Mogrify uses almost the same options and the same syntax that the Convert utility but the main difference between these two utilities is:
Convert can save the image processing tasks in a new file but Mogrify overwrites them on the file that it is working on. Here is the syntax:
mogrify [ options ...] file
Another difference between these two utilities is that we can make some graphic with
convert, define a canvas for it and save the result in a file whose name and format we specify but
mogrify only works on existing files. It is unable to create a new file. For example if do not already have a file named
line.bmp then the following command will produce an error:
mogrify size 80x100 xc:white draw 'line 10,10 70,90' ...