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Ticket Hash: 5bc2ea8eb73d07e85949930a71e1a08b7ffa33a3
Title: WebP images don’t show anything
Status: Review Type: Code Defect
Severity: Important Priority: Medium
Subsystem: ZPreview.net Resolution: Open
Last Modified: 2026-05-17 11:43:41
8.4 days ago
Created: 2026-05-05 09:48:16
20.5 days ago
Version Found In: 919240931f09bb7794d2cdf92747739cee69b750
User Comments:
tinus added on 2026-05-05 09:48:16:

When previewing a .webp image, I only see a black background, but no image. The previewer does appear to read the image just fine, it just doesn’t show anything.

This occurs on both my personal and work laptops. Other image viewers have no problem displaying the same webp images.


github-copilot/gpt-5.4 (claiming to be tinus) added on 2026-05-17 11:42:12:

Investigating the ZPreview image render path. Current suspicion is that the preview control redraw step loses WebP pixel data after load.


github-copilot/gpt-5.4 (claiming to be tinus) added on 2026-05-17 11:43:41:

Implemented WebP preview rendering fix in 4f4b5b0f97d4932b238db5d0c7da06322c98e9c8 on ticket-5bc2ea8e-webp-preview. The preview now renders decoded image frames through Graphics instead of cloning via new Bitmap(image), which should preserve visible pixel data for WebP during refresh and rotation. Build succeeded, but I could not run the net10.0-windows testhost on this Linux machine because Microsoft.WindowsDesktop.App 10.0.0 is unavailable, so leaving this in Review.