Don't perform any colour transformations with decode_pixel_data() v2 (#63)

Author: scaramallion

docs/changes/v2.0.0.rst

@@ -3,12 +3,15 @@
 2.0.0
 =====
 
-Changes
-.......
-
 * Drop support for Python 3.7
 * Add supports for Python 3.11 and 3.12
 * Switched packaging and build to ``pyproject.toml``
 * Added type hints
 * Added support for version 2 of the pixel data decoding interface
 * Removed ``utils.reconstruct()``
+
+
+2.0.1
+=====
+
+* Don't apply any colour transformations when using ``decode_pixel_data()``

lib/interface/decode.cpp

@@ -40,11 +40,13 @@ std::string Decode(
     int outLength
         Expected length of the output array
     int colourTransform
-        JPGFLAG_MATRIX_COLORTRANSFORMATION_NONE 0
-        JPGFLAG_MATRIX_COLORTRANSFORMATION_YCBCR 1
-        JPGFLAG_MATRIX_COLORTRANSFORMATION_LSRCT 2
-        JPGFLAG_MATRIX_COLORTRANSFORMATION_RCT 2
-        JPGFLAG_MATRIX_COLORTRANSFORMATION_FREEFORM 3
+        The colour transform that's been applied prior to encoding, one of:
+
+        * JPGFLAG_MATRIX_COLORTRANSFORMATION_NONE 0
+        * JPGFLAG_MATRIX_COLORTRANSFORMATION_YCBCR 1
+        * JPGFLAG_MATRIX_COLORTRANSFORMATION_LSRCT 2
+        * JPGFLAG_MATRIX_COLORTRANSFORMATION_RCT 2
+        * JPGFLAG_MATRIX_COLORTRANSFORMATION_FREEFORM 3
 
     */
     // Check valid value

libjpeg/tests/test_handler.py

@@ -78,13 +78,6 @@ def test_invalid_colour_transform(self, add_invalid_colour):
         with pytest.raises(RuntimeError, match=msg):
             decode(data, -1)
 
-        with pytest.raises(RuntimeError, match=msg):
-            decode_pixel_data(
-                data,
-                photometric_interpretation="INVALID",
-                version=2,
-            )
-
 
 # ISO/IEC 10918 JPEG
 @pytest.mark.skipif(not HAS_PYDICOM, reason="No dependencies")

libjpeg/utils.py

@@ -210,10 +210,7 @@ def decode_pixel_data(
         return decode(src, transform, reshape=False)
 
     # Version 2
-    photometric_interpretation = kwargs.get("photometric_interpretation", None)
-    colour_transform = COLOURSPACE.get(photometric_interpretation, 0)
-
-    status, out, params = _libjpeg.decode(src, colour_transform, as_array=False)
+    status, out, params = _libjpeg.decode(src, colourspace=0, as_array=False)
     status = status.decode("utf-8")
     code, msg = status.split("::::")
     code = int(code)