a matrix that is applied over each virtual camera and forms a filter. His Matrix has been incorporated into many anaglyph programs such as StereoPhoto Maker () and threeJs's anaglyph effect () Anaglyphic color channels Anaglyph images may use any combination of color channels. However, if a stereoscopic image is to be pursued, the colors should be diametrically opposed. Impurities of color channel display, or of the viewing filters, allow some of the image meant for the other channel to be seen. This results in stereoscopic double imaging, also called ghosting. Color channels may be left-right reversed. Red/cyan is most common. magenta/green and blue/yellow are also popular. Red/green and red/blue enable monochromatic images, especially red/green. Many anaglyph makers purposely integrate impure color channels and viewing filters to enable better color perception, but this results in a corresponding degree of double imaging. Color channel brightness % of white: red-30/cyan-70, magenta-41/green-59 or especially blue-11/yellow-89), the lighter display channel may be darkened or the brighter viewing filter may be darkened to allow both eyes a balanced view. However the Pulfrich effect can be obtained from a light/dark filter arrangement. The color channels of an anaglyphic image require pure color display fidelity and corresponding viewing filter gels. The choice of ideal viewing filters is dictated by the color channels of the anaglyph to be viewed. Ghosting can be eliminated by ensuring a pure color display and viewing filters that match the display. Retinal rivalry can be eliminated by the (ACB) 3-D Anaglyphic Contrast Balance method patented by that prepares the image pair prior to color channeling in any color. In theory, under trichromatic principles, it is possible to introduce a limited amount of multiple-perspective capability (a technology not possible with polarization schemes). This is done by overlapping three images instead of two, in the sequence of green, red, blue. Viewing such an image with red-green glasses would give one perspective, while switching to blue-red would give a slightly different one. In practice, this remains elusive as some blue is perceived through green gel and most green is perceived through blue gel. It is also theoretically possible to incorporate rod cells, which optimally perform at a dark cyan color, in well-optimized mesopic vision, to create a fourth filter color and yet another perspective; however, this has not yet been demonstrated, nor would most televisions be able to process such tetrachromatic filtering. Applications On April 1,