Description

This is a small collection of test screens that I put together for testing colors, contrast, and so forth on computer screens. I built this tool to assist with my home theater design. Specifically, for testing my home made LCD projector (see Lumenlab). I couldn't find any existing software that did full screen test patterns on a Mac or Linux, so I did what I usually do in these situations. I made my own.

Usage

Since testPattern is web based, it's totally cross platform. It should work under any browser, and is meant to be used in full-screen mode. To do this on most computers, just open the testPattern window in your browser and hit F11. Getting true full screen on a Mac is something of a chore, however, you can use MegaZoomer with Safari to easily get the results you're looking for.

Once you have it up, simply use the left and right arrow keys to scroll through the screens. The escape key will close the testPattern window. That's it.

Screens

Most of testPattern's screens are very easy to use. Just look at them and see if the image looks right.

• Focus Grids: These are exactly what they sound like; a collection of grids and concentric circles to help you focus a projection.
• Screen Sizes: This image shows a collection of standard screen sizes at different aspect ratios. The white box in the center is 640x480. The yellow boxes are other typical 4:3 resolutions, and Blue boxes are 16:9 "hi-def" resolutions (at vertical lengths of 480, 720, and 1080).
• Pin Stripes: The pin stripe lines are alternating 1px black and white lines, horizontal in one image, vertical in another. On some monitors, these screens will appear to be all gray. These images can be used for focusing, and for determining pixel size in a projection.
• Gradients: There are a number of gradient images, for each of the primary and secondary colors, running black to color to white, in each screen direction. There are also black-white gradients in each direction. These images are helpful for determining if your screen is prone to color banding.
• Contrast Boxes: A combination of gradients and compilmentary colors, these screens each display a grid of 441 different color contrasts. All but two of these boxes (the upper right and lower left) should be easily distinguishable.

Color bars

The only screen in testPatten that requires you to actually do something for testing is the color bars screen. It's the first one up. It looks like your standard NTSC color bars, but I wouldn't try to sync to it. The reason that this particular pattern is used is because of how you can test your image with it.

Adjust your image by removing and then re-adding various colors to it (turn red off, turn blue off, etc...). Since the image contains all six primary and secondary colors, as well as black and white (and a few shades of gray), some colors will change to others as you go. You should see the following patterns as you make adjustments.

Red off	Green off	Blue off
Red only	Green only	Blue only

Another adjustment you can make is to turn the contrast all the way up. This should eliminate the three gray boxes in the bottom row, and turn them all white.