posted Jun 7, 2010 10:22 AM by Daniel Marcus
If you're a graphic designer, a web designer, or just someone who appreciates your photos looking as good as possible on your screen, color calibration of your display is very important. This is something I ran in to just recently. I love my monitor, but colors were just not looking right. For example, here's a color palette.
Unfortunately, by comparison, what I saw on my screen was something like this:
The colors looked too cool, too washed out, and I could hardly tell the neutral beige from the background. I decided to look online for some good color calibration images, and I eventually found one, and attempted to calibrate my monitor. Unfortunately, the image was difficult to use, and yielded poor results. I instead decided to roll up my sleeves and make a good, high resolution, monitor color calibration image for personal use. I don't have the money to pay for such a solution, so this would allow me to calibrate my monitor for free, and with good results, if I did it right. The result came out well, and I decided to share it. Here, I'll present my color calibration chart, and help walk you through how to correctly calibrate your monitor. By the end of this little tutorial, you should have your window to the world brighter and more balanced than before.
First of all, you need to know a little about the way that monitors handle color. "Brightness" and "Contrast" don't usually mean what you'd like them to mean, with manufacturers today competing to add more "features" and provide "enhanced" image quality. We're not concerned with "pop" here, we're concerned with making things look right. First, let's take a look at my color calibration image. For those interested, I created it on the Open Source image manipulation program The GIMP ( website). What you see here is a scaled down, target image. The full downloadable chart is twice the size, and there's a link just below the image.
Download the Color Calibration ChartBefore I continue with the instructions, let's take a quick look at the calibration chart, and I'll explain how it works. The half-size version is a target. Don't use it to try to calibrate your monitor! Rather, this is what the full size version should look like when everything is done correctly. When you download the full size, you'll instead see that each square looks like this:
The square has two regions. The outside is a solid color, and the inside is a set of pixels that are a full-on full-off pattern designed to simulate the same color level as the outside region. For example, for 50% red, the outside is a darkish red that has each pixel half-on with the red channel. The pixels in the middle alternate between full-on red, and black. Sit back, blur your eyes, a bit, and the two squares will fade together, or at least they should. When the squares on the full-size color chart appear to be solid, your monitor is calibrated. Remember, though. Each monitor is a bit different, so for example, my Acer monitor is weighted towards lighter colors. Even when calibrated, colors appear a little lighter than they should be, but at least they are balanced, and I can tell the differences between similar colors.
The second area of the chart is a color tone check. It's done in a similar way.
This yellow matcher is designed with alternating red and green pixels in the middle. When viewed further away, and slightly burred, they form a solid 50% yellow which matches the outer square. Keep min mind, these two sample squares were designed for black backgrounds, so they won't look right outside of the downloadable calibration chart.
Now, back to what I was saying about the monitors. This is the trickiest part of the process, because all monitors act a bit differently. Ideally, I could tell you "just set your monitors brightness and contrast to 50%" and we could go from there. As it stands, though, this is not always the case. For example, on my Acer, "Contrast" actually dims the back light under about 70%. Set both channels to 50%, and then slowly increase either brightness or contrast (just one, not the other) until your monitor displays your whites as bright as possible while your blacks still appear to be completely black. If you are changing both black and white when you adjust the slider, you're adjusting the wrong one. For my monitor, I found that the way to do this was to set brightness to 50% and adjust contrast to 70%.
The color chart provides a white square and a black background. ( download) Check your color by looking at this part straight on. If you look from a slightly up or down angle, you will shift the colors. For this reason, many graphic designers still use tube-based monitors which do not have a color shift and have better contrast.
Aside: Two similar technologies exist to help with this color shift. Original LCD screens were TN-LCD or "twisted nematic", which is pretty much the same as TFT or "thin film transistor" LCD screens. Hitachi later developed a derivative screen called IPS or "in-plane switching" LCD which can improve the viewing angle significantly. A similar tact was taken by Olympus who designed an ultra-wide-angle LCD screen for their digital cameras called "HyperCrystal". Of the two, IPS has made an appearance on a few select monitors and on Apple's iPad. Both are likely to be replaced in the near future with superior OLED technology, but for now, we'll have to deal with what we have. Once your brightness and contrast are adjusted, it's time to move on to the trickier part of the process. Gamma.
