Plotting RGB spectrum as 2-d color matrix?

Question

Any suggestions on how I might go about plotting the RGB color space as a 2-D matrix? I need a theoretical description of what's going on; a code sample or pseudocode would be helpful but is not required. Thanks!

Answer 1

If you want to represent every color in RGB space in a 2D grid, it may be impossible to avoid discontinuities / sharp borders in the result. But some mapping techniques will look better than others.

Examples from Possiblywrong.wordpress.com post allRGB: Hilbert curves and random spanning trees:

• Traverse the pixels of the image via a 2-dimensional (order 12) Hilbert curve, while at the same time traversing the RGB color cube via a 3-dimensional (order 8) Hilbert curve, assigning each pixel in turn the corresponding color 2D">

• "Breadth-first traversal of random spanning tree of pixels, assigning colors in Hilbert curve order."

Also check out allrgb.com, "The objective of allRGB is simple: To create images with one pixel for every RGB color (16777216); not one color missing, and not one color twice."

Answer 2

If you don't want to lose any information, you will need to use three dimension. If you can lose some dimensional information, then it's easy. Just do this:

// or HSV
int [256*256][256] colorMatrix;
for (int r = 0; r < 256; r++) {
    for (int r = 0; r < 256; r++) {
        for (int r = 0; r < 256; r++) {
            colorMatrix[256*r+g][b] = color(r, g, b);
        }
    }
}

Answer 3

There isn't really a good answer for 2D, because you really need 3 dimensions. Of course, you can project a 3D space onto 2D, but to retain a meaningful amount of information you nearly need to provide the normal 3D manipulation, so you can see the projection viewed from various different angles and such.