libvips

There’s a new version of vipsdisp, a gtk4 image viewer.

Another image viewer??

It can display huge (eg. 100,000 x 100,000 pixel and more) images quickly and without using much memory. It supports many scientific and technical image formats, including TIFF (with some OME-TIFF support), WEBP, JP2, JXL, HEIC, AVIF, PNG, JPEG, SVS, MRXS, NDPI, OpenEXR, GIF, PDF, SVG, FITS, HDR (Radiance), Matlab, NIfTI, Analyze, CSV, PPM, PFM, etc. It supports many pixel types, from 1 bit mono to 128-bit double precision complex.

What’s new

Version 2.5 adds save-as (contributed by angstyloop), better SVG and PDF support, improved mousewheel handling, selectable image backgrounds, and faster and smoother image animation.

Save-as supports all the image write features of libvips, so (for example), you can save any image as a DeepZoom pyramid, or as tiled pyramidal JPEG-compressed TIFF, or as JXL.

Install

There’s a binary on flathub, so it should be easy to try out. And there’s also a homebrew formula, which works surprisingly well.

Technical background

It has some interesting features:

• It doesn’t need to keep the whole image in memory. When possible, it will only decompress the pixels that it needs for display, and it understands most pyramidal image formats. This means you can open and view huge images quickly.

• It has threaded, asynchronous image repaint, so image tiles are computed in the background by a pool of workers and the screen is updated as they are finished. The interface should stay live even under very heavy load.

• It keeps a sparse pyramid of tiles as textures on the GPU. For each frame, it computes the set of visible tiles, and then the GPU scales, positions and composites just those tiles to the screen. CPU load should be low (except for the background workers haha). Hold down i (for “in”) or + to do a smooth zoom on the cursor. If you press “d” it toggles a debug display mode which shows the tiles being computed.

• Select Display Control Bar from the top-right menu and a useful set of visualization options appear. It supports four main display modes: Toilet Roll (sorry), Multipage, Animated, and Pages as Bands.

• In Toilet Roll mode, a multi-page image is presented as a tall, thin strip of images. In Multipage, you see a single page at a time, with a page-select spinner (you can also use the crtl-< and ctrl-> keys to flip pages). In animated mode, pages flip automatically on a timeout. In pages-as-bands mode, many-page single-band images (eg. OME-TIFF) are presented as a single colour image.

• You can select falsecolour and log-scale filters, useful for many scientific images. Scale and offset sliders let you adjust image brightness to see into darker areas (useful for HDR and science images). Pick Scale to search the window for min and max and set the scale and offset sliders to fill the range.