Browser tools

Tools that run on your machine

Small, single-purpose computer vision tools. Each one is something you can actually use, running the library itself, compiled to WebAssembly.

Every tool on this page runs entirely in your browser. The file you pick is decoded by the browser, handed to fovea compiled to WebAssembly, and the result is drawn in the tab. There is no upload and no server: the module is instantiated with an empty import object, so it has no way to reach the network at all. Once the page has loaded, you can disconnect and keep working.

That is not a privacy nicety. It is the reason you can use these at work, on a customer's image, without asking anyone.

Available now

• FAST corners

  Drop an image and watch the segment test fire. Then click any keypoint and read what the detector actually decided: the sixteen ring samples, which arc qualified and how long it was, the response in intensity units, and how far sub-pixel refinement moved the corner off the grid.

  features::detect::fast · retain_top_n · refine_corners · sobel_x / sobel_y

Being written

In rough order. Each goes live when it does something a page of prose could not.

• PNG chunk dissectorPlanned

  Every chunk in order, with the colour-space signals present or absent, and a verdict: no sRGB, no gAMA, no iCCP means every decoder that opens the file is guessing, and they do not guess alike.

• Gamma playgroundPlanned

  The same image downscaled gamma-blind and gamma-correct, with the difference map, the maximum error in levels, and the two numbers side by side. Part 2 of the series, made executable.

• Resize weight table inspectorPlanned

  The complete per-output-pixel table of source indices and weights, the anchor convention drawn on a pixel grid, and how it compares to what OpenCV, PIL and PyTorch each do. The reason a model trained on one resize loses two points served on another.

• Pipeline diffPlanned

  Two images in, and a diagnosis out: differences confined to one least significant bit and spatially uniform means rounding, edge ringing at a half-pixel offset means a resampling convention changed, and swapped channels look like swapped channels.