AT-200CL
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Fig.14. Variable Partial scan
How to calculate total line number and frame rate in variable partial scan mode
Frame rate (fps) = Horizontal frequency(25.432KHz) / Total lines
Total lines = OB Fast Dump period in the upper part of the frame (L) +
Effective image period (L) + Fast dump period in the lower part of frame(L)
+ Blank period (L)
Where,
OB period = 4L (Fixed)
Blank period = 5L (Fixed)
Fast dump period for the upper part =
(
)
Fast dump period for the lower part =
(
)
Calculation example
Read out: 1/2 partial at the center (621L), Start line (308), End line (928)
OB period = 4L
Blank period = 5L
Fast dump period for the upper part = (5+308-1)
÷
7 +1= 44.57 + 1 = 45.57
46
Fast dump period for the lower part = (1236-928+2)
÷
7 =44.2
45
Total lines = 4+5+46+621+45=721
Frame rate = 25,432/ 721 =35.27 fps
Image Height
Image start
line/end line
Minimum: 2 lines
Maximum: 1236 lines
Image start line from 1 to 1235
Image end line from 2 to 1236
1/2
1235/
2 lines
1236 lines
1236
Image start line from 1 to 1235
Image end line from 2 to 1236
