ImageBlob regression in 27.9.1 and 27.10.0: all documented pixel formats misdecode; RGBA read in wrong byte order

Photoshop UXP Plugin API
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image_blob_screenshot
image_blob_screenshot1226×1000 299 KB

Since 27.9.1, ImageBlob → createObjectURL → <img> misdecodes every documented format. Verified with the attached minimal repro plugin: correct on 26.11.2, broken on 27.9.1 and 27.10.0, same machine (screenshots attached).

  • Gray (1), GrayscaleAlpha (2), RGB (3): silently scrambled, no exception thrown. The decoder appears to read at a 4-byte stride, so it also reads past the end of the buffer and renders stale process memory (output changes on every redraw). The docs’ own example, a 3-component buffer of [255,0,0] triplets, does not render red.

  • RGBA (4): channels rotated

    the decoder consumes bytes as literal A,R,G,B. Writing the same pixels with alpha first renders the true image (repro row 6). Bytes B,G,R,A (a little-endian 0xAARRGGBB word) do not render correctly (row 7), so it’s a byte-order change, not an endian swap.

The repro is self-contained (no build step, load via UDT), renders one known pattern through each format on both panel and modal-dialog surfaces, and prints expected results per row. Timing lines up with the new UI backend rollout, ImageBlob hands raw buffers to exactly that layer.

uxp-imageblob-repro.zip (206.6 KB)

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Yes, this is a known issue and has already been reported.

3

Thanks Haller. I was the one who posted it in the Drover thread 24 days ago, but I never got a response. Is that where did you saw it before? Do you know the Jira ticket number or what build the fix is targeted for?

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No, I haven’t seen it, but I know they’re already working on fixing the problem, maybe it’s already ready for the next update.

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Thanks, I am curious how you know that it is a known issue that they are working on? It is posted anywhere online?