## Problem As reported in https://gitlab.com/gitlab-org/gitlab/-/work_items/22133#note_3176104898, the "Toggle transparency checkerboard" button can appear on PNG/WebP images that have only a negligible number of transparent pixels (e.g., a few in a corner). Clicking the button in these cases produces no visible change, which confuses users into thinking it's a bug. The root cause is that the current implementation shows the button whenever **any** transparent pixel is detected, without considering whether the transparency is visually meaningful. ## Proposal Add a simple **5% transparency threshold**: only show the checkerboard toggle button when at least 5% of the image's pixels are transparent. This filters out images with incidental transparency artifacts while still catching images with meaningful transparent backgrounds. This is a pragmatic, minimal change (estimated ~3-4 lines of code) that addresses the immediate confusion. We will collect further feedback after shipping to determine whether the threshold needs adjustment or a more sophisticated approach (e.g., border-weighted detection) is warranted. ## References - Parent issue: https://gitlab.com/gitlab-org/gitlab/-/work_items/22133 - Feedback from @alyssatrinh: https://gitlab.com/gitlab-org/gitlab/-/work_items/22133#note_3176104898 - Investigation by @vanessaotto: https://gitlab.com/gitlab-org/gitlab/-/work_items/22133#note_3190577499