Native Moiré on computer screens > Pattern Generator.
One of the most interesting cases whilst testing the Pattern Generator is loading up a pattern consisting of pure RGB stripes (This is included as a sample pattern when you download the application).
This is virtually the same as how an LCD display displaying a full white would look like if you zoom close enough, minus the space between each pixel:
|The pattern||How it really looks like on the LCD display|
Loading this pattern into the Pattern Generator, I expect to see a spectrum of colours, for the image redraw algorithm tends to average the values within the range of pixels it has to squeeze into one single pixel. And here is what I get, with interpolation/anti-aliasing off:
|Cyan, Magenta & Yellow!||Cyan = G+B; Magenta = R+B; Yellow = R+G|
On closer inspection, your eyes are fooling you. They are still R,G,B stripes. in a different configuration due to the reduction algorithm.
You get even more dramatic effects when you turn interpolation on, and I was right about the perceptive spectrum of colours:
|Beautiful, isn't it?||Colour stripes are still basically RGB, but averaged|
Interpolation averaged the colours on the image and we now have a smooth transition from across the hue range.
Ed: for some reason, the above images will look rather dull on CRT displays, especially the magenta range, but look bright on LCD displays.
© Edmund Fung | firstname.lastname@example.org