Gamma allows you to get the distribution of color correct. This step will remove color caste, and make sure that grey is actually neutral.
Pull up the Gamma adjustment tool that comes with your system. Windows users should find this under the display properties for their graphics card, or on the software included with the graphics card. Mac OSX users should find this in their system control panel. Linux users should be able to search for "Gamma" in their system settings and find a tool there.
As a KDE user on Linux, the tool is imaginatively called "Gamma".
It has some built in test images of its own, but they're not adequate for what we are doing here. There are Red, Green, and Blue channels.
Start at the top of the calibration chart. ( download)
Looking straight on, adjust the blue slider until with your eyes slightly out of focus, the inside square fades in to the outside square. Once all three squares (25%, 50%, and 75%) appear to be the same lightness, move on the the next color.
When your red, green, and blue channels are all adjusted, double-check on the composite channel, and the white/grey squares should meld into one another.
To double-check your color tone, use the bottom part of the chart. Your yellow, cyan, and magenta boxes should each blend in to one another, and the color-shift boxes should appear neutral gray in the center of the cross hairs. Don't be surprised at how this may work out. This was my final setup:
Aside: If you're a Linux user, each user has the option to set their own Gamma. You may want to check the "save settings system wide" box to apply a good default to everyone's profile.
Once you're done adjusting your monitor, you may be surprised at how far off the color was of what you were looking at.
Good luck, and enjoy your now color calibrated screen. |
posted Apr 29, 2010 3:33 PM by Daniel Marcus
Once upon a time it was a sunny day in central North Carolina. My room mate, Chris, and I were in the midst of "dead" week (the week right before exams), and as the year was drawing to a close, we had decided it was about time to find a place to live for the next year.
We'd already looked around a little, one place was falling neatly into line, but we had an appointment scheduled with somewhere just down the road, and decided it was still worth checking it out. We got slightly lost on the way there, but we arrived in time to get the keys and a map and check out the various units they had available.
We walked up to the little office building passing by a lovely green swimming pool. (Green? Ah, whatever.) We picked up a map and some floor plans, signed for some keys, said our thanks-and-goodbye and walked back to Chris's car. Almost back, we stopped for a moment, when Chris realized he's forgotten to ask where the nearest bus stop was. He jogged back, got some dots put on the map, and then we went back for the second time and got in the car. As Chris turned on the engine, he paused and gave me a confused look.
"What?" I said. A benefit of being room mates for almost two years is that one word translates just fine into a full sentence.
"Did they ever give us the keys?" One more trip back to the office and we finally had a keyring with the necessary keys attached. As we pulled out of the little parking lot, Chris said absentmindedly, "It's like a sign from God..."
I glanced out the window and smirked a bit. Pffsh. Sign from God. We visited the first unit which was quite nice, and very roomy. Cheap too, if we could find a third person. We walked across the parking lot to the second unit. On our way down the short stairs to get in, I heard a quiet explicative from behind me. I raised an eyebrow and glanced back. Chris hurried to catch up, unlocked the door, and took off his flip-flop to leave it outside. Small wonder - a dog dropping the size of my fist had attached itself to the bottom of his footwear. We looked over the layout, Chris took a phone call, on our way out we talked to a grad student who was living in an adjoining unit, and began to head back to the car. If there was time, we still had two more units to look at, based on the map. We began an offhand conversation of pluses and minuses.
"It's a bit further than I would have liked." I mentioned.
"Yeah, but it's significantly cheaper." Chris did some quick mental math (he's good at that). "I mean, this place is only $3--"
Conversation was cut short as we both steadied ourselves. We glanced back. We had simultaneously tripped on a block of concrete protruding a good inch and a half higher than it should have.
We silently finished walking to the car, got in and drove the next block to where the next open unit was supposed to be. We spent 10 minutes wandering around before we realized we had accidentally circled back into the wrong place. The only thing of interest there was a community laundry room.
