Re: MMX speedup for Floyd Steinberg error diffusion

rep_movsd  <spamtrap@[EMAIL PROTECTED]
> writes:
>> Phil, you're absolutely right, and that's why "doing it right" is even
>> harder than you're showing here:
>
> There is this color quantizer/ditherer program called scolorq which
> uses some highly advanced techniques with floating point precision. I
> tried that out and it took an astoni****ng amount of time for a single
> frame ( I let it run for 3 minutes before giving up in disgust ).
> Turns out it has 5 deep nested loops. Some site online shows pretty
> impressive results for reduction to 16 color images. Perhaps the
> algorithm doesnt scale to 256 colors.
>
> Ill try out your approach with palette lists and see how it goes...
>
>> The color space should probably be gamma-adjusted, and the error terms
>> should be calculated in a linear space, otherwise the error diffusion
>> terms won't add up properly.
>>
>> OTOH, at the time we start to worry about stuff like this, 8-bit GIF
>> images with palettized colors shouldn't be considered for the job,
>> right? :-)
>
> It seems to be a tribute to the human eye that even when the image
> information is reduced by a factor of 2^16, the artifacts of
> palettization and dithering are hardly noticed.

However, the information is not reduced by a factor of 2^16,
number of choices != quantity of information.

Phil
-- 
Dear aunt, let's set so double the killer delete select all.
-- Microsoft voice recognition live demonstration