Printing System Models - Control of Color Imaging Systems: Analysis and Design - page 598

Gaussian beam profile

9

8

7

6

5

4

3

2

1

0

-150 -100 -50 0

Microns

50 100 150

(b)

FIGURE 10.38 (continued) (b) Gaussian beam.

Example 10.1

Consider a halftone dot matrix Q(x) given by Equation 10.63 and as shown in
Figure 10.40 where the dimensions of the x - y axes are given in microns. The
matrix representing the halftone patch contains series of ones and zeros as shown
below:

2
4

3
5

01000000
11100000
11100000
01000000
00000010
00000111
00000111
00000010

Q(x) ¼ (10 : 63)

In this example, the resolution of the halftone dot is selected to be approximately
35 microns per pixel. However, to model the effect of the laser beam, the

resolution has to be enhanced to around 7 15 microns. This is done by upsam-

-

pling the laser pro five times per pixel for a 7 micron resolution.

We assume here that the laser beam is exposed at the center of each scan line
(Figure 10.41).
The lighter (highlighted) regions of Figure 10.40 re

le (Figure 10.38)

ect the pixels that need to
be exposed by the laser beam. This step is identical to converting the image to
ideal video on a simulation grid. The upsampling factor is usually chosen to be an
odd number. For an upsampling factor p¼ 5, we upsample each scan line ve