Re: 14->16
Re: 14->16
- Subject: Re: 14->16
- From: Robin Myers <email@hidden>
- Date: Thu, 01 Nov 2001 07:32:41 -0800
- Organization: Robin Myers Imaging
Anthony Sanna wrote:
>
Most good quality scanners that I know of scan in 14-bits (do any capture
>
16-bits?). Since this information gets passed on to Photoshop as 8 or
>
16-bit information, my question is how this 14-bit information (16,384
>
discrete shades/channel) is translated into 16-bit?
.
.
.
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But when taking the 16,384 levels of 14-bit capture information and
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fitting it into Photoshop's 16-bit bucket, do you end up with a bucket
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filled with 65,536 shades of extrapolated information, or a 16-bit bucket
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that's only a quarter full?
Most software packages scale the 14-bit information into the 16-bit range by
multiplying each value by 4. However, as Bruce Lindbloom has previously
noted, even though the information is in a 16-bit range Photoshop will force
the lowest bit to 0, so even if you have full 16-bit data there will only be
15-bits of information. Confusing?! Perhaps one of the Adobe lurkers can
explain why they need to throw away one bit of information?
Robin Myers