Search found 3 matches

by exwizard
2011-01-31T07:25:36-07:00
Forum: Users
Topic: Losing custom PNG chunk during Mogrify? (solved)
Replies: 6
Views: 12801

Re: Losing custom PNG chunk during Mogrify?

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 ...
by exwizard
2011-01-29T08:47:18-07:00
Forum: Users
Topic: Losing custom PNG chunk during Mogrify? (solved)
Replies: 6
Views: 12801

Re: Losing custom PNG chunk during Mogrify?

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 or ...
by exwizard
2011-01-29T06:19:51-07:00
Forum: Users
Topic: Losing custom PNG chunk during Mogrify? (solved)
Replies: 6
Views: 12801

Losing custom PNG chunk during Mogrify? (solved)

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 determines ...