02-02-2021, 12:05 PM
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Is Spline36Resize, BilinearResize, or another tool best for converting 720x480 captures to 640x480?
Thanks,
Steve
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Someday, 12:01 PM
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02-02-2021, 12:25 PM
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Site Staff | Video
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Crop 720>704, then resize, if this is a VHS tape source.
Resize method really depends on the content. There's no single best method. Sometimes simple bicubic or bilinear appears best, while other times a spline or lanzcos looks better. You need to find some test areas, apply the filter, preview the aliasing noise and blur.
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The following users thank lordsmurf for this useful post:
archivarious (02-03-2021)
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02-02-2021, 01:32 PM
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Thanks!
I was planning to have "Crop(4,0,-8,-8).AddBorders(6,4,6,4)" before the resize. My crop is a bit smaller that what I've seen you use because the left side doesn't have much trash.
I recall reading that the black areas on the side of a 720 wide capture don't count toward the 4:3 aspect ratio and should be cut off before resizing--true? Is the switching noise at the bottom also not part of the 4:3 ratio and should be cropped off? I don't recall reading anything that mentioned the bottom trash was outside the 4:3 ratio space.
Should I go with the crop and border approach I was planning on using or should I just do an even crop from both sides to get 704 across with no top & bottom crop, resize to 640x480, then mask the bottom trash after the resize?
Thanks,
Steve
BTW: I will be outputting a 640x480 progressive video
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02-02-2021, 02:19 PM
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Quote:
Originally Posted by stevevid
I recall reading that the black areas on the side of a 720 wide capture don't count toward the 4:3 aspect ratio and should be cut off before resizing--true?
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Yes, that's the D1 standard, ITU-R 601 (orig. CCIR-601), a.k.a Rec. 601 by SMPTE engineering committees.
Quote:
Originally Posted by stevevid
Is the switching noise at the bottom also not part of the 4:3 ratio and should be cropped off? I don't recall reading anything that mentioned the bottom trash was outside the 4:3 ratio space.
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No, Unless your capture device captures at 486 lines then you get the luxury of cropping off those 6 lines from anywhere you want, top, bottom or a combination of top and bottom.
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02-02-2021, 03:55 PM
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The rule of thumb : if you want to upscale you want sharp so you should use spline36 (or 64)
for a downscale you might want to smooth details thus: bilinear.
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The following users thank themaster1 for this useful post:
archivarious (02-03-2021),
lollo2 (02-03-2021)
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