Mogrify transforms an image or a sequence of images. These transforms include image scaling, image rotation, color reduction, and others. Each transmogrified image overwrites the corresponding original image, unless an option such as -format causes the output filename to be different from the input filename. The graphics formats supported by mogrify are listed in ImageMagick(1).
 
EXAMPLES
To convert all the TIFF files in a particular directory to JPEG, use:
mogrify -format jpeg *.tiff
To convert a directory full of JPEG images to thumbnails, use:
mogrify -size 120x120 -resize 120x120 +profile "*" *.jpg  
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