.open(img_file) img_arr_without_exif_transpose = np.array(img_without_exif_transpose) self.assertEqual( img_arr_without_exif_transpose.shape, (333, 500, 3), ) img_with_exif_transpose = load_image(img_file) img_arr_with_exif_transpose = np.array(img_with_exif_transpose) self.assertEqual( img_arr_with_exif_transpose.shape, (500, 333, 3), ) class UtilFunctionTester(unittest.TestCase): def test_get_image_size(self): # Test we can infer the size and channel dimension of an image. image = np.random.randint(0, 256, (32, 64, 3)) self.assertEqual(get_image_size(image), (32, 64)) image = np.random.randint(0, 256, (3, 32, 64)) self.assertEqual(get_image_size(image), (32, 64)) # Test the channel dimension can be overriden image = np.random.randint(0, 256, (3, 32, 64)) self.assertEqual(get_image_size(image, channel_dim=ChannelDimension.LAST), (3, 32)) def test_infer_channel_dimension(self): # Test we fail with invalid input with pytest.raises(ValueError): infer_channel_dimension_format(np.random.randint(0, 256, (10, 10))) with pytest.raises(ValueError): infer_channel_dimension_format(np.random.randint(0, 256, (10, 10, 10, 10, 10))) # Test we fail if neither first not last dimension is of size 3 or 1 with pytest.raises(ValueError): infer_channel_dimension_format(np.random.randint(0, 256, (10, 1, 50))) # But if we explicitly set one of the number of channels to 50 it works inferred_dim = infer_channel_dimension_format(np.random.randint(0, 256, (10, 1, 50)), num_channels=50) self.assertEqual(inferred_dim, ChannelDimension.LAST) # Test we correctly identify the channel dimension image = np.random.randint(0, 256, (3, 4, 5)) inferred_dim = infer_channel_dimension_format(image) self.assertEqual(inferred_dim, ChannelDimension.FIRST) image = np.random.randint(0, 256, (1, 4, 5)) inferred_dim = infer_channel_dimension_format(image) self.assertEqual(inferred_dim, ChannelDimension.FIRST) image = np.random.randint(0, 256, (4, 5, 3)) inferred_dim = infer_channel_dimension_format(image) self.assertEqual(inferred_dim, ChannelDimension.LAST) image = np.random.randint(0, 256, (4, 5, 1)) inferred_dim = infer_channel_dimension_format(image) self.assertEqual(inferred_dim, ChannelDimension.LAST) # We can take a batched array of images and find the dimension image = np.random.randint(0, 256, (1, 3, 4, 5)) inferred_dim = infer_channel_dimension_format(image) self.assertEqual(inferred_dim, ChannelDimension.FIRST) def test_get_channel_dimension_axis(self): # Test we correctly identify the channel dimension image = np.random.randint(0, 256, (3, 4, 5)) inferred_axis = get_channel_dimension_axis(image) self.assertEqual(inferred_axis, 0) image = np.random.randint(0, 256, (1, 4, 5)) inferred_axis = get_channel_dimension_axis(image) self.assertEqual(inferred_axis, 0) image = np.random.randint(0, 256, (4, 5, 3)) inferred_axis = get_channel_dimension_axis(image) self.assertEqual(inferred_axis, 2) image = np.random.randint(0, 256, (4, 5, 1)) inferred_axis = get_channel_dimension_axis(image) self.assertEqual(inferred_axis, 2) # We can take a batched array of images and find the dimension image = np.random.randint(0, 256, (1, 3, 4, 5)) inferred_axis = get_channel_dimension_axis(image) self.assertEqual(inferred_axis, 1)