Path: utzoo!attcan!uunet!lll-winken!ncis.llnl.gov!ncis!helios.ee.lbl.gov!pasteur!ucbvax!bloom-beacon!apple!well!pokey From: pokey@well.UUCP (Jef Poskanzer) Newsgroups: comp.graphics Subject: Re: Extending PBM to handle Greyscale and Color images Message-ID: <10403@well.UUCP> Date: 18 Jan 89 23:10:50 GMT References: <589@midgard.Midgard.MN.ORG> Reply-To: Jef Poskanzer Organization: Paratheo-Anametamystikhood Of Eris Esoteric, Ada Lovelace Cabal Lines: 39 In the referenced message, dal@syntel.UUCP (Dale Schumacher) wrote: } "This is great, and very portable, but it only handles 1-bit deep }images (also know as bitmaps)". Being of the hacker mentality, I set }out to rectify this situation, and in the process located several problems }with portability in the original routines. At this point I have an }entirely rewritten set of routines that handles an image file format }that I'm calling PXM (Portable Pixmap), which is a superset of PBMs. Actually, I mentioned a while back that I was considering doing this very thing. (Article <6377@well.UUCP> of 26 Jun 88, in this newsgroup, titled "Upgrade PBM to PGM or PPM: opinions wanted.") I got a few responses, mostly pointing out that the Utah and IM Raster Toolkits already did what I was proposing to do. This I already knew (but needed to be reminded of), and is the main reason that PBM restricts itself to black and white: the operations you typically perform on black and white images are somewhat different from those for grayscale or color images. There was a niche unfilled, and I filled it. So, my opinion then and now is that extending PBM to gray and color is not a particularly great idea. Even so, I must admit that I have done it too, because like Dale I am of the hacker mentality. I just couldn't resist. There was some color hacking I wanted to do, so rather than bringing up and learning Utah or IM I just rolled my own. It was only a few days work, and in the process I learned more about what I really wanted to do with the color images. I don't feel like releasing this new stuff (yet), but if Dale releases his I'm sure I'll steal code from it! And the portability enhancements mentioned are, of course, welcome. }PS. Jef, I tried to send you mail but it bounced, please try to reach me }, or I have no idea how to get to any of those addresses, sorry. --- Jef Jef Poskanzer jef@rtsg.ee.lbl.gov ...well!pokey Yow! Are we interfacing yet?