Added a test to run classify_async in region of interest mode

mediapipe/tasks/python/test/vision/image_classifier_test.py

@@ -476,6 +476,32 @@ class ImageClassifierTest(parameterized.TestCase):
       classifier.classify_async(self.test_image, timestamp)
     classifier.close()
 
+  def test_classify_async_succeeds_with_region_of_interest(self):
+    observed_timestamp_ms = -1
+
+    def check_result(result: _ClassificationResult, unused_output_image: _Image,
+                     timestamp_ms: int):
+      self.assertEqual(result, _generate_soccer_ball_results(timestamp_ms))
+      self.assertLess(observed_timestamp_ms, timestamp_ms)
+      self.observed_timestamp_ms = timestamp_ms
+
+    classifier_options = _ClassifierOptions(max_results=1)
+    options = _ImageClassifierOptions(
+      base_options=_BaseOptions(model_asset_path=self.model_path),
+      running_mode=_RUNNING_MODE.LIVE_STREAM,
+      classifier_options=classifier_options,
+      result_callback=check_result)
+    classifier = _ImageClassifier.create_from_options(options)
+    # Load the test image.
+    test_image = _Image.create_from_file(
+      test_utils.get_test_data_path('multi_objects.jpg'))
+    # NormalizedRect around the soccer ball.
+    roi = _NormalizedRect(x_center=0.532, y_center=0.521, width=0.164,
+                          height=0.427)
+    for timestamp in range(0, 300, 30):
+      classifier.classify_async(test_image, timestamp, roi)
+    classifier.close()
+
 
 if __name__ == '__main__':
   absltest.main()