Once we found the right place and turned in, we could immediately tell it was a bit different than the last section of cottages. I consulted the map to see where to go. As Chris turned left, I mentioned that we still had one more side-road to go. "We have keys for that building, though", he said.
I frowned at the map. "It's not marked on here."
He held up the key for me to take a look at. I blinked, shrugged, and circled the unit on the map. Sure enough, she'd forgotten to mark the building.
We got out of the car, walked down into the unit, and noted that the doors weren't numbered. Again Chris consulted the key, did a little mental math and extrapolation, and deduced which door the key belonged to.
He cautiously tried it in the lock. It fit, he turned, he opened the door.
Poor girl. We must have scared her half to death.
We left, she yelled at us. Once we realized that she did not have a gun or pepper spray, we shamefacedly apologized profusely, and explained that we had been given a key to her apartment. We had not meant to just walk in on her. She handled it rather well, really, accepting our apology and advising us to watch out for any basement-level apartments. She told us about roaches and $450 electric bills. She did not need to tell us about management accidentally giving her key to prospective residents.
We got in the car, still slightly unnerved, and began to drive back to our university.
"Well," I said. "I guess since we weren't listening to the signs, God decided to send us a doozy."
After a few moments of silence, we both began laughing. We mentally crossed that particular complex off our list of potentials. |
posted Apr 22, 2010 11:52 PM by Daniel Marcus
He was slightly creepy, yet incredibly awesome. The arches of his spindly legs suspended him approximately half an inch off the ground. He turned with the eerily precise mechanics of a swiss clock, a movement more usually reserved for the abominations of man, not the wonders of the arachnid world. He turned, with sets of two legs, the front of one side, the back of the other, about ten degrees. Carefully picking them up, and touching them down in an elegant dance. This process was repeated with care until he faced the way he wanted to, and took a deliberate step away from my door, as if to say "move along, I won't be crawling in your room tonight." So went and brushed my teeth. I returned to my room passing the spider on the way. I would be long in bed before he reached his destination, whatever it may be, to dream that I too could move with the elegant glide of his eight-legged walk. |
posted Mar 23, 2010 6:34 AM by Daniel Marcus
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updated Mar 23, 2010 7:08 AM
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I wonder, sometimes, how it seems to have escaped everyone's notice that there is an easy way to install the latest version of Firefox on Ubuntu linux. Really. One that doesn't require an extra piece of software. One that does not require manual updates. One that works with the system. One that is stable.
I'm also not talking about installing the mozilla-daily PPA (which is as unstable as it sounds, and updates as often as it says). It turns out that the Ubuntu Mozilla Team has quietly released their own PPA.
This PPA provides (as of the time of this writing) Firefox 3.6 packaged for all Ubuntu releases from Hardy Heron up to Karmic Koala. It is a STABLE release, so it does not update all the time, and it provides all of Ubuntu's customizations, or at least, it is designed to work with them.
If you are running 9.10 (Karmic) or later, you have a simple option. Simply open your package manager of choice and add as a source: ppa:mozillateam/firefox-stable
You can also do this from the terminal by typing: sudo add-apt-repository ppa:user/ppa-name
That will add the correct line to the file, and also fetch the security key. If you are running something older than karmic, we'll go about this the old fashioned way. - Open a terminal, and type: "sudo nano /etc/apt/sources.list". You will need to enter your password.
- Arrow-down to the end of the file, and paste these lines:
#Firefox Stable PPA
deb http://ppa.launchpad.net/mozillateam/firefox-stable/ubuntu YOUR_UBUNTU_VERSION_HERE main
deb-src http://ppa.launchpad.net/mozillateam/firefox-stable/ubuntu YOUR_UBUNTU_VERSION_HERE main
Replace "YOUR UBUNTU VERSION HERE" with your appropriate version; hardy, intrepid, jaunty, or karmic.
- Press [Ctrl]+[x] to save the document. You will need to press "y" to save the changes.
- This takes care of adding the source, but we want it to authenticate. This provides some security. Still in your terminal, run the following:
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys ce49ec21
- After step four finishes, it will tell you it has imported the security keys. Now, update your system however you feel comfortable.
