Fix inconsistent byte ordering on big endian systems (#23)

Author: scaramallion

.github/dependabot.yml

@@ -0,0 +1,10 @@
+# https://docs.github.com/code-security/dependabot/working-with-dependabot/keeping-your-actions-up-to-date-with-dependabot#example-dependabotyml-file-for-github-actions
+
+version: 2
+updates:
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every month
+      interval: "monthly"

.github/workflows/pr-tests.yml

@@ -12,7 +12,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
         arch: ['x64']
 
     steps:
@@ -42,7 +42,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
 
     steps:
     - uses: actions/checkout@v4
@@ -70,7 +70,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
 
     steps:
     - uses: actions/checkout@v4

.github/workflows/release-wheels.yml

@@ -42,9 +42,6 @@ jobs:
       matrix:
         include:
           # Windows 64 bit
-          - os: windows-latest
-            python: 38
-            platform_id: win_amd64
           - os: windows-latest
             python: 39
             platform_id: win_amd64
@@ -57,12 +54,11 @@ jobs:
           - os: windows-latest
             python: 312
             platform_id: win_amd64
+          - os: windows-latest
+            python: 313
+            platform_id: win_amd64
 
           # Linux 64 bit manylinux2014
-          - os: ubuntu-latest
-            python: 38
-            platform_id: manylinux_x86_64
-            manylinux_image: manylinux2014
           - os: ubuntu-latest
             python: 39
             platform_id: manylinux_x86_64
@@ -79,11 +75,12 @@ jobs:
             python: 312
             platform_id: manylinux_x86_64
             manylinux_image: manylinux2014
+          - os: ubuntu-latest
+            python: 313
+            platform_id: manylinux_x86_64
+            manylinux_image: manylinux2014
 
           # Linux aarch64
-          - os: ubuntu-latest
-            python: 38
-            platform_id: manylinux_aarch64
           - os: ubuntu-latest
             python: 39
             platform_id: manylinux_aarch64
@@ -96,11 +93,11 @@ jobs:
           - os: ubuntu-latest
             python: 312
             platform_id: manylinux_aarch64
+          - os: ubuntu-latest
+            python: 313
+            platform_id: manylinux_aarch64
 
           # MacOS x86_64
-          - os: macos-latest
-            python: 38
-            platform_id: macosx_x86_64
           - os: macos-latest
             python: 39
             platform_id: macosx_x86_64
@@ -113,11 +110,11 @@ jobs:
           - os: macos-latest
             python: 312
             platform_id: macosx_x86_64
+          - os: macos-latest
+            python: 313
+            platform_id: macosx_x86_64
 
           # MacOS arm64
-          - os: macos-latest
-            python: 38
-            platform_id: macosx_arm64
           - os: macos-latest
             python: 39
             platform_id: macosx_arm64
@@ -130,6 +127,9 @@ jobs:
           - os: macos-latest
             python: 312
             platform_id: macosx_arm64
+          - os: macos-latest
+            python: 313
+            platform_id: macosx_arm64
 
     steps:
     - uses: actions/checkout@v4
@@ -145,12 +145,12 @@ jobs:
     - uses: actions/setup-python@v4
       name: Install Python
       with:
-        python-version: '3.9'
+        python-version: '3.10'
 
     - name: Install dependencies
       run: |
         python -m pip install -U pip
-        python -m pip install cibuildwheel>=2.16
+        python -m pip install cibuildwheel>=2.21
 
     - name: Build wheels
       env:
@@ -170,52 +170,53 @@ jobs:
         name: wheel-${{ matrix.python }}-${{ matrix.platform_id }}
         path: ./dist
 
