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  1. Member budwzr's Avatar
    Join Date: Apr 2007
    Location: City Of Angels
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    So my thinking now is that changes to contrast, color, brightness, sharpening, etc. are best done "before" upscaling low-def to hi-def. Is this in fact the correct procedure?

    I want to start collecting some of the free public domain stuff that's still somewhat interesting. I found some old gold mine maps online, so I want to enlarge some of the details. The maps are hand drawn, but quite detailed. But the resolution is 72dpi on a monitor.

    I would ideally like to print out sections on separate pages, like a regular atlas. Probably like to print at 300dpi to 8.5X11 pages, however many it takes.
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  2. I usually do most of the filtering before upscaling. For the most part, I only upscale animated material. Hand drawn maps would probably fit in that category.
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  3. Member budwzr's Avatar
    Join Date: Apr 2007
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    OK. Thanks. As a side note, is there any benefit to convert to grayscale?
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  4. Most black and white material has a color cast or noise in the chroma channels. I usually convert to pure greyscale. You get slightly better compression when the chroma channels are flat.
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  5. Member budwzr's Avatar
    Join Date: Apr 2007
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    Okey Dokey.
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  6. Originally Posted by budwzr View Post
    OK. Thanks. As a side note, is there any benefit to convert to grayscale?
    depends how this will be performed - if chroma plane will be clipped to 128 (YCbCr) then seem to be fine but if some fancy grayscale method is used then it can reintroduce chroma noise in luminance channel. I would recommend or "desaturate" or under Avisynth simple Limiter(0, 255, 128, 128) for YCbCr.
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  7. I usually use ColorYUV(cont_u=-256, cont_v=-256) because I'm usually using ColorYUV() anyway. GreyScale() works fine too.

    Beware, some other filters cause chroma problems. For example Stab() causes chroma to bounce up and down by a unit.
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