I have fought with trying to remember the syntax for Imagemagik’s convert command for years. I finaly caved in [from my normal position of “if you can’t do it from the commandline, then you are a wimp” and sought out a gui to help me quickly convert images to use on a website. Or to just roll a picture 90 or 180 degrees. The easy solution and a standard ubuntu repository file is “converseen”. It can do batch conversions or on selected files. Gets the job done without the challenge of looking up all the arguments for “convert”.
"Do not meddle in the affairs of wizards, for they are subtle and quick to anger.” J.R.R Tolkien
Elizabeth City, NC