GreyScale to Black and White

Question

Hey,
I'm having a few problems converting a grey scale BufferedImage to black and white. I create the BufferedImage as greyscale:
Image image = Toolkit.getDefaultToolkit().createImage(source);
// Create a grayscale color model.
ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY);
int bits[] = new int[]{4};
ColorModel cm = new ComponentColorModel(cs, bits, false, false, Transparency.OPAQUE, DataBuffer.TYPE_BYTE);
WritableRaster raster = cm.createCompatibleWritableRaster(image.getWidth(null), image.getHeight(null));
// use the colour model to create the buffered image
BufferedImage bimg = new BufferedImage(cm, raster, false, null);
bimg.createGraphics().drawImage(image, 0, 0, null);I then do some processing on the image, but when i go to save it, i want it to be black and white to reduce the file size and allow for G3 TIFF compression. I was able to convert it to black and white, but the file size of the TIFF didn't really reduce to much. When I was saving the image as grey scale they averaged at about 600Kb, now with black and white they average at 500Kb, but they should be much lower. Here is how i convert them to BW:
byte[] darkLight = {(byte) 0xff, (byte) 0};
IndexColorModel blackAndWhite = new IndexColorModel(1, 2, darkLight, darkLight, darkLight);
BufferedImage bwImage = new BufferedImage(image.getImage().getWidth(null), image.getImage().getHeight(null), BufferedImage.TYPE_BYTE_BINARY, blackAndWhite);
bwImage.createGraphics().drawImage(image.getImage(), 0, 0, null);
image.setImage(bwImage);I was wondering if there is a more efficient way of doing this, i.e meaning a way to convert the image without creating a new one in memory. and also any information on why the image is still taking up so much space even though it if BW.

Answer 1

That code will work, but is there a way to do this conversion without creating a new bufferedImage, memory could be an issue, since i'm working with really large bufferedImages