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10/22/2004 11:12:32 PM · #1 |
I know that when you are up-sizing images for whatever reason, you need to use several gradual passes to get the best quality in the final result.
But does this also hold true when you are down-sizing? Off the top of head I would think "yes" but I'm not sure. Should I spend the time to use lots of gradual passes or just do it in 1 or 2 passes?
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10/22/2004 11:36:13 PM · #2 |
I can't explain the rationale, but pretty much everybody downsamples in one pass.
With the new algorithms in PS CS, you can upsample in one pass too. |
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10/22/2004 11:40:08 PM · #3 |
In Photoshop CS Downsample with Bicubic Sharper and Upsample with Bicubic Smoother.
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10/23/2004 12:05:46 AM · #4 |
Good info, I didn't know that about CS. Is this (1 pass) the same for PS 7.0 or is it a new feature/enhancement in CS? I may have to pry open my wallet and upgrade to CS? :D
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10/23/2004 12:28:06 AM · #5 |
Originally posted by ChrisW123:
Good info, I didn't know that about CS. Is this (1 pass) the same for PS 7.0 or is it a new feature/enhancement in CS? I may have to pry open my wallet and upgrade to CS? :D |
Just CS. They enhanced the interpolation routines to remove the need for multi-pass resizing. Ends up being a lot faster as a result.
The biggest advantage to me of CS is the all 16 bit workflow (or almost all) that is available now. There are a load of other photography specific bells and whistles though, good RAW support, photo filter effects and the like.
Message edited by author 2004-10-23 00:29:20. |
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10/23/2004 12:32:16 AM · #6 |
The main difference would be in one-step upsampling. You don't need to spend the money for the very slight improvement in downsampling. (Except for the stuff Gordon mentioned!)
I'd strongly suggest you take small sections of two images -- one smooth and one with lots of detail -- and try both upsampling and downsampling in both increments and single-step. The only really meaningful comparison is which way you think your images come out better; almost everything else is opinions of people you don't know, evaluating images you haven't seen.
Message edited by author 2004-10-23 00:33:13. |
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10/23/2004 12:42:14 AM · #7 |
Originally posted by GeneralE:
The main difference would be in one-step upsampling. You don't need to spend the money for the very slight improvement in downsampling. (Except for the stuff Gordon mentioned!)
I'd strongly suggest you take small sections of two images -- one smooth and one with lots of detail -- and try both upsampling and downsampling in both increments and single-step. The only really meaningful comparison is which way you think your images come out better; almost everything else is opinions of people you don't know, evaluating images you haven't seen. |
I'd even suggest taking it one step further - after you've scaled them in the various ways, print them out and compare those results.
100% views on a screen are all very well, but if you are resizing for printing, it is how the print looks that matters, not the pixels.
Another thing to realise is that the current 'state of the art' best upsampling approach in Photoshop is in the Adobe RAW convertor. This is claimed to be better than even bicubic smoother or step interpolation, but has a more limited range of final output sizes.
Message edited by author 2004-10-23 00:53:45. |
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10/23/2004 01:13:43 AM · #8 |
Originally posted by Gordon:
I'd even suggest taking it one step further - after you've scaled them in the various ways, print them out and compare those results.
100% views on a screen are all very well, but if you are resizing for printing, it is how the print looks that matters, not the pixels. |
Great point! My 14-cent 4x6 prints from Costco look way better than anything on my monitor ... : ) |
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