I’ve been having some trouble printing a painting that I drew with an uncalibrated monitor. Since fixing the gamma levels of both the painting and my screen the colours are reproduced very well. I had to play around with the brightness a bit more, but it really comes down to the light you’re viewing the print with. It looks great in sunlight.
I had a digital painting of mine printed last week. I hadn’t printed anything in years, and was really excited about seeing how it’d look when printed professionally. I was really disappointed. First I also had to teach the guy at the shop how to use his software: he was convinced he had to crop the image, instead of expanding it to fit the page with padding. But that aside, the print was still poor quality. The colours were way off – much too green – and the whole image was considerably darker than I had intended. Looks like I should have paid attention to Yves Poissant after all.
Having done some reading on monitor calibration under GNU/Linux now, I think I have it sorted out. I don’t have any calibration hardware, so I calibrated my monitor with GAMMApage (a relative of monica). It produced the following xgamma command that I have set to run when I log in:
xgamma -rgamma 1.03 -ggamma 0.86 -bgamma 0.67
My understanding of this is that my monitor now uses the standard gamma of 2.2. I also made a monitor profile with lprof, but since I just did it by sight I don’t think it makes much difference. Still, I’m using it for colour management in The GIMP just for completeness.
Now when I open my painting it looks much closer to how it printed: dark and green. But that’s no good! I need it to look like it did before, when my monitor’s gamma was set to 1.0. I know nothing about the maths behind gamma correction, but I guessed that the colour transform could be undone by simply inverting the gamma value. For example, my monitor’s red gamma is now 1.03, so I had to adjust the image’s red gamma by 1/1.03 = 0.97. Green and blue had to be adjusted by 1.16 and 1.49 respectively. These can all be adjusted using The GIMP’s Levels dialog: choose the Channel from the top (Red / Green / Blue) and enter the gamma value for that channel in the middle box of the Input Levels (it defaults to 1.00 in the dialog). You can update all chanels at once. You can also save the levels settings so you can apply the same transformation to all images you made with your uncalibrated monitor.
The results on-screen are promising. Here you can see the original image (which printed very poorly) on the left, and image adjusted for my newly-calibrated monitor on the right:
Gamma: uncalibrated (left) vs calibrated and compensated (right)
I’ll take it to be printed again shortly and report back. I’m having fun playing with the levels now, though, so I might adjust it a bit more first.
Nothing like a bit of superannuation management to inspire one get back into blogging!
It’s great to be home, apart from the accounting. Over the past few months I’ve gone back and visited most of the places and almost all of the people I missed while I was in Japan. It feels so good. There’s nothing like a smell to provoke memories! Just last week we were in Sydney, and I must say, North Ryde smells great. Who would have thought it?
Having dragged her all around the world, it was clearly my turn. Jodie and I are now living in Melbourne. We’re staying with her parents until we find our own house. We’re hoping to buy but can’t afford it until I find work.
I spent February working on my portfolio. I painted a forest and cleaned up some old projects including the site theme itself.
While it’s great to be home, I’m already missing Japan! I keep putting off contacting our friends. Now the Japanese school year is over I’m afraid I’ve missed my chance for some people. Kaz called me last night to remind me that I’m missing cherry blossom season, and all the partying that goes along with it. Thanks, Kaz! You should come here to enjoy experience autumn in Melbourne.
Please excuse the lateness of this post. I saved it as a draft before leaving Japan, and forgot to publish it! I left on the 20th of December 2007.
It’s amazing to think we’ve been here for (*almost) 16 months. It’s flown by, but at the same time my old life in Australia seems like a dream.
Jodie has done an excellent job selling our furniture. For a while it looked like we’d be stuck with collection fees for some things, but everything was sold just in time. Yesterday four Aussies came to look at the fridge and left with as much stuff as they could carry, including a huge bag full of bedding (the previous tenants left a lot of stuff here).
I’m really excited about going back. Right now the thing I miss most is Pebbly Beach. But I know that I’ll miss a lot of things from here, too. The places in general and all our friends, naturally. I think I’ll also miss being welcomed to every shop, and Hankyu trains!