[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [ft-devel] gamma correction demo images

From: Alexei Podtelezhnikov
Subject: Re: [ft-devel] gamma correction demo images
Date: Fri, 20 Nov 2015 16:54:51 -0500

On Fri, Nov 20, 2015 at 2:46 PM, Nikolaus Waxweiler <address@hidden> wrote:
>> The filter is color-balanced, but not normalized. Values above 0x100
>> will have to be clamped and this non-linearity causes distortion and
>> adds to color fringing. Stem darkening is the better way to increase
>> contrast.
> So I tried to find two values that sum to 0x100:
>>>> def f(a,c):
> ...  return [a - c, a + c, 2 * a, a + c, a - c]

I did some experimentation with my crazy patterns. I firmly believe
now that simple box filter aka FT_LCD_FILTER_LIGHT is not just good
but in fact the best in reducing color fringes IFF used with correct
gamma. All color-balances filters with gamma eliminate color fringes
completely, but the box filter is obviously the least blurry of them
all. So I reached the same conclusion as this paper:
. Some day soon I will write a blog about the details of my

reply via email to

[Prev in Thread] Current Thread [Next in Thread]