Whole-slide imaging — pyramid inspection & static overview preview (web)

Inspect a whole-slide pyramid and preview its static overview in the browser.

Problem

You’ve loaded a DICOM Whole Slide Image (WSI) — a gigapixel pathology slide stored in a multi-resolution pyramid. Unlike radiology images which are single-resolution matrices, WSI files contain multiple pyramid levels at decreasing resolutions. You need to view and verify the static overview preview, which composites the lowest-resolution tiles into a single canvas as a “thumbnail” of the entire slide.

Steps

1. Open the WSI DICOM file (⌘O) — e.g. wsi-test.dcm (SM modality).

2. Verify the overview preview — the SM modality routes to a static overview preview, compositing tiles from the lowest-resolution pyramid level onto a canvas ([data-testid="wsi-overview-canvas"]).

3. Verify the canvas properties:

   • The canvas renders at the native resolution of the lowest pyramid level (e.g. 512×384)
   • All tiles are stitched together — 100% of pixels are non-black
   • Each of the 12 distinct tiles has a unique color (proving each tile position was rendered independently)

4. Negative check — load a non-WSI file (e.g. test.dcm). The WSI overview canvas should NOT render — the component only activates for SM modality.

Expected Result

• WSI overview canvas is visible for SM modality files.
• Canvas dimensions match the lowest pyramid level resolution.
• All tiles are composited (full stitch, no gaps).
• Non-WSI files do not trigger the overview canvas (count is 0).