toasty make-thumbnail

The make-thumbnail command takes a single input image and reduces it to a 96×45 pixel WWT thumbnail.


toasty make-thumbnail
   [standard image-loading options]

See the Standard image-loading options section for documentation on those options.

The INPUT-IMAGE-PATH argument gives the filename of the input image.

The OUTPUT-IMAGE-PATH argument gives the filename of the thumbnail to be created. It is always saved in JPEG format, regardless of the filename extension.


When tiling a very large input image, the thumbnailing step may actually use too much memory or yield bad results. You can use this command to create a better thumbnail.

$ toasty tile-allsky --placeholder-thumbnail --outdir tiled allsky_64k.exr 8
$ toasty make-thumbnail allsky_2k.jpg tiled/thumb.jpg


The built-in tiling commands will attempt to create a thumbnail for you, but the results can be mediocre and the step can actually consume a great deal of memory for large input images. In conjunction with the --placeholder-thumbnail option to the tiling commands, this command can make it a bit easier to create a better-quality thumbnail by deriving it from a different, more task-appropriate source image.

The thumbnailing process crops the image to the required aspect ratio and then downsamples it using PIL. This algorithm isn’t always the best. If your high-resolution source image is “sparse” (i.e., mostly black), it may be useful to generate the thumbnail from a version of it that has already been downscaled. Because the final thumbnail size is so small, you can work from very modest source images if needed.