Legacy ImageMagick Discussions Archive

I've written a program that extracts the grAb chunk and then uses the oFFs chunk of a processed file in conjunction with the previously extracted grAb chunk to write a new grAb chunk (in the form of grAb xxxx - oFFs xxxx).

Thanks glennrp, pointing me at oFFs let me develop this workaround. Too bad ...

I think grAb is being used for historical reasons; switching to oFFs would break a lot of existing resources (something the maintainers of the engine are very much against even if a better implementation exists).

One solution would be to add grAb to the chunks known by IM and handle it like vpAg ...

Hi folks,

I'm trying to batch trim a number of PNG files that have extra transparent space. These PNGs have a custom chunk (grAb) described here: http://zdoom.org/wiki/GrAb

This is the command I am entering; it successfully trims the image but loses the grAb chunk. I know the grAb chunk ...