Use non nested images and batched text Idefics2/3 (#34222)

* add support for non nested images and add tests

* add tests error scenario

* fix style

* added single and no image to error tests

tests/models/idefics2/test_processor_idefics2.py

@@ -226,6 +226,73 @@ class Idefics2ProcessorTest(ProcessorTesterMixin, unittest.TestCase):
         self.assertEqual(inputs["input_ids"], expected_input_ids)
         # fmt: on
 
+    def test_non_nested_images_with_batched_text(self):
+        processor = self.get_processor()
+        processor.image_processor.do_image_splitting = False
+
+        image_str = "<image>"
+        text_str_1 = "In this image, we see"
+        text_str_2 = "bla, bla"
+
+        text = [
+            image_str + text_str_1,
+            text_str_2 + image_str + image_str,
+        ]
+        images = [self.image1, self.image2, self.image3]
+
+        inputs = processor(text=text, images=images, padding=True)
+
+        self.assertEqual(inputs["pixel_values"].shape, (2, 2, 3, 767, 980))
+        self.assertEqual(inputs["pixel_attention_mask"].shape, (2, 2, 767, 980))
+
+    def test_process_interleaved_images_prompts_image_error(self):
+        processor = self.get_processor()
+
+        text = [
+            "This is a test sentence.",
+            "In this other sentence we try some good things",
+        ]
+        images = [[self.image1], [self.image2]]
+        with self.assertRaises(ValueError):
+            processor(text=text, images=images, padding=True)
+        images = [[self.image1], []]
+        with self.assertRaises(ValueError):
+            processor(text=text, images=images, padding=True)
+
+        text = [
+            "This is a test sentence.<image>",
+            "In this other sentence we try some good things<image>",
+        ]
+        images = [[self.image1], [self.image2, self.image3]]
+        with self.assertRaises(ValueError):
+            processor(text=text, images=images, padding=True)
+        images = [[], [self.image2]]
+        with self.assertRaises(ValueError):
+            processor(text=text, images=images, padding=True)
+        images = [self.image1, self.image2, self.image3]
+        with self.assertRaises(ValueError):
+            processor(text=text, images=images, padding=True)
+        images = [self.image1]
+        with self.assertRaises(ValueError):
+            processor(text=text, images=images, padding=True)
+
+        text = [
+            "This is a test sentence.",
+            "In this other sentence we try some good things<image>",
+        ]
+        images = [[self.image1], []]
+        with self.assertRaises(ValueError):
+            processor(text=text, images=images, padding=True)
+        images = [[], [self.image2]]
+        with self.assertRaises(ValueError):
+            processor(text=text, images=images, padding=True)
+        images = [self.image1, self.image2]
+        with self.assertRaises(ValueError):
+            processor(text=text, images=images, padding=True)
+        images = [self.image1]
+        with self.assertRaises(ValueError):
+            processor(text=text, images=images, padding=True)
+
     def test_apply_chat_template(self):
         # Message contains content which a mix of lists with images and image urls and string
         messages = [
@@ -275,13 +342,3 @@ class Idefics2ProcessorTest(ProcessorTesterMixin, unittest.TestCase):
         return ["lower newer <image>", "<image> upper older longer string"] + ["<image> lower newer"] * (
             batch_size - 2
         )
-
-    # Override as PixtralProcessor needs nested images to work properly with batched inputs
-    @require_vision
-    def prepare_image_inputs(self, batch_size: Optional[int] = None):
-        """This function prepares a list of PIL images for testing"""
-        if batch_size is None:
-            return super().prepare_image_inputs()
-        if batch_size < 1:
-            raise ValueError("batch_size must be greater than 0")
-        return [[super().prepare_image_inputs()]] * batch_size