FA-78977 / Image orientation metadata / Member archive

Thumbnail ignores the axis swap for mirrored rotations · case 02

Tag 5 and 7 thumbnails are sized as landscape when the photo displays as portrait.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

Input [stored_w, stored_h, tag, box_w, box_h]. Compute the displayed thumbnail size: tags 5..8 swap the displayed dimensions (other values, including invalid tags, do not). Scale = min(box_w/dw, box_h/dh, 1) exactly (never upscale); each side is rounded half up and is at least 1 pixel.

Why this case matters

Camera, phone and scanner images carry an orientation hint separately from the stored pixels; galleries, thumbnailers, editors and upload pipelines must interpret it consistently or photos appear sideways, mirrored or doubly rotated.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: tags that swap displayed axes 0	`[9, 27]`	`[50, 17]`	Failed

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