Imagemagick

📃 These are primarily notes, intended to be a collection of useful fragments, that will probably never be complete in any sense.

✎ This article/section is a stub — some half-sorted notes, not necessarily checked, not necessarily correct. Feel free to ignore, or tell me about it.

convert/mogrify notes

The command line swiss army knife for image conversions

http://www.imagemagick.org/script/command-line-processing.php

On geometry specifications

See e.g.

• http://www.imagemagick.org/script/command-line-processing.php#geometry
• http://www.imagemagick.org/Magick++/Geometry.html

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

Errors

✎ This article/section is a stub — some half-sorted notes, not necessarily checked, not necessarily correct. Feel free to ignore, or tell me about it.

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'.