Editing (resizing, format converting, compressing) images in the command line with ImageMagick (mogrify, convert)

Resize all tif images in the current directory:

mogrify -resize 25% 25% *.tif

Resize all jpeg images in the current directory to a width of 614 pixels and keep the image ratio constant:

mogrify -resize 614 *.jpg

As above, but resize the hight to 614 pixels:

mogrify -resize x614 *.jpg

Convert all bmp imgaes in the current directory into tiff images:

mogrify -format tiff *.bmp

Compress all tiff images in the current directory with ZIP compression:

mogrify -compress ZIP *.tiff

I tried to convert also pict files (from Macintosh), but without success, although the pict file format appears to be supported by Imagemagick. In order to make sure that ImageMagick knows that the file to convert is a pict file I used this command:

convert pict:Photo0024.PICT tiff:Photo0002.tif

There is also a picttoppm utility in the netpbm package, but it was not anymore included in the version that Suse 9 uses; so I couldn't check that out...

Interestingly PixiePlus can display pict files, where does it take the routines from?

If you have very large images, the default limits of ImageMagick are resulting in an error
(e.g. mogrify-im6.q16: width or height exceeds limit) and you need to edit /etc/ImageMagick-6/policy.xml!