fix: Pillow examples using frombuffer (#535)

* Fix Pillow examples using frombuffer

The Pillow docs recommend always using the decoder arguments when
using frombuffer; see
https://pillow.readthedocs.io/en/stable/reference/Image.html

* Add PR number to release notes

* Remove a release notes change that was put in this PR by mistake

Author: jholveck

demos/cat-detector.py

@@ -281,7 +281,7 @@ def main() -> None:
             # We transfer the image from MSS to PyTorch via a Pillow Image.  Faster approaches exist (see
             # screenshot_to_tensor), but PIL is more readable.  The bulk of the time in this program is spent doing
             # the AI work, so we just use the most convenient mechanism.
-            img = Image.frombuffer("RGB", sct_img.size, sct_img.bgra, "raw", "BGRX")
+            img = Image.frombuffer("RGB", sct_img.size, sct_img.bgra, "raw", "BGRX", 0, 1)
 
             # We explicitly convert it to a tensor here, even though Torchvision can also convert it in the preprocess
             # step.  This is so that we send it to the GPU before we do the preprocessing: PIL Images are always on

demos/tinytv-stream-simple.py

@@ -97,7 +97,7 @@ def main() -> None:
                     # The next step is to resize the image to fit the TinyTV's screen.  There's a great image
                     # manipulation library called PIL, or Pillow, that can do that.  Let's transfer the raw pixels in
                     # the ScreenShot object into a PIL Image.
-                    original_image = Image.frombuffer("RGB", screenshot.size, screenshot.bgra, "raw", "BGRX")
+                    original_image = Image.frombuffer("RGB", screenshot.size, screenshot.bgra, "raw", "BGRX", 0, 1)
 
                     # Now, we can resize it.  The resize method may stretch the image to make it match the TinyTV's
                     # screen; the advanced demo gives other options.  Using a reducing gap is optional, but speeds up

demos/tinytv-stream.py

@@ -348,7 +348,7 @@ def capture_image(
 
         while True:
             sct_img = sct.grab(rect)
-            pil_img = Image.frombuffer("RGB", sct_img.size, sct_img.bgra, "raw", "BGRX")
+            pil_img = Image.frombuffer("RGB", sct_img.size, sct_img.bgra, "raw", "BGRX", 0, 1)
             yield pil_img
 
 

demos/video-capture-simple.py

@@ -129,7 +129,7 @@ def main() -> None:
                 # use PIL: you can create an Image from the screenshot, and create a VideoFrame from that.  That said,
                 # if you want to boost the fps rate by about 50%, check out the full demo, and search for
                 # from_numpy_buffer.
-                img = Image.frombuffer("RGB", screenshot.size, screenshot.bgra, "raw", "BGRX")
+                img = Image.frombuffer("RGB", screenshot.size, screenshot.bgra, "raw", "BGRX", 0, 1)
                 frame = av.VideoFrame.from_image(img)
 
                 # When we encode frames, we get back a list of packets.  Often, we'll get no packets at first: the

docs/source/examples/pil.py

@@ -15,9 +15,9 @@
         sct_img = sct.grab(monitor)
 
         # Create the Image
-        img = Image.frombuffer("RGB", sct_img.size, sct_img.bgra, "raw", "BGRX")
+        img = Image.frombuffer("RGB", sct_img.size, sct_img.bgra, "raw", "BGRX", 0, 1)
         # The same, but less efficient:
-        # img = Image.frombuffer('RGB', sct_img.size, sct_img.rgb, 'raw', 'RGB')
+        # img = Image.frombuffer('RGB', sct_img.size, sct_img.rgb, 'raw', 'RGB', 0, 1)
 
         # And save it!
         output = f"monitor-{num}.png"

docs/source/release-history/v11.0.0.md

@@ -36,3 +36,10 @@ Device contexts are now acquired and released within each `grab()` call, allowin
 ### General Improvements
 
 The MSS context object will now always surface inner exceptions, even if `__exit__` may also generate an exception during tear-down.
+
+### Documentation
+
+The documentation has received numerous small improvements.  A few highlights:
+
+* The Pillow examples and demos using {py:meth}`PIL.Image.frombuffer` now explicitly specify the decoder arguments,
+  as recommended by Pillow.  (#535)

src/tests/third_party/test_pil.py

@@ -37,7 +37,7 @@ def test_pil_bgra(mss_impl: Callable[..., MSS]) -> None:
     with mss_impl() as sct:
         sct_img = sct.grab(box)
 
-    img = Image.frombuffer("RGB", sct_img.size, sct_img.bgra, "raw", "BGRX")
+    img = Image.frombuffer("RGB", sct_img.size, sct_img.bgra, "raw", "BGRX", 0, 1)
     assert img.mode == "RGB"
     assert img.size == sct_img.size