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Re: [css] Proposal: making Shorthand Hex Colors even shorter (16 grayscale shades)

From: Marat Tanalin <mtanalin@yandex.ru>
Date: Fri, 09 Sep 2011 20:10:08 +0400
To: Alan Gresley <alan@css-class.com>
Cc: Tab Atkins Jr. <jackalmage@gmail.com>,www-style@w3.org
Message-Id: <499711315584608@web66.yandex.ru>
There is no need to tell us about abstract binary representation of data in general since we are all already know this. Saying "nature" as for RGB in CSS, I mean that existing widely-used 24-bit RGB color table includes 256 values for each RGB channel (8 bit per RGB-channel), and that's why hex representation can be used to specify colors.

Unlike color, opacity is _multiplier_ and is not and should not be limited to 256 gradations. Currently, opacity in standard CSS is specified as decimal number (e.g., in "rgba()" function, in "opacity" property), and decisions as for new CSS-spec features should be consistent with existing ones.


07.09.2011, 07:28, "Alan Gresley" <alan@css-class.com>:
> On 7/09/2011 5:26 AM, Marat Tanalin wrote:
>
>>  2. As for alpha opacity. The only reason why RGB components can be
>>  represented as hex is that each RGB component has exactly 256
>>  possible values _by nature_.
>
> This is an statement that has no foundation. There is 256 possible
> values since all values must be transmitted as binary code which has
> only two value (either 0 or 1). Computing has expanded this in multiples
> like so:
>
>    2, 4, 8, 16, 32, 64, 128, 256, 512, 1024.
>
> A calculator set to decimals (dec), will change the value 'FF' to '255'
> when hexadecimals (hex) is selected.
>
> RGB color space can not be said to be *by nature*. Please read about RGB
> color space [1].
>
>    | RGB is a convenient color model for computer graphics
>    | because the human visual system works in a way that
>    | is similar — though not quite identical — to an RGB
>    | color space.
>
> As I know from personal experimentation, color and human perception of
> it is far more mysterious than what is known in the mainstream science,
> but is is far from the scope of this thread.
>
> 1. http://en.wikipedia.org/wiki/RGB_color_space
>
> --
> Alan Gresley
> http://css-3d.org/
> http://css-class.com/
Received on Friday, 9 September 2011 16:10:48 GMT

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