Perceiver interpolate position embedding (#30979)

* add test that currently fails

* test passed

* all perceiver passed

* fixup, style, quality, repo-consistency, all passed

* Apply suggestions from code review: default to False + compute sqrt once only

Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>

* fix a minor bracket

* replace dim with self._num_channels

* add arguments to the rest preprocessors

---------

Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>

tests/models/perceiver/test_modeling_perceiver.py

@@ -1031,3 +1031,23 @@ class PerceiverModelIntegrationTest(unittest.TestCase):
         )
 
         self.assertTrue(torch.allclose(logits[0, :3, :3, :3], expected_slice, atol=1e-4))
+
+    @slow
+    def test_inference_interpolate_pos_encoding(self):
+        image_processor = PerceiverImageProcessor(size={"height": 384, "width": 384})
+        model = PerceiverForImageClassificationLearned.from_pretrained("deepmind/vision-perceiver-learned")
+        model.to(torch_device)
+
+        # prepare inputs
+        image = prepare_img()
+        inputs = image_processor(image, return_tensors="pt").pixel_values.to(torch_device)
+        input_mask = None
+
+        # forward pass
+        with torch.no_grad():
+            outputs = model(inputs=inputs, attention_mask=input_mask, interpolate_pos_encoding=True)
+        logits = outputs.logits
+
+        # verify logits
+        expected_shape = torch.Size((1, model.config.num_labels))
+        self.assertEqual(logits.shape, expected_shape)