"sudo apt-get update; sudo apt-get upgrade" is a one-liner that can get the job done from the terminal. You will now be running Firefox 3.6, or whatever the latest version by the Mozilla team is.
This is the method I use myself for keeping my computers up to date. I have found it to be effective, and stable. I've used both the daily builds before, and Ubuntuzilla. Both are great for specific purposes, but when it comes to something that fills the "no hassles" ideal, this way tends to work the best. |
posted Feb 17, 2010 12:53 PM by Daniel Marcus
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updated Feb 17, 2010 2:33 PM
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It's the worst case scenario. One guy to the right is drinking a Cola and staring blankly (perhaps longingly) at the door. Personally, I am amusing myself by taking interest in sweeping wrinkles of the overhead projector screen. Speaking of which, it's a real overhead, not an LCD projector. About half the people in the class brought a copy of the questions we are going over, and the sketches of price and demand curves on the board look more like modern art than anything else. Even the printout of answers for the test seems stuck in the past, printed in some ancient typewriter font with dashes and equals signs present to line things up and divide the page. There is but one paper taped to the wall. It's hung on a phallic structure which the paper labels "Momentum Probe". The most interesting thing in the room, and It's not even related to the class. There is a teacher, he's talking somewhere near the front of the room. I'll get to him in a moment.
So what is the use of a class? A class is a place to learn. A place where you gain knowledge in a formal environment and in such a way that it is a more efficient option than other ways you could learn the same material. Perhaps the most important factor in any class is how actually useful it will be in life. Anything can be useful. In music class in elementary school, I learned the names of the 50 states in America, I learned the proper way to shake a hand. In my introduction to materials and processes, I learned how to weld and solder, the kind of skills that will almost certainly come in handy one day when I want to fix something myself instead of paying someone else. A class should help you learn and make you think.
I did, however, say that I would get back to the teacher of that class I was talking about earlier. In an effort to save the class, the teacher decided it would be a good idea to amuse us with a story of two economists and poop. The story starts with two economists, creatively named "A" and "B" who have just finished eating dinner. The friends come upon two large poops. Economist "A" dares economist "B" to eat one of the poops for a million dollars, which he proceeds to do.
Now, at this point, one of the guys sitting next to me and I connect for a moment. Without so much as raising an eyebrow, we effectively communicate to each other something along the lines of "What is this shit?" I mean seriously, why are we talking about economists who eat poop?
It turns out after eating his dessert (the teacher was having trouble keeping the terms "poop" and "dessert" straight) economist "B" doesn't feel very well, so to get back at economist "A" he dares him to eat the other poop/dessert, and he'll give him back the million dollars, which he does upon "A" eating the second poop/dessert.
After a short discussion on GDP, I have learned a few things from this. - Economists think they can raise the national GDP by eating poop
- The result of economists eating poop is to raise the Gross Domestic Product by two poops
- Economists are likely to become extinct due to high levels of poop in their diets
- My teacher's stories are full of shit
Other than that, I personally believe that poop is better flushed down the toilet. |
posted Feb 16, 2010 6:26 PM by Daniel Marcus
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updated Feb 16, 2010 7:31 PM
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Google Buzz is cool, but perhaps the biggest thing it has done for me is to remind me that I sometimes have dumb little thoughts I want to share. I don't want to flood Buzz with longer anecdotes, so instead, I shall opt for finally setting up a little Blog. Google Sites is a great tool, and it's only gotten better with time.
This is what I had posted on Buzz: Thank God for small miracles. Today on the bus the driver was feeling particularly stop-and-go. There was not enough room for everyone to sit. Despite two people at separate times falling into me, I somehow managed to not fall into anyone else, nor to spill my very full cup of very hot coffee. Considering that I am the embodiment of the term "klutz" most of the time, I believe this to be divine intervention.
See? Just a bit longer than is appropriate for Buzz.
Well, now I have a place to share some thoughts- watch out World!
Also, I just competed in a not-so-small movie making competition. I'll let them put a high quality version on Youtube, but if you want, you can check it out here: Four Stories |
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