public BufferedImage showBitPlanes(BufferedImage bi, int lv)
	{
		int level = 0;
		
		switch(level)
		{
			case 0:
				level = 128;
				break;
			case 1:
				level = 64;
				break;
			case 2:
				level = 32;
				break;
			case 3:
				level = 16;
				break;
			case 4:
				level = 8;
				break;
			case 5:
				level = 4;
				break;
			case 6:
				level = 2;
				break;
			case 7:
				level = 1;
				break;
			default:
					return null;
		}
		
		int width = bi.getWidth();
		int height = bi.getHeight();
		
		BufferedImage img = new BufferedImage(width, height, bi.getType());
		
		for(int x=0; x<width; x++)
			for(int y=0; y<height; y++)
				img.setRGB(x, y, ((bi.getRGB(x, y) & level)/level)*255);
		
		return img;
	}

% Ritorna i Bit Plabes dell'immagine a toni di grigio

function showBitPlanes(img)

    imgGray = double( rgb2gray(img) );
    titleString = 'bit planes ';
    
    % MSB ... LSB
    k = 128;
    
    for b=1:8
        
        subplot(2, 4, b);
        imshow( (bitand(imgGray, k) / k) * 255 ); % Fa un and dei bit
        title([titleString int2str(b-1)]);
        k = k/2; % Shifta di 2 i bit
        
    end;
    
return;