Start here. These are the only colors you can get with full red,green,blue
and no red, no green and no blue. But you can get yellow magenta and cyan
or the printer's colors. However there are */255 255 255 colors available.
So maybe you will like 146 234 34 as your ordered triple. See if you can
make a dozen colors that you like or a dozen that are picked at random.
Until tomorrow..... I don't know all the answers to your questions but I
think they will be fun to tackle. I'm ready to go to bed!
Linda
require 'viewmat'
]P8=: 255* #:i.8
P8 viewmat (i.8);'Box of Crayons'
]Q8=:1 0 2{"1 P8
Q8 viewmat (i.8);'Colors Value 8'
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Peter B.
Kessler
Sent: Monday, March 31, 2014 9:34 PM
To: [email protected]
Subject: Re: [Jprogramming] Challenge 14; Colorful Creations
(Just to you, because I don't want to expose my ignorance any further than I
have to.)
I can see the value (pun intended) of having a grayscale palette that shades
smoothly from white to black. For example if I'm preparing a bar chart for
publication: I want to pick N different shadings that will be
distinguishable, and I want to arrange them such that the difference from
bar to bar is maximized. That is, five bars arranged 0.00, 0.50, 0.25,
1.00, 0.75 seems better than 0.00, 0.25. 0.50, 0.75, 1.00, on the theory
that 0.50 is clearly darker than its surrounding 0.00 and 0.25, 0.25 is
clearly lighter than 0.50 and 1.00, etc., so the bars will be
distinguishable. But I haven't actually made up such a chart.
As a user of color palettes, I want to say "I need N distinct colors, and
have those look nice whether they are in color or in grayscale". There
might be more to this than just "value". E.g., if I want 3 colors, can they
be red, yellow, and blue? The primary colors. If I want 6 colors, can I
get orange between the red and the yellow, green between the yellow and the
blue, and purple between the blue and the red? Or is rainbow order just an
accident of wavelength and not to be trusted? This seems more a matter of
art than of numerics.
In your GRB clock, I see what appears to be two areas of green: from 2 to
about 2:30, and then again from 4 to about 5:30. The RGB clock has only one
region of cyan. That seems confusing, but maybe I'm not meant to pick N
colors from the clocks by choosing even intervals around the clock.
Why does the GRB clock seem to have a smaller slice of cyan than the RGB
clock?
I'm always afraid these tests reveal more about my eyes and brain than about
the colors themselves. That would be a problem if my eyes are different
from everyone else's. yet another reason to rely on artists to pick colors
for me.
... peter
On 03/31/14 16:55, Linda Alvord wrote:
> Here's some information to ponder concerning grayscale images. "Value" is
a
> very important aspect of color. All the computer colors depend on Red,
Green
> and Blue light. However, Green is brighter than Red. So life would be
> simpler if we lived in a computer world which had number triples in GRB
> order. There are 5 different images created here. Because they are being
> timed, there are two of each image. Compare RGB and GRB. Compare Gray
> RGB and Gray GRB . The final image is a different strategy for obtainin
a
> grayscale image.
>
> require 'viewmat'
>
> at2=: 13 :'([:{:"1 *.) j./"1 y'
> RGB=: 255* #:i.8
> GRB=:1 0 2{"1 RGB
>
> we=: 13 :'<.0++/"1[0.3 0.59 0.11*"1 y'
> gray=: 13 :'3#"0 we y'
> ts=: 6!:2 , 7!:2@]
>
> ts 'RGB viewmat (D=.at2"0 /~ i:500);''RGB Clock'''
>
> ts 'GRB viewmat (D=.at2"0 /~ i:500);''GRB Clock'''
>
> ts '(gray RGB) viewmat (D=.at2"0 /~ i:500);''Gray RGB Clock'''
>
> ts '(gray GRB) viewmat (D=.at2"0 /~ i:500);''Better Gray GRB Clock Linda
> Alvord'''
>
> RM=: (# # +/ % #)"1
> ts 'RM(3#"0 i.255) viewmat (D=.at2"0 /~ i:500);''Better Gray Clock Raul
> Miller'''
>
>
> I am looking for the bes possible way to introduce the topic of color
images
> and their grayscale images. Also, in the next examples I would like to
show
> the value of "value" in analyzing numeric data. Please send any ideas
that
> might be useful.
>
>
> Linda
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Linda
Alvord
> Sent: Monday, March 31, 2014 12:35 AM
> To: [email protected]
> Subject: Re: [Jprogramming] Challenge 14; Colorful Creations
>
> require 'viewmat'
>
> at2=: 13 :'([:{:"1 *.) j./"1 y'
> ]P8=: 255* #:i.8
> ]Q8=:1 0 2{"1 P8
> ro=: 13 :'<.0.5+y'
> we=: 13 :'+/"1[0.3 0.59 0.11*"1 y'
> gray=: 13 :'3#"0 ro we y'
> ts=: 6!:2 , 7!:2@]
> ts '(gray P8) viewmat (D=:at2"0 /~ i:1000);''Better Gray Clock'''
>
> RM=: (# # +/ % #)"1
> grayRM=:RM P8
> ts 'RM(3#"0 i.255) viewmat D;''Better Gray Clock Raul Miller'''
>
> Q8=:1 0 2{"1 P8
> grayLA=: 13 :'1 0 2{"1 y'
> ts '(gray Q8) viewmat D;''Better Gray Clock Linda Alvord'''
>
> Both images look quite good. Is there some way to determine which is the
> better image or are they the same?
>
> Linda
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Raul Miller
> Sent: Sunday, March 30, 2014 4:17 PM
> To: Programming forum
> Subject: Re: [Jprogramming] Challenge 14; Colorful Creations
>
> Like this?
> (3#"0 i.255) viewmat D;'Grade from white to black, clockwise from
North'
>
> Thanks,
>
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