-sN,--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.
-oFORMAT,--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.
-ePROFILE,--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.
-iPROFILE,--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.