Re: RGB color: enhancement request

On 02/08/07, Henry G Belot wrote:

> Theo:
>
>>; ...So they bring us not all the colors in the world as I thought (but
>;> still a bit better than we now see on our screens, and really better
>> than my own 18 bit screen).
>>
>
> Of course, a lot of this is impractical. The number of colors we can
> distinguish under laboratory conditions using highly specialized tests
> and the number we can actually distinguish in real life around us is
> quite different.

It depends on the situation. People often notice banding in light blue
sky areas on 24-bit images.

Or try making a smoothly graded background that really looks smooth.

The problem here tends to be that although there may be 16 million
colors altogether, the number used in a gradient (for instance in sky)
is a tiny fraction of that - maybe only 20 or 30.

8 bit primaries are not always enough.

> I no longer remember the practical limits, but I
> believe it's in the low 5-digit area. The quest to get natural color
> in the various forms of photography is largely one of adjusting the
> biases of various ways of recording color. But, at the same time,
> people tend to like some of these biases and that's part of the "art."
> In traditional photography, some people preferred Ektachrome and
> others Kodachrome. I took to using Japanese brands when I was
> vacationing in Japan because they had a way of catching the colors
> people used in painting homes and businesses, particularly the greens.
>
> Digital cameras of all types have their own biases as you'll see in
> the detailed test reports on the Internet. To what extent exploding
> the gamut or any other measurable dimension of color would eliminate
> that, I've no idea. But color matching between media is a toughie.
> Consider, for example, that many motion pictures are now being
> archived in digital formats, and those digital prints are likely to be
> the standard reference for all future uses. Consider that in making
> those archive copies, there's a human being making decisions about
> what the colors should be and making that decision based on what (s)he
> sees on a monitor with its own peculiarities. (Hopefully also based on
> a reference print of the film from an original negative which hasn't
> deteriorated significantly.)

I was just reading a blog by a guy who worked for Disney when the
classic films were being released on video. The bear in "Jungle Book" is
grey in the original artwork, but the person doing the video conversion
adjusted the color to make the bear brown, ("Everyone knows"; bears are
brown, tree trunks are brown, and alligators are green.)

Result was wrong color balance in the backgrounds.

>;
> But then those matters have never been "perfect." Even in the
> traditional film environment, there's a laboratory and people called
> "color timers" making similar decisions.
>
> HB
Indeed there are, and the photographer will go through the test print
making notes for the lab where the color balance is wrong.

One point is that if the image is a photographic style image, the eye
will adjust over quite a wide range of color balance, just as it does to
lighting in real life. But if you are printing diagrams, lettering,
logos etc, the eye does not adjust in the same way. It is very obvious
when blue lettering prints purple.

Regards
--
Don Cox
doncox%40enterprise.net">doncoxenterprise.net

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Don Cox wrote:
> On 02/08/07, Henry G Belot wrote:
>
>>; Theo:
>>
>>> ...So they bring us not all the colors in the world as I thought (but
>;>> still a bit better than we now see on our screens, and really better
>>> than my own 18 bit screen).
>>>
>>; Of course, a lot of this is impractical. The number of colors we can
>> distinguish under laboratory conditions using highly specialized tests
>> and the number we can actually distinguish in real life around us is
>> quite different.
>
> It depends on the situation. People often notice banding in light blue
>; sky areas on 24-bit images.
>
> Or try making a smoothly graded background that really looks smooth.
>
> The problem here tends to be that although there may be 16 million
> colors altogether, the number used in a gradient (for instance in sky)
>; is a tiny fraction of that - maybe only 20 or 30.

I think that will depend upon the resolution and/or the screen frequency
at which you print. Having palette greater than 24-bit shouldn't help that.

> 8 bit primaries are not always enough.
>
>>; I no longer remember the practical limits, but I
>> believe it's in the low 5-digit area. The quest to get natural color
>> in the various forms of photography is largely one of adjusting the
>> biases of various ways of recording color. But, at the same time,
>> people tend to like some of these biases and that's part of the "art."
>> In traditional photography, some people preferred Ektachrome and
>> others Kodachrome. I took to using Japanese brands when I was
>> vacationing in Japan because they had a way of catching the colors
>> people used in painting homes and businesses, particularly the greens.
>>
>> Digital cameras of all types have their own biases as you'll see in
>> the detailed test reports on the Internet. To what extent exploding
>> the gamut or any other measurable dimension of color would eliminate
>> that, I've no idea. But color matching between media is a toughie.
>> Consider, for example, that many motion pictures are now being
>> archived in digital formats, and those digital prints are likely to be
>> the standard reference for all future uses. Consider that in making
>> those archive copies, there's a human being making decisions about
>> what the colors should be and making that decision based on what (s)he
>> sees on a monitor with its own peculiarities. (Hopefully also based on
>> a reference print of the film from an original negative which hasn't
>> deteriorated significantly.)
>
> I was just reading a blog by a guy who worked for Disney when the
> classic films were being released on video. The bear in "Jungle Book" is
> grey in the original artwork, but the person doing the video conversion
> adjusted the color to make the bear brown, ("Everyone knows"; bears are
> brown, tree trunks are brown, and alligators are green.)
>
> Result was wrong color balance in the backgrounds.

Obviously, when you adjust the color for the whole picture.

>>; But then those matters have never been "perfect." Even in the
>>; traditional film environment, there's a laboratory and people called
>>; "color timers" making similar decisions.
>>
>> HB
> Indeed there are, and the photographer will go through the test print
> making notes for the lab where the color balance is wrong.
>
> One point is that if the image is a photographic style image, the eye
> will adjust over quite a wide range of color balance, just as it does to
> lighting in real life. But if you are printing diagrams, lettering,
> logos etc, the eye does not adjust in the same way. It is very obvious
> when blue lettering prints purple.
>
> Regards

--
DAVID L. STEVENS -- TEAM AMIGA --Chapter Chat Publisher
Windows XP user (:^(> on Acer Aspire 9810 2.16 GHz Notebook
2 GB RAM; 2 120-GB Hard Drives; CanoScan LIDE 20
Canon i860 & Brother HL-5050 PageStream v5.0.2.10Pro
<http://davestevens.home.insightbb.com>;

Dilbert's Words of Wisdom: I'd explain it to you, but your brain would
explode.

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