Crop/trim a JPG file with empty space with Java

Question

Is there a framework which is able to remove the white space (rectangular) of an image. We create Image Thumbnails from technical drawings which are unfortunately in PDF for

Answer 1

For Android users, here is an example using Mike Kwan Answer:

    public static Bitmap TrimImage(Bitmap bmp) {
    int imgHeight = bmp.getHeight();
    int imgWidth  = bmp.getWidth();

    //TRIM WIDTH
    int widthStart  = imgWidth;
    int widthEnd = 0;
    for(int i = 0; i < imgHeight; i++) {
        for(int j = imgWidth - 1; j >= 0; j--) {
            if(bmp.getPixel(j, i) != Color.TRANSPARENT &&
                    j < widthStart) {
                widthStart = j;
            }
            if(bmp.getPixel(j, i) != Color.TRANSPARENT &&
                    j > widthEnd) {
                widthEnd = j;
                break;
            }
        }
    }
    //TRIM HEIGHT
    int heightStart = imgHeight;
    int heightEnd = 0;
    for(int i = 0; i < imgWidth; i++) {
        for(int j = imgHeight - 1; j >= 0; j--) {
            if(bmp.getPixel(i, j) != Color.TRANSPARENT &&
                    j < heightStart) {
                heightStart = j;
            }
            if(bmp.getPixel(i, j) != Color.TRANSPARENT &&
                    j > heightEnd) {
                heightEnd = j;
                break;
            }
        }
    }

    int finalWidth = widthEnd - widthStart;
    int finalHeight = heightEnd - heightStart;

    return Bitmap.createBitmap(bmp, widthStart,heightStart,finalWidth, finalHeight);
}

Hope this help someone :)

EDIT:

Guys, I just updated my answer cuz last code was just trimming the end of the image, not the beginning. This one is working just great :)