Extract foreground from binary image

Question

hi
i need help in java programming in java.
i have a binary image
by the code
BufferedImage image = ImageIO.read(new File("f:/123.JPG"));
BufferedImage bwImage = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_BYTE_GRAY);
//bwImage.createGraphics().drawImage(image, 0, 0, null);
BufferedImage bwImage1 = new BufferedImage(bwImage.getWidth(), bwImage.getHeight(), BufferedImage.TYPE_BYTE_BINARY);
//bwImage1.createGraphics().drawImage(image, 0, 0, null);
i need only foreground in color..can u give me the code for that..its urgent..

Answer 1

If you want any color whatsoever, then you need to use a BufferedImage type that supports color. BufferedImage.TYPE_BYTE_BINARY wont do. In the example below I use BufferedImage.TYPE_INT_RGB. The foreground remains in color, while everthing else turns white.
BufferedImage image = ImageIO.read(...);
        BufferedImage fgImage =                     //foreground image
                new BufferedImage(image.getWidth(),image.getHeight(),
                BufferedImage.TYPE_INT_RGB);
        for(int x = 0; x < fgImage.getWidth(); x++) {
            for(int y = 0; y < fgImage.getHeight(); y++) {
                int rgbSrc = image.getRGB(x, y);
                if(rgbSrc == rgbForeground) {
                    fgImage.setRGB(x,y,rgbForeground); //remain in color
                }else{
                    fgImage.setRGB(x,y,-1);  //set white
        }Or are you looking for more of a Sin City effect where one thing remains in color and everything else is in grayscale?
BufferedImage image = ImageIO.read(...);
        BufferedImage fgImage =                     //foreground image
                new BufferedImage(image.getWidth(),image.getHeight(),
                BufferedImage.TYPE_INT_RGB);
        for(int x = 0; x < fgImage.getWidth(); x++) {
            for(int y = 0; y < fgImage.getHeight(); y++) {
                int rgbSrc = image.getRGB(x, y);
                if(rgbSrc == rgbForeground) {
                    fgImage.setRGB(x,y,rgbForeground); //remain in color
                }else{
                    int r = (rgbSrc>>16)&0xff;
                    int g = (rgbSrc>> 8)&0xff;
                    int b = (rgbSrc    )&0xff;
                    int lum = (int) (.299 * r + .587 * g + .144 * b);
                    //set to grayscale
                    fgImage.setRGB(x,y,(255<<24)|(lum<<16)|(lum<<8)|lum);
        }