decode JPEG image data to numpy array (#29)

* decode JPEG image data to numpy array

* moved image_decode.py into module folder. Added test file template. TODO: Finish writing tests when image encode is finished

* added dummy variable

* linter changes

lte/modules/image_decode.py

@@ -0,0 +1,24 @@
+"""
+Decodes images from JPEG bytes to numpy array.
+"""
+
+import io
+
+from PIL import Image
+import numpy as np
+
+
+def decode(data: "io.BytesIO | bytes") -> np.ndarray:
+    """
+    Decodes a JPEG encoded image and returns it as a numpy array.
+
+    Args:
+        data: bytes object containing the JPEG encoded image
+        TODO: When encoding JPEG, make sure the input image only has 3 channels,
+              if original picture was a PNG (filter out A channel)
+    Returns:
+        NDArray with in RGB format. Shape is (Height, Width, 3)
+    """
+    image = Image.open(data, formats=["JPEG"])
+
+    return np.asarray(image)

lte/test_image_encode_decode.py

@@ -0,0 +1,27 @@
+"""
+Test image encode and decode.
+TODO: finish image encode and then write this test
+"""
+
+from lte.modules import image_decode
+
+
+def main() -> int:
+    # TODO: Get test images and Encode
+    raw_data = 0
+
+    # Decode
+    img_array = image_decode.decode(raw_data)
+
+    # Do checks
+    # eg. check output shape
+    return 0
+
+
+if __name__ == "__main__":
+    result_main = main()
+
+    if result_main < 0:
+        print(f"ERROR: Status code: {result_main}")
+
+    print("Done!")

requirements.txt

@@ -8,6 +8,9 @@ pytest
 opencv-python
 numpy
 
+# Module lte
+Pillow
+
 # Module mavlink
 dronekit