A Little Off Code, Computers, Photography and Guns

Analog Monitor Calibration

Many of you probably already are aware that LCD Monitors typically will come with an analog VGA port^[1] but the typical way that LCD Monitors work is that they reference individual pixels to draw something where CRT's use a scanning electron beam to illuminate pixels. Because of the way this works LCD Monitors usually come with an "Auto" button or "Auto-calibrate" which will align the analog image to the displayable area of the monitor. But doing this with just any image won't always give you the sharpest alignment and calibration.

The method I've used for quite some time is a program that generates a black and white cross-hatch that basically makes a checkerboard of every single pixel on the screen. This makes it very easy for the auto-calibration feature of the monitor to almost exactly align the image to exact pixels. The program i use to do this is called lcdtest^[2]. There are even windows binaries^[3] that can be found by digging through the page, I've provided a link in the footnotes to the page I usually get them from.

The program starts and immediately draws the test pattern on the entire screen. You'll want to press w to change the color to white on black. Then you'll want to press x to change the pattern to crosshatch. Then using the - key to zoom out until it looks nearly grey. This is a good point at which you can see how well your monitor is calibrated already. If it looks very grey this is a sign that the scanning frequencies may not be exact, you might also see waves where it's clear and areas where it is blurry, these will likely go away once we're done. At this point you should use the auto-calibration feature of your monitor to calibrate the display using the crosshatch being displayed.

For those of you running more than one monitor at a time, this program will only display the pattern on the primary monitor. But never fear, there is an easy fix. Using paint or paint.net or your favorite image editing program you can create an image of the test pattern and set it as the wallpaper for the other monitors and calibrate them as well. Using Alt+PrtScn to capture only the current application's area of the screen (the test pattern) and pasting into a new image you can then save the image as a png^[4] preferably as it will compress it losslessly.

Once you've saved the image simply set it as the wallpaper of your system and use tiling in the case that your other monitor is not the same dimensions as your primary monitor and then run the auto-calibration process on the remaining monitors. You'll find that this will significantly improve the quality of the image displayed on your monitors if they were improperly calibrated to begin with. But of course you could completely avoid this by switching to DVI^[5]

1. [W: VGA_connector] [↩]
2. http://www.brouhaha.com/~eric/software/lcdtest/ [↩]
3. http://code.google.com/p/lcdtest-win32/ [↩]
4. [W: Portable_Network_Graphics] [↩]
5. [W: Digital_Visual_Interface] [↩]