Good 'ol Slashdot has an article today on printing. One of the comments links my last diary here, spinning it as a "negative review of Argyll." Sigh.

Actually, my latest results with Argyll are very encouraging. I've made a number of profiles since the last post, and each is quite a bit better than the previous version. I now feel I have a good understanding of why my amateurish attempts had the quality problems they did.

I really like doing this kind of work. Learning and doing is the true spirit of free software - learning without doing gets you academic sterility, and doing without learning is all too often the way things are done in proprietary software.

Color science is continuing to evolve quickly. I think people got seduced by the fact that you can measure color rigorously and precisely, and characterize the color transformations done by actual devices such as monitors and printers. Color management, then, should be a snap - just make the colors on the printer match the colors on the screen, and you're done.

In fact, the way colors are perceived on the screen and on paper are quite different. Even worse, not all printers (or papers) are created equal. A ratty old inkjet on plain paper can't produce anywhere nearly the same range of colors as an Epson 870 on photo glossy. You have to do something with the colors outside the printer's capabilities. This process is called "gamut mapping", and the scientific understanding of how to best accomplish has only recently started to come into focus. Two important works from the last five years include Jan Morovic's thesis, and Fairchild's paper on hue linearization.

The goal of all this, I think, is to package up "best practices" in color management so that mere mortals can make and use color profiles with good results, without having to understand all the details of color science or our particular implementation. It still won't be for everybody - spectrophotometers still run around $1500, but I'd like for there to be a good solution for people serious about graphic arts.

Printing - not fun

I don't like standards committees, and I get the distinct impression that they don't like me. Thus, I think that one of the keys to happiness for me is to never get involved with a standards committee again.

I've been working on a protocol for hooking in printer drivers, called IJS (it's based on HP's hpijs, but driver-independent). I think it's going pretty well - HP's latest driver uses the IJS protocol, I've drafted a halfway decent spec, and I expect versions of Ghostscript to ship with IJS built by default pretty soon.

But life can't be so simple. As it turns out, the Free Standards Group has a Printing Working Group (not to be confused with the Printer Working Group, which is responsible for IPP) that is working on a standard to do pretty much the same thing as IJS. Well, I guess what they say is true: the great thing about standards is that there are so many to choose from.

I sent a rather passionately worded mail to their mailing list, requesting that they adopt wire protocol compatibility with IJS, but I'm really unsure how best to proceed. If I was a masochist with lots of extra time on my hands, I'd take active part in the PWG<2> and try to bully them into making a good standard, but it's just not how I want to spend my time.

I guess I'll be updating here as this thing plays out.

OpenSourceJapsEye

Awww, how cute. Our first determined troll.

These posts don't personally bother me that much, but I can imagine others not liking them. I think there's a good chance that our troller will get bored and go away, but of course I might be wrong. Obviously, there are other community sites where trolling is a deeply integrated part of the culture.

Amusingly, the concept of the trust metric seems to be working - OSJE is not certified. The problem is that one of the most popular parts of this site (the recent diary summary) doesn't use the trust metric at all. The simple thing to do would be to tighten up the recent diary list to only include cert'ed members. In the past, uncert'ed diary posts have been a good thing, largely because people can talk about the free software work they've done and thus elicit certifications. But at this point, it might be worth sacrificing, and I would ask that people use other channels of communication than Advogato diaries to get initial certs. After all, the site is pretty well established now. It should be reasonably easy for any serious free software developer to find somebody with an account here who they know well enough to ask for a cert.

I'm disheartened to hear reports that Advogato's S/N ratio is declining. It may well be true. If so, I'm not sure why. I fear that one reason may be that there's simply not as much interesting stuff happening in the free software world these days. It's hard for me to evaluate.

In any case, I think Advogato's S/N is pretty good. It's not fabulous, though. I'd like it to be better, and am definitely interested in tweaking the site to make it so. Of course, this work has to compete for time with the other stuff I'm doing (like actually doing free software, not to mention finishing my thesis), and it's especially hard to find motivation when I'm so unsure what would actually be effective. But I'm sure I'll find some more time to play with this site over the next few months.

As always, constructive suggestions are welcome.

Family

My mom is coming tomorrow (Christmas Eve). We'll all pile in the car and pick her up from the airport. It ought to be fun.

Max is at such a beautful age right now. Watching him begin to master language is such a joy. My favorite word of today was "chicken soup", which suggests that he's just about to break through the 2-syllable barrier. He asked for "Goodnight Moon" tonight, and I read it to him, twice. So sweet.

He's also into physical and spatial stuff. Alan and I were playing Hoppers this afternoon, and Max of course wanted to play too. He didn't seem to grasp the rules of the game at all (not surprising), but he did very much enjoy putting the little frogs on their pegs, and the patterns that resulted.

Alan is having a bit more of a difficult time right now. He spends a fair amount of time these days in a bad mood, easily getting frustrated, and obnoxious to boot. Heather and I have noted that it seems to be linked to time spent playing video games, particularly shooters like Nanosaur (which ordinarily we wouldn't let him play, but gave in because he likes dinosaurs so much). So we're going to cut down on the amount of time for video games and see if that helps.

His new passion continues to be stories. I'm reading him "Jurassic Park" now, and he's for the most part enjoying it, although it's a little too talky for his taste. It's amazing to me that he understands the story, not just what's going on, but the structure and texture of it as well. Early on in the book, he foresaw that Tina would get attacked by a dinosaur before any such thing was mentioned. Pretty basic for any fan of sci-fi thrillers, but impressive to me from a five year old.