Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.programming > #5377

Re: darkening colour

From Bartc <bc@freeuk.com>
Newsgroups comp.programming
Subject Re: darkening colour
Date 2015-04-06 11:21 +0100
Organization A noiseless patient Spider
Message-ID <mftmmf$v1m$1@dont-email.me> (permalink)
References <7b8397af-4857-4de4-828f-a1ebe1b83ae1@googlegroups.com> <ti6kvne8w9v.11mahuf4ewkii$.dlg@40tude.net>

Show all headers | View raw

On 06/04/2015 09:52, Dmitry A. Kazakov wrote:
> On Mon, 6 Apr 2015 01:12:42 -0700 (PDT), fir wrote:
>
>> s really simple metgod of multiplying
>> each r,g,b component by some scalar v
>> like
>>
>> r*=f;
>> g*=f;
>> b*=f;
>>
>> the appropriate way of darkening or brightening
>> a color? (/whole image)
>
> No, it isn't, because RGB stimuli are not proportional to the luminance.
>
>> or there is something better maybe?
>
> Convert RGB to the L*a*b color space change luminance, convert back.  > A less computation intensive model...

Is that what happens when I adjust the brightness control on my HD TV? I 
wonder they use to do these computations at 50M pixels per second.

-- 
Bartc

Back to comp.programming | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

darkening colour fir <profesor.fir@gmail.com> - 2015-04-06 01:12 -0700
  Re: darkening colour "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-04-06 10:52 +0200
    Re: darkening colour Bartc <bc@freeuk.com> - 2015-04-06 11:21 +0100
      Re: darkening colour "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-04-06 12:44 +0200
        Re: darkening colour Bartc <bc@freeuk.com> - 2015-04-06 12:54 +0100
          Re: darkening colour "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-04-06 14:27 +0200
          Re: darkening colour fir <profesor.fir@gmail.com> - 2015-04-06 05:51 -0700
    Re: darkening colour fir <profesor.fir@gmail.com> - 2015-04-06 04:38 -0700
      Re: darkening colour "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-04-06 14:52 +0200
        Re: darkening colour fir <profesor.fir@gmail.com> - 2015-04-06 06:25 -0700
          Re: darkening colour "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-04-06 17:02 +0200
            Re: darkening colour fir <profesor.fir@gmail.com> - 2015-04-06 09:36 -0700
              Re: darkening colour "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-04-07 10:52 +0200
                Re: darkening colour fir <profesor.fir@gmail.com> - 2015-04-07 02:10 -0700
                Re: darkening colour "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-04-07 11:30 +0200
                Re: darkening colour fir <profesor.fir@gmail.com> - 2015-04-07 03:24 -0700
                Re: darkening colour "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2015-04-07 13:00 +0200
      Re: darkening colour Bartc <bc@freeuk.com> - 2015-04-06 14:17 +0100
        Re: darkening colour fir <profesor.fir@gmail.com> - 2015-04-06 06:27 -0700
          Re: darkening colour Bartc <bc@freeuk.com> - 2015-04-06 14:39 +0100
            Re: darkening colour fir <profesor.fir@gmail.com> - 2015-04-06 06:48 -0700
              Re: darkening colour Bartc <bc@freeuk.com> - 2015-04-06 16:02 +0100
                Re: darkening colour fir <profesor.fir@gmail.com> - 2015-04-06 09:44 -0700
                Re: darkening colour Bartc <bc@freeuk.com> - 2015-04-06 21:05 +0100
                Re: darkening colour fir <profesor.fir@gmail.com> - 2015-04-07 00:51 -0700
                Re: darkening colour fir <profesor.fir@gmail.com> - 2015-04-07 01:12 -0700

csiph-web