VIPS from the command-line 1 VIPS Library Using VIPS How to use the VIPS library from the command-line Use the vips command to execute VIPS operations from the command-line. You can show all classes with: vips list classes This produces output something like: VipsOperation (operation), operations VipsSystem (system), run an external command VipsArithmetic (arithmetic), arithmetic operations VipsBinary (binary), binary operations VipsAdd (add), add two images .... and so on Each line shows the canonical name of the class (for example VipsAdd), the class nickname (add in this case), and a short description. Some subclasses of operation will show more, for example subclasses of VipsForeign will show some of the extra flags supported by the file load/save operations. You can get help on a specific operation by running it with no arguments, for example: vips gamma produces the output: gamma an image usage: gamma in out where: in - Input image, input VipsImage out - Output image, output VipsImage optional arguments: exponent - Gamma factor, input gdouble operation flags: sequential-unbuffered vips gamma applies a gamma factor to an image. By default, it uses 2.4, the sRGB gamma factor, but you can specify any gamma with the exponent option. You can use the C API docs for vips_gamma() if you need more information. Use it from the command-line like this: vips gamma k2.jpg x.jpg --exponent 0.42 This will read file k2.jpg, un-gamma it, and write the result to file x.jpg. Some operations take arrays of values as arguments, for example, vips affine needs an array of four numbers for the 2x2 transform matrix. You pass arrays as space-separated lists, for example: vips affine k2.jpg x.jpg "2 0 0 1" Or vips bandjoin needs an array of input images to join, run it like this: vips bandjoin "k2.jpg k4.jpg" x.tif vips will automatically convert between image file formats for you. Input images are detected by sniffing their first few bytes; output formats are set from the filename suffix. You can see a list of all the supported file formats with something like: vips list classes | grep -i foreign Then get a list of the options a format supports with, for example: vips jpegsave You can pass options to the implicit load and save operations enclosed in square brackets after the filename. For example: vips affine k2.jpg x.jpg[Q=90,strip] "2 0 0 1" Will write x.jpg at quality level 90 and will strip all metadata from the image. Finally, vips has a couple of useful extra options. Use --vips-progress to get vips to display a simple progress indicator. Use --vips-leak and vips will leak-test on exit, and also display an estimate of peak memory use. VIPS comes with a couple of other useful programs. vipsheader is a command which can print image header fields. vipsedit can change fields in vips format images. vipsthumbnail can make image thumbnails quickly.