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A comment on Gamma error in picture scaling. Parent comment

Re:Gamma error in picture scaling by mark-r on Friday January 04, 2019 @07:15PM (#18828999)
Oh, the lookup tables are cached just fine. It's just that they crowd out something else.
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Re:Gamma error in picture scaling by burfog on Saturday January 05, 2019 @01:52AM (#18830379)
That "something else" is already crowded out by running through a multi-megabyte image.

At least the instruction cache is barely affected, which would not be the case for a math library function.

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Re:Gamma error in picture scaling by AstralStorm on Tuesday January 08, 2019 @03:09AM (#18854085)
You're not running a multi MB image but a small block thereof. Not that 5-6KiB LUT matters, but the extra conditional multiply ops or power or logarithm function evaluations do. Latter are need a few MACs for a good approximation (at least 12 bit precise, preferably 16 bit - like 5th order polynomial), former have masks, worse for SIMD.
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