docs: public static void copy( int srcX , int srcY , int dstX , int dstY , int width , int height ,
  							 GrayF32 input , GrayF32 output ) {
  
  		if( input.width < srcX+width || input.height < srcY+height )
  			throw new IllegalArgumentException("Copy region must be contained input image");
  		if( output.width < dstX+width || output.height < dstY+height )
  			throw new IllegalArgumentException("Copy region must be contained output image");
  
  		for (int y = 0; y < height; y++) {
  			int indexSrc = input.startIndex + (srcY + y) * input.stride + srcX;
  			int indexDst = output.startIndex + (dstY + y) * output.stride + dstX;
  
  			for (int x = 0; x < width; x++) {
  				output.data[indexDst++] = input.data[indexSrc++];
  			}
  		}
  	}