code: public static void normalize(GrayF32 image , float mean , float stdev ) {
  		for (int y = 0; y < image.height; y++) {
  			int index = image.startIndex + y*image.stride;
  			int end = index + image.width;
  			while( index < end ) {
  				image.data[index] = (image.data[index]-mean)/stdev;
  				index++;
  			}
  		}
  	}
docs: Normalizes a gray scale image by first subtracting the mean then dividing by stdev.
  @param image Image that is to be normalized
  @param mean Value which is subtracted by it
  @param stdev The divisor