This is the command to start the calibrator:
dispcal -v -y l -g 2.2 -t 6500 -q h target
There are a few options that can be set in this command by changing the values after the option flags (the dash followed by a letter):
Monitor type: -y l for LCD displays, -y c for CRT displays
Target gamma: -g (gamma) Lets you specify a target gamma, use 2.2 unless you know why you should pick otherwise.
Colour Temperature: -t (temperature in Kelvins) Lets you adjust the target white point. Most people should choose 6500, those working with print or graphic art may prefer a warmer white; 5000-6000.
Calibration quality: q (l, m, or h) Choose low, medium, or high calibration quality. Higher settings take longer to read. Medium is fine for most purposes, but high may be desired for a more accurate profile.
First we want to adjust the white point of the display. If you're on a laptop, you can skip this step since there are no colour controls.
Choose 2) White point (Color temperature, R,G,B, Gain/Contrast)
The square will flash different colours for a second then you'll see something like this at the bottom of the window:
/ Current Br 102.33, x 0.3175, y 0.3403 DE 6.0 R- G-- B+
Find your monitor's custom colour settings and adjust the Red, Green, and Blue settings so that the number after DE is as low as you can get it. Follow the symbols after RGB at the bottom of the window; if there are two minus symbols after G, then you need to reduce the amount of green. When finished, hit the space bar. If your monitor lacks custom colour settings, set its temperature setting as close as possible to the colour temperature you picked above
Now we want to adjust the brightness of the monitor:
Choose 3) White level (CRT: Gain/Contrast, LCD: Brightness/Backlight)
The program will display the monitor's current brightness in cd/m2. Adjust the Brightness setting (or contrast on a CRT) to change the brightness to the desired level. The optimal level depends mainly on the ambient lighting. If your room is very dark, you can get better colour by lowering the brightness to 90 or 100 cd/m2. For most people, 110-120 cd/m2 is a good range. If your room is really bright, you should consider buying a hood to shade your monitor. If you can't raise the brightness setting high enough, you may have to go back a step and increase all of the RGB settings. Hit space to return to the menu.
Now to begin the calibration:
Choose 7) Continue on to calibration
generating and reading target patches
targen -v -d 3 -f 1500 display
The only option is the number of patches to generate: -f (number of patches). The more patches you generate, the better your profile will be in the end, but more patches take longer to read. For most people between 300-500 patches are adequate. If you want a very accurate profile, or are using a device that has a complicated colour response, or even if you just have some extra time, 1500-2000 patches is not unreasonable.
To start reading the patches, type the following command:
dispread -y l -v -k target.cal display
The -y option is the same as for dispcal; set it to c if using a CRT, otherwise set it to l.
generating your ICC profile
colprof -v -D Display Name -q h -a s display
Quality -q (l, m, or h): Sets the profile quality. Choosing high here doesn't add too much extra time to process, so you might as well always use it.
Profile Type (s or l): Choose between matrix/shaper profile (s) and LUT profile (l). LUT profiles are more accurate, but need at least 1000 patches read to produce a good result, for fewer patches, choose a matrix/shaper profile.
After the command has finished, you'll have an ICC profile of your monitor sitting in your Argyll/bin/ folder, named name.icc (or .icm depending on your operating system). You can use it like that, but it's usually better to install it with your other profiles on your system.
To load the profile, simply type:
dispwin -I path/to/name.icc