NAME¶

vipsthumbnail - make thumbnails of image files

SYNOPSIS¶

vipsthumbnail [flags] imagefile1 imagefile2 ...

DESCRIPTION¶

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.

OPTIONS¶

-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.

-o FORMAT, --output=FORMAT

Set the output format string. The input filename has any file type suffix removed, then that value is substitued into FORMAT replacing %s. 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.

-p I, --interpolator=I

Resample with interpolator I. Use vips --list classes to see a list of valid interpolators. The default is bilinear.

-r, --sharpen=none|mild|MASKFILE

Images can look a little soft after shrinking. This option lets you specify a sharpening mask. Use "none" to disable sharpening, or "mild" to sharpen lightly, or give the filename of a custom mask file to use. The default is "mild". The built-in mild sharpen mask is:

3 3 24 0
-1 -1 -1
-1 32 -1
-1 -1 -1

-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 embdedded 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 axies, then any excess is cropped off.

-d, --delete

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

-v, --verbose

vipsthumbnail(1) normally runs silently, except for warning and error messages. This option makes it print a list of the operations it performs on each image.

RETURN VALUE¶

returns 0 on success and non-zero on error.

SEE ALSO¶

vipsheader(1)