Quote:
Originally Posted by scharfis_brain
Aspect Ratio Correction is far more 'complicated' than you might imagine.
640 pixels actually translate to 702 pixels.
This also means that 720x480 after aspect ratio correction are 657x480 pixels.
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Thanks, based on your posting I have searched for more information and stumbled upon this website (in German):
http://www.dma.ufg.ac.at/app/link/Gr...step=1#chapter
So here is what I learned:
NTSC has 480 horizontal lines. With square pixels and an aspect ratio of 4:3 a frame with a height of 480 pixels would be 640 pixels wide. A digitized 4:3 NTSC frame however is defined to be 702 pixels wide with non-square pixels (as a result of a 13,5 MHz scanning frequency).
Thus the pixel aspect ratio is 640/702 = 0,912
A 9px buffer is added on both sides to deal with horizontal deviation that might occur during the digitalization of an analog NTSC signal. In sum these borders to each side add up to 18px. So in the end we get a 720x480px frame.
The keychain camera produces an image where the complete buffer to the left and right contains valid image information.
Quote:
Originally Posted by scharfis_brain
This also means that 720x480 after aspect ratio correction are 657x480 pixels.
If there aren't any borders left and right (each about 9 pixels in width) you're lucky to have some additional image information which widenes the image.
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Got it! Thanks!
So if I don't cut the buffer area, since it indeed contains valid image information, I should actually configure the output to be 657x480px in pass 2, if I chose a 1:1 pixel aspect ratio for the output, right?