JAI AT-200GE - Manual (Page 31)

AT-200GE
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Fig.23 Variable Partial scan
 How to calculate total line number and frame rate in variable partial scan mode
Frame rate (fps) = Horizontal frequency(19.276KHz) / Total lines
Total lines = ①OB period + ②Fast Dump period in the upper part of the frame (L) +
③ Effective image period (L) + ④Fast dump period in the lower part of frame
(L) + ⑤Blank period (L)
Where,
OB period = 4L (Fixed)
Blank period =4L (Fixed)
Fast dump period for the upper part = Round up
6+Start line −1
9
+ 1
Fast dump period for the lower part = Roud up
1236−End line +2
9
Calculation example
Read out: 1/2 partial scan at the center (616L), Start line (311), End line (926)
OB period = 4L
Blank period =6L
Fast dump period for the upper part = (6+311-1) ÷9 +1= 35.1 + 1=36.1  37
Fast dump period for the lower part = (1236-926+2) ÷ 9 =34.6  35
Total lines = 4+37+616+35 +4 = 696
Frame rate = 19.276/ 696 =27.69 fps
Image Height
Image start line
/ end line
Minimum: 8 line Maximum: 1236 lines
Image starts at 1st line
Image starts at 1229th line
This is in case image height is 8 line
1/8
1229
/1236
8 line
1236 lines