changing colors

[bab javier]

hello again!
let's say I have a png file and I want to change all the red colors to another color. is it possible? what's the code?
tnx again guys

[Lasse Koskela]

let's say I have a png file and I want to change all the red colors to another color. is it possible? what's the code?

Where are you processing the image? I don't know how to do that in the mobile, but on the server-side you can use Java Advanced Imaging for manipulating the PNG image.
Here's my attempt to code a sample using the JAI API (not compiled, no guarantees of any sort):

import java.awt.image.renderable.ParameterBlock;
import javax.media.jai.RenderedOp;
// Create a ParameterBlock for the JAI create method
InputStream instream = new FileInputStream("image.png");
ParameterBlock pb = new ParameterBlock();
pb.add(instream);
// Create the PNG operation.
RenderedOp op = JAI.create("PNG", pb);
// We're done reading the image file
instream.close();
// Manipulate the image in-memory
WritableRaster raster = op.copyData();
int height = raster.getHeight();
int width = raster.getWidth();
for (int row = 0; row < width; row++) {
    for (int col = 0; col < height; col++) {
        int[] old = raster.getPixel(row, col, null);
        if (old[0] == 255 && old[1] == 0 && old[2] == 0) {
            // this pixel is red --> let's convert it to blue
            int[] new = new int[] { 0, 0, 255 };
            raster.setPixel(row, col, new);
        }
    }
}
// write the image back to disk
OutputStream outstream = new FileOutputStream("image.png");
PNGEncodeParam param = new PNGEncodeParam();
ImageEncoder encoder = ImageCodec.createImageEncoder("PNG", outstream, param);                           
encoder.encode(op);
outstream.close();

[bab javier]

hi! thanks for the tip.
i have to change it in the mobile. its part of a game that i'm developing