WSI Viewer

A single digitised pathology slide can be a gigabyte or more: one image tens of thousands of pixels wide. Before this project, TPN's pathologists had to download each file from a shared drive and open it at a desktop workstation with licensed viewing software. Away from that desk, they couldn't report.

The problem

• Huge files. At 1GB+ per slide, downloading every case was slow and impractical.
• Tied to one machine. Reporting required a specific workstation with paid software installed.
• Off-the-shelf tools didn't fit. Existing products couldn't slot into TPN's workflow.

What I built

A whole-slide image viewer that runs in any modern browser, on a phone or a large monitor:

• Smooth deep zoom. Pan and zoom from the whole slide down to cellular detail without waiting for the full image.
• Mobile-ready controls. Pinch-to-zoom, a navigator minimap and touch-friendly controls for reviewing on the go.
• Open from a link. Slides open straight from a case, with no file transfer.

Under the hood

The key is never to send the whole image. Each slide is pre-processed into a multi-resolution pyramid of small tiles, and the viewer requests only the tiles visible at the current zoom level. Memory use stays flat, and a 1GB slide feels as responsive as a map app, even on modest hospital bandwidth.

The result

Pathologists and clinicians can now review slides anywhere, on whatever device is at hand. The viewer has served 150+ users and 1,000+ slide views, and it ended TPN's dependence on licensed desktop software.