Color depth - Wikipedia, the free encyclopedia
Roger Bagula
Does anyone know how to access thousand and millions of
colors in Mathematica?
Respectfully, Roger L. Bagula
11759 Waterhill Road, Lakeside,Ca 92040-2905,tel: 619-5610814 :
http://www.google.com/profiles/Roger.Bagula
alternative email: roger....@gmail.com
dh
Roger Bagula wrote:
> http://en.wikipedia.org/wiki/Color_depth
>
> colors in Mathematica?
>
> Respectfully, Roger L. Bagula
> http://www.google.com/profiles/Roger.Bagula
> alternative email: roger....@gmail.com
>
>
>
Hi Roger,
as Mathematica can calculate with real double precision numbers, the
number of colors is presumably restricted by your graphics card and
monitor and not by Mathematica.
See e.g. RGBColor.
Daniel
Bill Rowe
>http://en.wikipedia.org/wiki/Color_depth
>Does anyone know how to access thousand and millions of colors in
>Mathematica?
In Mathematica, color (RGBColor) is determined by a set of three
to four real values from 0 to 1. The fourth value is the alpha
channel (opacity) and defaults to 1 when only r,g,b values are given.
=46or millions of colors, each channel is normally represented as
an 8-bit value. So, here is an example of converting a
Mathematica RGBColor to 8-bits per channel
In[4]:= Round[255 List @@ ColorData[1][1]]
Out[4]= {63,61,153}
This particular color is the default color used by Plot and
ListPlot when plotting a single curve or data set.
Sjoerd C. de Vries
who has been around for a while I cannot imagine that you haven't been
working with colors before.
Manipulate[
Graphics[{RGBColor[r, g, b], Disk[]}], {r, 0, 1, 1/256}, {g, 0, 1,
1/256}, {b, 0, 1, 1/256}]
Cheers -- Sjoerd
On Nov 22, 1:16 pm, Roger Bagula <rlbag...@sbcglobal.net> wrote:
> http://en.wikipedia.org/wiki/Color_depth
>
> Does anyone know how to access thousand and millions of
> colors in Mathematica?
>
> Respectfully, Roger L. Bagula
> 11759 Waterhill Road, Lakeside,Ca 92040-2905,tel: 619-5610814 :http://www=
.google.com/profiles/Roger.Bagula
> alternative email: roger.bag...@gmail.com
DrMajorBob
think, yet I (still) have no answer to Roger's post.
There's nothing in your Manipulate (or in Help for RGBColor) to indicate
the number of colors available.
Just because you've stepped your controls in units of 1/256 doesn't mean
the unit matters to RGBColor.
Bobby
On Mon, 23 Nov 2009 05:48:46 -0600, Sjoerd C. de Vries
<sjoerd.c...@gmail.com> wrote:
> This looks like a troll or I am missing something here? For someone
> who has been around for a while I cannot imagine that you haven't been
> working with colors before.
>
> Manipulate[
> Graphics[{RGBColor[r, g, b], Disk[]}], {r, 0, 1, 1/256}, {g, 0, 1,
> 1/256}, {b, 0, 1, 1/256}]
>
> Cheers -- Sjoerd
>
> On Nov 22, 1:16 pm, Roger Bagula <rlbag...@sbcglobal.net> wrote:
>> http://en.wikipedia.org/wiki/Color_depth
>>
>> Does anyone know how to access thousand and millions of
>> colors in Mathematica?
>>
>> Respectfully, Roger L. Bagula
>> 11759 Waterhill Road, Lakeside,Ca 92040-2905,tel: 619-5610814
>> :http://www=
> .google.com/profiles/Roger.Bagula
>> alternative email: roger.bag...@gmail.com
>
>
Patrick Scheibe
assume the following graphic in Mathematica
With[{n = 4^2},
ArrayFlatten[
Partition[
Table[{x, y, z}, {z, 0, 1, 1/(n - 1)}, {y, 0, 1, 1/(n - 1)}, {x,
0, 1, 1/(n - 1)}], Sqrt[n]]]] //
ArrayPlot[#, ColorFunction -> RGBColor] &
when you check the values for the colors in this image you'll see that
every pixel has different rgb-values. This means if you put n=16^2 you
would have 256x256x256 colors in the image which is exactly what
"millions of colors" is supposed to be.
