Creating an IndexColorModel with 8 Colours

[Mikpo Siru]

Hi,

I want to make an IndexColorModel object with 8 colours: red, green, blue, cyan, magenta, yellow, white, black.

I think the constructor below is the one that I need, but I don't know how to continue. Any help is appreciated.

public IndexColorModel(int bits,
                       int size,
                       byte[] cmap,
                       int start,
                       boolean hasalpha)

Thanks.

[Darryl Burke]

I take it that this is in continuation of http://www.coderanch.com/t/504019/GUI/java/Suggestions-colour-convertor-program and in response to my suggestion there.

Since you apparently didn't feel the need to acknowledge that the suggestion could be useful to you, I don't feel like guiding you further.

To the Bartenders: If you feel this is unduly harsh and violates the principles of BeNice, please feel free to remove it.

[Mikpo Siru]

Hi,

I have updated the above mentioned thread.

The documentation gives these parameter descriptions:

public IndexColorModel(int bits,
                       int size,
                       byte[] cmap,
                       int start,
                       boolean hasalpha)

    bits - the number of bits each pixel occupies
    size - the size of the color component arrays
    cmap - the array of color components
    start - the starting offset of the first color component
    hasalpha - indicates whether alpha values are contained in the cmap array 

The images that I want to represent using IndexColorModel will be user-selected, so the image dimensions are not fixed. If it makes things much simpler, I can restrict the user to selecting an image of a fixed format, such as only GIF or only JPEG.

The eight colours I want the IndexColorModel to have are: red, green, blue, cyan, magenta, yellow, white, black.

Could anyone please explain what the parameters mean in this case? Then I can try filling them in.

Thanks.

[Darryl Burke]

Snippets from the code I used for proof of concept:

Color[] colors = {Color.red, Color.green, Color.blue,
    Color.cyan, Color.magenta, Color.yellow,
    Color.white, Color.black};
    byte[] reds = new byte[8];
    byte[] greens = new byte[8];
    byte[] blues = new byte[8];
    for (int i = 0; i < colors.length; i++) {
      reds[i] = (byte) colors[i].getRed();
      greens[i] = (byte) colors[i].getGreen();
      blues[i] = (byte) colors[i].getBlue();
    }
    IndexColorModel cm = new IndexColorModel(3, 8, reds, greens, blues);
    // 'image' is the converted image, bi is read from disk
    image = new BufferedImage(bi.getWidth(), bi.getHeight(), BufferedImage.TYPE_BYTE_INDEXED, cm);

[Mikpo Siru]

Thanks! This was the main component in the converter program I was writing, so I have updated that thread: http://www.coderanch.com/t/504019/GUI/java/Suggestions-colour-convertor-program#2277917