toasty make-thumbnail
¶
The make-thumbnail
command takes a single input image and reduces it to a
96×45 pixel WWT thumbnail.
Usage¶
toasty make-thumbnail
[standard image-loading options]
{INPUT-IMAGE-PATH}
{OUTPUT-IMAGE-PATH}
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.
Example¶
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
Details¶
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.