Datachunk list image compression. Closes #234 (#235)

* feat(images): Adding images support to DataChunk.

* feat(test): Added unittest for DataChunk.

* fix(gray images): Added support for gray images.

* fix()HW1 instead of HW.

chimerapy/engine/networking/data_chunk.py

@@ -27,11 +27,13 @@ def __init__(self):
         # Creating mapping from content_type and compression method
         self._content_type_2_serial_mapping = {
             "image": (self._serialize_image, self._deserialize_image),
+            "images": (self._serialize_images, self._deserialize_images),
         }
 
         # Creating mapping for checking content_type
         self._content_type_2_checks_mapping = {
             "image": self._check_image,
+            "images": self._check_images,
         }
 
         # Adding default key-value pair
@@ -86,12 +88,29 @@ def _check_image(self, image: np.ndarray):
             image.dtype == np.uint8
         ), f"Numpy image needs to be np.uint8, currently {image.dtype}"
 
+    def _check_images(self, images: List[np.ndarray]):
+        assert isinstance(images, list)
+
     def _serialize_image(self, image: np.ndarray):
+        if len(image.shape) == 2:
+            return simplejpeg.encode_jpeg(
+                np.ascontiguousarray(np.expand_dims(image, axis=-1)), colorspace="GRAY"
+            )
         return simplejpeg.encode_jpeg(np.ascontiguousarray(image))
 
     def _deserialize_image(self, image_bytes: bytes):
+        # Obtain header first
+        header = simplejpeg.decode_jpeg_header(image_bytes)
+        if header[2] == "Gray":
+            return np.squeeze(simplejpeg.decode_jpeg(image_bytes, colorspace="GRAY"))
         return simplejpeg.decode_jpeg(image_bytes)
 
+    def _serialize_images(self, images: List[np.ndarray]):
+        return [self._serialize_image(image) for image in images]
+
+    def _deserialize_images(self, images_bytes: List[bytes]):
+        return [self._deserialize_image(image_bytes) for image_bytes in images_bytes]
+
     ####################################################################
     # (De)Serialization
     ####################################################################

test/test_data_chunk.py

@@ -18,7 +18,34 @@ def video_data_chunk():
     return data_chunk
 
 
-@pytest.mark.parametrize("data_chunk", [(lazy_fixture("video_data_chunk"))])
+@pytest.fixture
+def images_data_chunk():
+    data_chunk = cpe.DataChunk()
+    data_chunk.add(
+        "images",
+        [(np.random.rand(10, 10, 3) * 255).astype(np.uint8) for _ in range(10)],
+    )
+    return data_chunk
+
+
+@pytest.fixture
+def grey_images_data_chunk():
+    data_chunk = cpe.DataChunk()
+    data_chunk.add(
+        "images",
+        [(np.random.rand(10, 10) * 255).astype(np.uint8) for _ in range(10)],
+    )
+    return data_chunk
+
+
+@pytest.mark.parametrize(
+    "data_chunk",
+    [
+        (lazy_fixture("video_data_chunk")),
+        (lazy_fixture("images_data_chunk")),
+        (lazy_fixture("grey_images_data_chunk")),
+    ],
+)
 def test_jsonify_data_chunk(data_chunk):
     json_data = json.dumps(data_chunk.to_json())
     new_data_chunk = cpe.DataChunk.from_json(json.loads(json_data))