Since the table creates rational expressions for the {r,g,b} colors you
could easily (with the restriction that an image of that size would take
too long to render in Mathematica) create more colors by setting higher
values to n.
But what does this mean? Are there really that many visible colors on
your screen? What happens if you export the image?
This depends many things, e.g. on your os-settings.
So if you really want to know more, you have to tell more about what you
try to achieve and which things are not working for you.
Cheers
Patrick
On Sun, 2009-11-22 at 06:11 -0500, Roger Bagula wrote:
> http://en.wikipedia.org/wiki/Color_depth
>
> Does anyone know how to access thousand and millions of
> colors in Mathematica?
>
> Respectfully, Roger L. Bagula
> 11759 Waterhill Road, Lakeside,Ca 92040-2905,tel: 619-5610814 :
> http://www.google.com/profiles/Roger.Bagula
> alternative email: roger....@gmail.com
>
>
>
DrMajorBob
And you're right, my apologies... I stopped reading too soon, or stopped
paying attention.
(Sometimes it's "Short Attention-Span Theater", here.)
Bobby
On Wed, 25 Nov 2009 17:42:21 -0600, Patrick Scheibe
<psch...@trm.uni-leipzig.de> wrote:
> Hi,
>
> why do you quote just this sentence and not the one where I said that
> it's not clear what exactly this means?
> But to make it clear: on my system
>
> img = With[{n = 16^2},
> ArrayFlatten[
> Partition[
> Table[{x, y, z}, {z, 0, 1, 1/(n - 1)}, {y, 0, 1, 1/(n - 1)}, {x,
> 0, 1, 1/(n - 1)}], Sqrt[n]]]] // Image[#, "Real"] &;
> Export["~/tmp/24bit.bmp", img, "ColorDepth" -> 24]
>
> results in an image which really has 256^3 different colors and *no*, I
> could not see the difference between adjacent pixels since my eyes are
> too bad. But Gimp told me that every pixel is different and
>
> img2 = Import["~/tmp/24bit.bmp"];
> Union@Flatten[img2[[1]], 1] // Dimensions
>
> {16777216, 3}
>
> looks promising too.
> I hope this was what Roger wanted to know.
>
> Cheers
> Patrick
>
>
> On Wed, 2009-11-25 at 16:53 -0600, DrMajorBob wrote:
>> > every pixel has different rgb-values. This means if you put n=16^2 you
>> > would have 256x256x256 colors...
>>
>> No... it means you'd have RGBColor with 256x256x256 distinct parameter
>> triplets. That doesn't prove they're all distinct, implemented COLORS.
>>
>> We could set n=1024^2 just as easily, but is there an implemented color
>> model (in Mathematica) with the required depth?
>>
>> Bobby
DrMajorBob
Patrick Scheibe
why do you quote just this sentence and not the one where I said that
it's not clear what exactly this means?
But to make it clear: on my system
img = With[{n = 16^2},
ArrayFlatten[
Partition[
Table[{x, y, z}, {z, 0, 1, 1/(n - 1)}, {y, 0, 1, 1/(n - 1)}, {x,
0, 1, 1/(n - 1)}], Sqrt[n]]]] // Image[#, "Real"] &;
Export["~/tmp/24bit.bmp", img, "ColorDepth" -> 24]
results in an image which really has 256^3 different colors and *no*, I
could not see the difference between adjacent pixels since my eyes are
too bad. But Gimp told me that every pixel is different and
img2 = Import["~/tmp/24bit.bmp"];
Union@Flatten[img2[[1]], 1] // Dimensions
{16777216, 3}
looks promising too.
I hope this was what Roger wanted to know.
Cheers
Patrick
On Wed, 2009-11-25 at 16:53 -0600, DrMajorBob wrote: