vipsthumbnail - Man Page

vipsthumbnail [flags] imagefile1 imagefile2 ...

vipsthumbnail(1) processes each imagefile in turn, shrinking each image to fit within a 128 by 128 pixel square. The shrunk image is written to a new file named tn_imagefile.jpg. This program is typically faster and uses less memory than other image thumbnail programs.

For example:

$ vipsthumbnail fred.png jim.tif

will read image files fred.png and jim.tif and write thumbnails to the files tn_fred.jpg and tn_jim.jpg.

$ vipsthumbnail --size=64 -o thumbnails/%s.png fred.jpg

will read image file fred.jpg and write a 64 x 64 pixel thumbnail to the file thumbnails/fred.png.

-s N, --size=N

Set the output thumbnail size to N x N pixels.

You can use "MxN" to specify a rectangular bounding box. The image is shrunk so that it just fits within this area, images which are smaller than this are expanded.

Use "xN" or "Mx" to just resize on one axis.

Append "<" to only resize if the input image is smaller than the target, append ">" to only resize if the input image is larger than the target.

-o FORMAT, --output=FORMAT

Set the output format string. The input filename has any file type suffix removed, then that value is substituted into FORMAT replacing %s. If FORMAT is a relative path, the name of the input directory is prepended. In other words, any path in FORMAT is relative to the directory of the current input file.

The default value is tn_%s.jpg meaning JPEG output, with tn_ prepended. You can add format options too, for example tn_%s.jpg[Q=20] will write JPEG images with Q set to 20.

-e PROFILE, --eprofile=PROFILE

Export thumbnails with this ICC profile. Images are only colour-transformed if there is both an output and an input profile available. The input profile can either be embedded in the input image or supplied with the --iprofile option.

-i PROFILE, --iprofile=PROFILE

Import images with this ICC profile, if no profile is embedded in the image.  Images are only colour-transformed if there is both an output and an input profile available. The output profile should be supplied with the --oprofile option.

-c,  --crop

Crop the output image down. The image is shrunk so as to completely fill the bounding box in both axes, then any excess is cropped off.

-d,  --delete

Delete the output profile from the image. This can save a small amount of space.

-t,  --rotate

Auto-rotate images using EXIF orientation tags.

-a,  --linear

Shrink images in linear light colour space. This can be much slower.

returns 0 on success and non-zero on error. Error can mean one or more conversions failed.

vipsheader(1)