SECTION 6.4
501
Halftones
X
*
* *
* *
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
Y
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
* *
* *
*
FIGURE 6.3
Angled halftone cell divided into two squares
Y
X
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
b
b
c
c
c
c
a
a
a
a
a
a
b
b
b
b
c
c
c
c
c
c
c
c
a
a
a
a
b
b
b
b
b
b
c
c
c
c
c
c
a
a
b
b
b
b
b
b
b
b
c
c
c
c
b
b
b
b
b
b
b
b
b
b
c
c
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
X
Y
Y
X
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
*
b
b
b
b
b
b
b
b
c
c
c
c
c
c
c
c
c
c
*
c
c
c
c
c
c
Y
FIGURE 6.4
Halftone cell and two squares tiled across device space