ImageMagick Command-Line Option Order (and Categories of Command-Line Parameters)

Question

My supervisor has asked me to convert the parts of our Perl scripts that use PerlMagick to instead pipe and use the command line version of ImageMagick (for various unrelate

Answer 1

Are convert operations performed from left to right? ie the order I pass them

Yes. If I take the following two examples, which are identical except for the operations order, I can expect different results based on the left to right.

convert rose: -sample 300% -wave 5x10 rose_post_wave.png
convert rose: -wave 5x10 -sample 300% rose_pre_wave.png

You can see the effects of the wave operation impact the image after, or before the sampling of the image.

What happens if I pass the same option twice? Are they performed separately?

The will be executed twice. No special locking, or automatic operation counting exists.

convert rose: -blur 0.5x0.5 -scale 300% rose_blur1.png
convert rose: -blur 0.5x0.5 -blur 0.5x0.5 -scale 300% rose_blur2.png