Fundamentals of Digital Image Processing - Control of Color Imaging Systems: Analysis and Design - page 87

FIGURE 2.57 Halftone screen.

FIGURE 2.58 Halftone image.

2.10.1 E RROR D IFFUSION A LGORITHM
The block diagram of error diffusion algorithm is shown in Figure 2.59. The halftone
image is obtained by quantizing y ( n, m )

to 1 bit. The quantization error signal e ( n, m )
is diffused to the neighboring pixels by the LPF h ( n, m ) .

The signal y ( n, m ) is given as

y ( n, m ) ¼ f ( n, m ) e ( n, m ) * h ( n, m )
¼ f ( n, m )

X X

h ( i, j ) e ( n i, i,m j ) ( 2 : 145 )

j i

where e ( n, m ) ¼ g ( n, m ) y ( n, m ) .