Re: Image Thinning using JAVA

Knute Johnson <>
Tue, 26 Jun 2012 14:26:45 -0700
On 6/26/2012 9:50 AM, sumera wrote:

I have written some code in java to convert a colored image into black and white image and then tried to perform thinning on that gray-scale image. Black and white conversion is done successfully, but image thinning is still not giving correct output. Kindly help me in fixing my problem. My code is as follows:

//colored image to black and white conversion; black and white image to thinned image.

public static void main(String[] args)
         //colored image path
         BufferedImage colored_image = File("D:\\logo.jpg"));
         //getting width and height of image
         double image_width = colored_image.getWidth();
         double image_height = colored_image.getHeight();
         BufferedImage img = colored_image;

         //drawing a new image
         BufferedImage bimg = new BufferedImage((int)image_width, (int)image_height, BufferedImage.TYPE_BYTE_GRAY);
         Graphics2D gg = bimg.createGraphics();
         gg.drawImage(img, 0, 0, img.getWidth(null), img.getHeight(null), null);

         //saving black and white image onto drive
         String temp = "logo in blackAndwhite.jpeg";
         File fi = new File("D:\\" + temp);
         ImageIO.write(bimg, "jpg", fi);

         //thinning by resizing gray scale image to desired eight and width
         BufferedImage bimg2 = new BufferedImage((int)image_width, (int)image_height, BufferedImage.TYPE_INT_ARGB);
         Graphics2D g2 = bimg2.createGraphics();

         // Perform your drawing here
         g2.drawLine(0, 0, 200, 200);

        //saving thinned image onto drive
        String temp2 = "logo thinned.jpeg";
        File fi2 = new File("D:\\" + temp2);
        ImageIO.write(bimg2, "jpg", fi2);
     catch (Exception e)

     public static BufferedImage convertToGray(BufferedImage image) {
         BufferedImage gray = new BufferedImage(image.getWidth(),
         ColorConvertOp op = new ColorConvertOp(
         return gray;

You can use the same technique as above with an AffineTransformOp, as
John Matthews mentioned, to scale an image.


Knute Johnson

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