Add ImageFeatureExtractionMixin (#10905)

* Add ImageFeatureExtractionMixin

* Add dummy vision objects

* Add require_vision

* Add tests

* Fix test

src/transformers/testing_utils.py

@@ -39,6 +39,7 @@ from .file_utils import (
     is_torch_available,
     is_torch_tpu_available,
     is_torchaudio_available,
+    is_vision_available,
 )
 from .integrations import is_optuna_available, is_ray_available
 
@@ -229,12 +230,9 @@ def require_torch_scatter(test_case):
 
 def require_torchaudio(test_case):
     """
-    Decorator marking a test that requires torchaudio.
-
-    These tests are skipped when torchaudio isn't installed.
-
+    Decorator marking a test that requires torchaudio. These tests are skipped when torchaudio isn't installed.
     """
-    if not is_torchaudio_available:
+    if not is_torchaudio_available():
         return unittest.skip("test requires torchaudio")(test_case)
     else:
         return test_case
@@ -242,10 +240,7 @@ def require_torchaudio(test_case):
 
 def require_tf(test_case):
     """
-    Decorator marking a test that requires TensorFlow.
-
-    These tests are skipped when TensorFlow isn't installed.
-
+    Decorator marking a test that requires TensorFlow. These tests are skipped when TensorFlow isn't installed.
     """
     if not is_tf_available():
         return unittest.skip("test requires TensorFlow")(test_case)
@@ -255,10 +250,7 @@ def require_tf(test_case):
 
 def require_flax(test_case):
     """
-    Decorator marking a test that requires JAX & Flax
-
-    These tests are skipped when one / both are not installed
-
+    Decorator marking a test that requires JAX & Flax. These tests are skipped when one / both are not installed
     """
     if not is_flax_available():
         test_case = unittest.skip("test requires JAX & Flax")(test_case)
@@ -267,10 +259,7 @@ def require_flax(test_case):
 
 def require_sentencepiece(test_case):
     """
-    Decorator marking a test that requires SentencePiece.
-
-    These tests are skipped when SentencePiece isn't installed.
-
+    Decorator marking a test that requires SentencePiece. These tests are skipped when SentencePiece isn't installed.
     """
     if not is_sentencepiece_available():
         return unittest.skip("test requires SentencePiece")(test_case)
@@ -280,10 +269,7 @@ def require_sentencepiece(test_case):
 
 def require_tokenizers(test_case):
     """
-    Decorator marking a test that requires 🤗 Tokenizers.
-
-    These tests are skipped when 🤗 Tokenizers isn't installed.
-
+    Decorator marking a test that requires 🤗 Tokenizers. These tests are skipped when 🤗 Tokenizers isn't installed.
     """
     if not is_tokenizers_available():
         return unittest.skip("test requires tokenizers")(test_case)
@@ -312,11 +298,21 @@ def require_scatter(test_case):
         return test_case
 
 
+def require_vision(test_case):
+    """
+    Decorator marking a test that requires the vision dependencies. These tests are skipped when torchaudio isn't
+    installed.
+    """
+    if not is_vision_available():
+        return unittest.skip("test requires vision")(test_case)
+    else:
+        return test_case
+
+
 def require_torch_multi_gpu(test_case):
     """
-    Decorator marking a test that requires a multi-GPU setup (in PyTorch).
-
-    These tests are skipped on a machine without multiple GPUs.
+    Decorator marking a test that requires a multi-GPU setup (in PyTorch). These tests are skipped on a machine without
+    multiple GPUs.
 
     To run *only* the multi_gpu tests, assuming all test names contain multi_gpu: $ pytest -sv ./tests -k "multi_gpu"
     """