[sane-devel] brightness/contrast/gamma LUT ideas?

[m. allan noah]

>> i need suggestions or pointers to code that i could use. what things i can
>> find are far over my head, but i have a simple brightness adjustment that
>> shifts the linear slope of the in-out function up or down, and a crude
>> contrast setting that changes the slope of the function around the center
>> of the table. i think both of these methods are likely too simplistic.
>>
>> anyone?
>>
> you might want to have a look @ plustek-usbmap.c, where the brightness &
> contrast adjustment isdone for the plustek backend. It's quite simple
> and works okay (tm) ;)
>

that is similar to what i have written, except your contrast ramp is 
limited to slope 2, and the ramp begins at 0, rather than centering in the 
visible range.

this means an increase in contrast only affects the dark colors, while 
all light colors will get clamped to white? i bet if you set contrast to 
0, you get solid black, when you should get solid middle gray?

allan

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