Hi everyone! I've got a question concering a colormapping via index.

I tried this code found on

http://www.podgoretsky.pri.ee/ftp/Docs/Java/Tricks%20of%20the%20Java%20Programming%20Gurus/ch12.htm

// Gradient.java

// Imports import java.applet.Applet; import java.awt.; import java.awt.image.;

public class Gradient extends Applet { final int colors = 32; final int width = 200; final int height = 200; Image img;

public void init() { // Create the color map byte[] rbmap = new byte[colors]; byte[] gmap = new byte[colors]; for (int i = 0; i < colors; i++) gmap[i] = (byte)((i * 255) / (colors - 1));

// Create the color model
int bits = (int)Math.ceil(Math.log(colors) / Math.log(2));
IndexColorModel model = new IndexColorModel(bits, colors,
  rbmap, gmap, rbmap);

// Create the pixels
int pixels[] = new int[width * height];
int index = 0;
for (int y = 0; y < height; y++)
  for (int x = 0; x < width; x++)
    pixels[index++] = (x * colors) / width;

// Create the image
img = createImage(new MemoryImageSource(width, height, model,
  pixels, 0, width));

}

public void paint(Graphics g) { g.drawImage(img, 0, 0, this); } }

It worked great but I tried to load a custom image jpeg mapped on my own colormap but it didnt work right. I saw only a bunch of green and blue pixels drawn on a white background. My custom color map method here:

 public void inintByteArrays() {

double[][] c = // basic color map { { 0.0000, 0.0000, 0.5625 }, { 0.0000, 0.0000, 0.6250 }, { 0.0000, 0.0000, 0.6875 }, { 0.0000, 0.0000, 0.6875 }, { 0.0000, 0.0000, 0.7500 }, { 0.0000, 0.0000, 0.8125 }, { 0.0000, 0.0000, 0.8750 }, { 0.0000, 0.0000, 0.9375 }, { 0.0000, 0.0000, 1.0000 }, { 0.0000, 0.0625, 1.0000 }, { 0.0000, 0.1250, 1.0000 }, { 0.0000, 0.1875, 1.0000 }, { 0.0000, 0.2500, 1.0000 }, { 0.0000, 0.3125, 1.0000 }, { 0.0000, 0.3750, 1.0000 }, { 0.0000, 0.4375, 1.0000 }, { 0.0000, 0.5000, 1.0000 }, { 0.0000, 0.5625, 1.0000 }, { 0.0000, 0.6250, 1.0000 }, { 0.0000, 0.6875, 1.0000 }, { 0.0000, 0.7500, 1.0000 }, { 0.0000, 0.8125, 1.0000 }, { 0.0000, 0.8750, 1.0000 }, { 0.0000, 0.9375, 1.0000 }, { 0.0000, 1.0000, 1.0000 }, { 0.0625, 1.0000, 0.9375 }, { 0.1250, 1.0000, 0.8750 }, { 0.1875, 1.0000, 0.8125 }, { 0.2500, 1.0000, 0.7500 }, { 0.3125, 1.0000, 0.6875 }, { 0.3750, 1.0000, 0.6250 }, { 0.4375, 1.0000, 0.5625 }, { 0.5000, 1.0000, 0.5000 }, { 0.5625, 1.0000, 0.4375 }, { 0.6250, 1.0000, 0.3750 }, { 0.6875, 1.0000, 0.3125 }, { 0.7500, 1.0000, 0.2500 }, { 0.8125, 1.0000, 0.1875 }, { 0.8750, 1.0000, 0.1250 }, { 0.9375, 1.0000, 0.0625 }, { 1.0000, 1.0000, 0.0000 }, { 1.0000, 0.9375, 0.0000 }, { 1.0000, 0.8750, 0.0000 }, { 1.0000, 0.8125, 0.0000 }, { 1.0000, 0.7500, 0.0000 }, { 1.0000, 0.6875, 0.0000 }, { 1.0000, 0.6250, 0.0000 }, { 1.0000, 0.5625, 0.0000 }, { 1.0000, 0.5000, 0.0000 }, { 1.0000, 0.4375, 0.0000 }, { 1.0000, 0.3750, 0.0000 }, { 1.0000, 0.3125, 0.0000 }, { 1.0000, 0.2500, 0.0000 }, { 1.0000, 0.1875, 0.0000 }, { 1.0000, 0.1250, 0.0000 }, { 1.0000, 0.0625, 0.0000 }, { 1.0000, 0.0000, 0.0000 }, { 0.9375, 0.0000, 0.0000 }, { 0.8750, 0.0000, 0.0000 }, { 0.8125, 0.0000, 0.0000 }, { 0.7500, 0.0000, 0.0000 }, { 0.6875, 0.0000, 0.0000 }, { 0.6250, 0.0000, 0.0000 }, { 0.5625, 0.0000, 0.0000 }, { 0.5000, 0.0000, 0.0000 } };

for (int i = 0; i < c.length; i++) {

for (int j = 0; j < c[i].length; j++) { if (j == 0) r[i] = (byte) ((byte) c[i][j]*255); if (j == 1) g[i] = (byte) ((byte) c[i][j]*255); if (j == 2) b[i] = (byte) ((byte) c[i][j]*255); } }

My question is how I can use my colormap for any image I want to load and map in the right way. Thank you very much!

Greetings, protein1.