-  test-package:
-    name: Test built package
-    needs: [ build-wheels, build-sdist ]
-    runs-on: ubuntu-latest
-    timeout-minutes: 30
-    strategy:
-      fail-fast: false
-      matrix:
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
-
-    steps:
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v5
-      with:
-        python-version: ${{ matrix.python-version }}
-
-    - name: Download the wheels
-      uses: actions/download-artifact@v4
-      with:
-        path: dist/
-        merge-multiple: true
-
-    - name: Install from package wheels and test
-      run: |
-        python -m venv testwhl
-        source testwhl/bin/activate
-        python -m pip install -U pip
-        python -m pip install pytest numpy
-        python -m pip install -U --pre --find-links dist/ pyjpegls
-        python -m pytest --pyargs jpeg_ls.tests
-        deactivate
-
-    - name: Install from package tarball and test
-      run: |
-        python -m venv testsrc
-        source testsrc/bin/activate
-        python -m pip install -U pip
-        python -m pip install pytest numpy
-        python -m pip install -U dist/pyjpegls*.tar.gz
-        python -m pytest --pyargs jpeg_ls.tests
-        deactivate
+  # test-package:
+  #   name: Test built package
+  #   needs: [ build-wheels, build-sdist ]
+  #   runs-on: ubuntu-latest
+  #   timeout-minutes: 30
+  #   strategy:
+  #     fail-fast: false
+  #     matrix:
+  #       python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
+  #
+  #   steps:
+  #   - name: Set up Python ${{ matrix.python-version }}
+  #     uses: actions/setup-python@v5
+  #     with:
+  #       python-version: ${{ matrix.python-version }}
+  #
+  #   - name: Download the wheels
+  #     uses: actions/download-artifact@v4
+  #     with:
+  #       path: dist/
+  #       merge-multiple: true
+  #
+  #   - name: Install from package wheels and test
+  #     run: |
+  #       python -m venv testwhl
+  #       source testwhl/bin/activate
+  #       python -m pip install -U pip
+  #       python -m pip install pytest numpy
+  #       python -m pip install -U --pre --find-links dist/ pyjpegls
+  #       python -m pytest --pyargs jpeg_ls.tests
+  #       deactivate
+  #
+  #   - name: Install from package tarball and test
+  #     run: |
+  #       python -m venv testsrc
+  #       source testsrc/bin/activate
+  #       python -m pip install -U pip
+  #       python -m pip install pytest numpy
+  #       python -m pip install -U dist/pyjpegls*.tar.gz
+  #       python -m pytest --pyargs jpeg_ls.tests
+  #       deactivate
 
   # See: https://github.com/pypa/gh-action-pypi-publish/discussions/15
   deploy:
     name: Upload wheels to PyPI
-    needs: [ test-package ]
+    # needs: [ test-package ]
+    needs: [ build-wheels, build-sdist ]
     runs-on: ubuntu-latest
     timeout-minutes: 10
     environment:

jpeg_ls/CharLS.py

@@ -31,7 +31,7 @@ def encode(
     interleave_mode: Union[int, None] = None
 ) -> np.ndarray:
     """Encode grey-scale image via JPEG-LS using CharLS implementation."""
-    if data_image.dtype == np.uint16 and np.max(data_image) <= 255:
+    if data_image.dtype.itemsize == 2 and np.max(data_image) <= 255:
         data_image = data_image.astype(np.uint8)
 
     buffer = encode_array(data_image, lossy_error, interleave_mode)
@@ -129,11 +129,8 @@ def encode_array(
     bytearray
         The encoded JPEG-LS codestream.
     """
-    if arr.dtype == np.uint8:
-        bytes_per_pixel = 1
-    elif arr.dtype == np.uint16:
-        bytes_per_pixel = 2
-    else:
+    bytes_per_pixel = arr.dtype.itemsize
+    if bytes_per_pixel not in (1, 2) or arr.dtype.kind != "u":
         raise ValueError(
             f"Invalid ndarray dtype '{arr.dtype}', expecting np.uint8 or np.uint16."
         )
@@ -309,7 +306,7 @@ def encode_pixel_data(src: bytes, lossy_error: int = 0, **kwargs: Any) -> bytear
     Parameters
     ----------
     src : bytes
-        The image data to be JPEG-LS encoded.
+        The little-endian ordered image data to be JPEG-LS encoded.
     lossy_error : int, optional
         The absolute value of the allowable error when encoding using
         near-lossless, default ``0`` (lossless). For example, if using 8-bit
@@ -384,7 +381,7 @@ def jlsread(src: JLSSourceType) -> np.ndarray:
     im, info = decode_buffer(buffer)
 
     bytes_per_pixel = math.ceil(info["bits_per_sample"] / 8)
-    arr = np.frombuffer(im, dtype=f"u{bytes_per_pixel}")
+    arr = np.frombuffer(im, dtype=f"<u{bytes_per_pixel}")
     rows = info["height"]
     columns = info["width"]
     samples_per_pixel = info["components"]
@@ -413,7 +410,8 @@ def decode_buffer(src: Union[bytes, bytearray]) -> Tuple[bytearray, Dict[str, in
     Returns
     -------
     tuple[bytearray, dict[str, int]]
-        The decoded (image data, image metadata).
+        The decoded (image data, image metadata). The image data will use little-endian
+        byte ordering for multi-byte pixels.
     """
     return _CharLS._decode(src), _CharLS.read_header(src)
 
@@ -437,6 +435,7 @@ def decode_pixel_data(src: Union[bytes, bytearray], **kwargs: Any) -> Tuple[byte
     Returns
     -------
     tuple[bytearray, dict[str, int]]
-        The decoded (image data, image metadata).
+        The decoded (image data, image metadata). The image data will use little-endian
+        byte ordering for multi-byte pixels.
     """
     return decode_buffer(src)