Program that will batch adjust light levels on (ZIP and RAR) compressed CBZ and CBR files of scanned JPEGs?

July 2, 2004 10:47 AM

I have a large amount of CBZ and CBR files that are ZIP and RAR files respectively with scanned JPEGs of comic books inside them. Thing is, the levels on the scans are sometimes too dark or too bright. Is there a windows program that would batch fix the levels (like photoshop's Automatic Levels command) on the compressed archives without having to unzip pr unrar them first?
posted by signal to Computers & Internet (4 answers total)

I would say I'm 90% positive the answer is no, they are going to have to be uncompressed before hand. However, it would be trivial to have some kind of script uncompress them before doing the brightness magic and then compress them back. Particularly since both zip and rar have command line based tools.

A good command line based tool for adjusting levels is Image Magick. I'm pretty sure it's available for windows but I've never used it on that platform.

Again, the funny thing is, what's the point of compressing jpegs? You are unlikely to get more than a few percentage points of compression out of them. (I say again because of a thread the other day about compressing mp3s)
posted by RustyBrooks at 1:11 PM on July 2, 2004

Response by poster: The point is packaging entire comic books, where each page is 1 jpg file, as a single file, and reading them in CDisplay as single objects. It's not about the size.
I'll check out image magick, thanks.
posted by signal at 1:25 PM on July 2, 2004

Response by poster: One question, can ImageMagick do an autolevel thing? It looks like you can adjust levels or contrast manually, but not have it automagically decide what to do.
posted by signal at 2:17 PM on July 2, 2004

convert -equalize $in.jpg $out.jpg

Gotcha on the archives, hadn't really thought about that much.

Oh, and I don't recally ever really using equalize, so I kind of don't know if it's crap or not.
posted by RustyBrooks at 5:33 PM on July 3, 2004