vipsthumbnail

vipsthumbnail — Introduction to vipsthumbnail, with examples

libvips ships with a handy command-line image thumbnailer, vipsthumbnail. This page introduces it, with some examples.

The thumbnailing functionality is implemented by vips_thumbnail() and vips_thumbnail_buffer() (which thumbnails an image held as a string), see the docs for details. You can use these functions from any language with a libvips binding. For example, from PHP you could write:

$filename = "image.jpg";
$image = Vips\Image::thumbnail($filename, 200, ["height" => 200]);
$image->writeToFile("my-thumbnail.jpg");

libvips options

vipsthumbnail supports the usual range of vips command-line options. A few of them are useful:

--vips-cache-trace shows each operation as libvips starts it. It can be handy to see exactly what operations vipsthumbnail is running for you.

--vips-leak turns on the libvips memory leak checker. As well as reporting leaks (hopefully there are none) it also tracks and reports peak memory use.

--vips-progress runs a progress indicator during computation. It can be useful to see where libvips is looping and how often.

--vips-info shows a higher level view of the operations that vipsthumbnail is running.