118 
Six scan pixels were selected from the 72 nd and 73 rd row 
of the pixmap and they are decreased in one case (67% 
zoom out) and increased in two cases (170% and 800% 
zoom in). 
pixels and screen pixels is more complex than it may 
appear to be at the first glance. 
So, for example, raster graphics are not shown on the 
Pixmap 
17" screen with shadow mask 
640x480 (a=0,22, b=0,15, a 
co 
CO 
o' 
ll 
co 
ll 
N = 0,67 
(67%-decrease) 
N = 1,7 
(170%-lncrease) 
N = 8 
(800%-increase) 
x 
f(x) 
g(y) 
u 
v 
f(x) 
g(y) 
u 
V 
f(x) 
g(y) 
u 
v 
P 51,73 
2x2/2= 
4x5/2= 
17x26/2= 
2 Pixel 
10 Pixel 
221 
Pixel 
A 
50 
72 
/3,97 
156,22 
73 
156 
187,69 
396,39 
187 
396 
883,23 
1865,38 
883 
1865 
B 
51 
73 
/5,45 
158,4C 
75 
158 
191,44 
401,90 
191 
401 
900,89 
1891,28 
900 
1891 
P5273 
1 x2/2= 
4x5/2= 
18x26/2= 
1 Pixel 
10 Pixel 
234 Pixel 
A 
51 
72 
75,45 
156,22 
75 
156 
191,44 
396,39 
191 
396 
900,89 
1865,38 
900 
1865 
B 
52 
73 
76,93 
158,40 
76 
158 
195,19 
401,90 
195 
401 
918,56 
1891,28 
918 
1891 
P5373 
2x2/2= 
3x5/2 
=7,5 
18x26/2= 
2 Pixel 
8 Pixel 
234 Pixel 
A 
52 
72 
76,93 
156,22 
76 
156 
195,19 
396,39 
195 
396 
918,56 
1865,38 
918 
1865 
B 
53 
73 
78,40 
158,40 
78 
158 
198,95 
401,90 
198 
401 
936,22 
1891,28 
936 
1891 
P5174 
2x2/2= 
4x6/2= 
17x26/2= 
2 Pixel 
12 Pixel 
221 
Pixel 
A 
50 
73 
73,97 
158,40 
73 
158 
187,69 
401,90 
187 
401 
883,23 
1891,28 
883 
1891 
B 
51 
74 
75,45 
160,56 
75 
160 
191,44 
407,40 
191 
407 
900,89 
1917,19 
900 
191/ 
P5274 
1x2/2= 
4x6/2= 
18x26/2= 
1 Pixel 
12 Pixel 
234 Pixel 
A 
51 
73 
75,45 
158,40 
75 
158 
191,44 
401,90 
191 
401 
900,89 
1891,28 
900 
1891 
B 
52 
74 
76,93 
160,56 
76 
160 
195,19 
407,40 
195 
407 
918,56 
1917,19 
918 
1917 
P5374 
2x2/2= 
3x6/2= 
18x26/2= 
2 Pixel 
9 Pixel 
234 Pixel 
A 
52 
73 
76,93 
158,40 
76 
158 
195,19 
401,90 
195 
401 
918,56 
1891,28 
918 
1891 
B 
53 
74 
78,40 
160,56 
78 
160 
198,95 
407,40 
198 
407 
936,22 
1917,19 
936 
1917 
Table 10: Presentation of the translation of pixmap => screen at a decrease (zoom out 67%) 
and increase (zoom in 170% and 800%) on the example of a 17” screen with shadow mask. 
Upon the introduction of the half-row coordinate system, 
the apertures of the shadow mask are found only in every 
second field of rows and columns. Since each aperture on 
the shadow mask corresponds to one screen pixel, it is 
necessary to re-calculate the half-row fields into actual 
screen pixels. This re-calculation is performed according 
to the following rule: 
(number of columns * number of rows) / 2 = number of 
screen pixels 
Exception: (odd number of columns * odd number of 
rows) / 2 = .5 
1. example: (1 * 1 ) / 2 = 0.5 
- or 1 screen pixel; 
- or none screen pixel (when (x + y) of the lower left 
corner is an even number). 
2. example: (3 * 3) / 2 = 4.5 
- or 5 screen pixels 
- or 4 screen pixels (when (x + y) of the lower left corner is 
an even number). 
3. example: (Pixel P53,73, 170%; see Table 10): 
(198- 195) * 8401 - 396) / 2 = (3 * 5) / 2 = 7.5 
In this case the lower left corner is A’ (195, 396): (x + y = 
195 + 396 = 591). Therefore it must be rounded up higher: 
7.5 => 8 pixels. 
4. CONCLUSION 
From the considerations of the problem carried out so far, 
it becomes obvious that the interdependence of scan 
screen in their actual size. They change their size 
depending on the resolution and the size of the screen, 
because a scan pixel with a fixed form and size is being 
translated into a screen pixel whose form and size are 
changeable. 
Among other things, it is not recommendable to use 
screen resolutions higher than those corresponding to the 
mask apertures (dot pitch and aperture grill pitch) are, 
because it does not contribute to the quality of the image, 
especially not with the screens with a shadow mask 
(Malic, 1998). 
5. REFERENCE 
Foley, J.D., Dam, A. van, Feiner, S.K., Hughes, J.F., 
Philips, R.L., 1994. Grundlagen der Computergraphik: 
Einführung, Methodne, Prinzipien - 1. Aufl., Addison- 
Wesley, Bonn, Paris. 
Lang, H., 1995. Farbwiedergabe in den Medien: 
Fernsehen, Film, Druck, Muster-Schmidt Verl., Göttingen, 
Zürich, 
Malic, B., 1998. Physiologische und technische Aspekte 
kartographischer Bildschirmvisualisierung, Diss. Schrift 
Univ. Bonn, SIKB Heft 25. 
Moers, S., Theißing, F., 1996. Der richtige Bildschirm. 
Marktübersicht über strahlungarme, ergonomisch 
empfehlenswerte Computerbildschirme, DGB 
Technologieberatung e.V., Berlin.