| These are primarily notes|
It won't be complete in any sense.
It exists to contain fragments of useful information.
The command line swiss army knife for image conversions
On geometry specifications
You can sometimes avoid having to know the image size. For example, to take 5 pixels off the top and left, 15 off the right, and 10 off the bottom edge, without specifying an image size:
convert -crop +5+5 -crop -15-10 bordered.png borderless.png
Convert: geometry does not contain image
Can be triggered by using -trim while the entire image is just one color.
Editing Unknown field with tag 40961 (0xa001) encountered. `TIFFReadCustomDirectory'.
This is a warning, telling you that this field has been ignored. This particular tag refers to the color space, meaning that the colors may not be interpreted as specified - which can have an effect anywhere between none at all and 'uuuuugly'.