Update canvas usage page with the following content.
Many times you have a script (be it Fred's, or Snibgo's) that takes a base image as an argument.
For example a script that takes a input and output image and processes it in some magical way :-)
CODE: SELECT ALL
do_some_magick input.png output.png
Many times I ask it to display the result on screen without saving to a file
do_some_magick input.png show:
But it has always been harder to just give a 'blank' input image to the script, requiring you to do things like...
convert -size 400x300 xc:Salmon miff:- | do_some_magick miff:- show:
Or modify the script to generate a blank starting image.
Well here is a tip for you... Supply a blank canvas image of any size or color as a single argument....
do_some_magick 'xc:Salmon[400x300!]' show:
NOTE the '!' is important as you are basically resizing a base xc: image, and without it the input will be a square 300x300 pixels (or something else if -size is set where it gets inserted into the IM command in the script).
from http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=28153
Update canvas usage page with the following content.