POV-Ray : Newsgroups : povray.binaries.images : colors from images Server Time: 20 Jun 2019 07:05:31 GMT
  colors from images (Message 11 to 16 of 16)  
<<< Previous 10 Messages Goto Initial 10 Messages
From: Jörg "Yadgar" Bleimann
Subject: Re: colors from images
Date: 13 May 2019 23:57:49
Message: <5cda047d$1@news.povray.org>
Hi(gh)!

On 13.05.19 20:34, Norbert Kern wrote:

> Sounds nice - can it be implemented in povray? ;-)

Theoretically, yes - but it wouldn't be such a good idea, as it would be 
excruciatingly slooooooow!

> Orange-Teal look is a color-grading effect to emphasize blue colors in shadows
> and orange colors at highlights. It can enhance an mediocre image a lot, if
> applied carefully.
> Here is a typical example -
>
http://server.felixhuesken.de/lgg_orangeteal/orange-teal_blockbuster_look_jurassicworld_color_grading.png

Hmmm... as I assumed, 180 degrees apart on the hue circle!

See you in Khyberspace!

Yadgar

Now playing: Synthesist (Harald Großkopf)


Post a reply to this message

From: Paolo Gibellini
Subject: Re: colors from images
Date: 15 May 2019 09:24:18
Message: <5cdbdac2$1@news.povray.org>
Norbert Kern wrote on 13/05/2019 18:59:
> Many thanks - I wasn't conscious about the second link - very interesting.
> First I used a cubic space too, but hsl space is more convincing in the end.
> Personally I use it as a tool to detect color errors in my images. Here is an
> example with the last version of an old image of mine...
> 
> Because I render 16 bit png images, there aren't many defects as in 8 bit jpegs.
> But what you mentioned, is something different. I included the web origins in
> the source (p.b.s-f).
> Perhaps the JW3 person didn't process the poster as heavily as the other one -
> DP2.
> 
> "Orange-Teal" is one of the most common color-grading effects used at
> movie-making or by professional photographers.
> There are many variants like enhencing blue colors in shadows and orange ones in
> highlights and a bit in midtones.
> 
> I made a pov version, which gave ugly results and I cannot even find the file...
> 
> 
> Norbert
> 

The result looks good.
Paolo


Post a reply to this message

From: jr
Subject: Re: colors from images
Date: 16 May 2019 22:20:01
Message: <web.5cdde14ab81912f8a2aab1e70@news.povray.org>
hi,

"Norbert Kern" <nor### [at] t-onlinede> wrote:
> > very nice.  ...  does the code not work with "black and white"?
> Hmmh - I don't know, how a perfect black and white is depicted in hsl space.
> Perhaps it is not a cylinder, but a double cone with black and white as single
> points at top and bottom - but I don't think this is the case.
>
> If you used extremely large images as input, you get very small spheres and if
> you really have mostly black colors, you get an almost blank result. Perhaps it
> helps, if you increase the sphere radius.

thanks for that.  image size is not a factor, they're all (much) smaller than
the images you used.  I'm guessing that the image is simply too ill-lit.  fwiw,
I've been converting some music related images, album covers and such, and
include one "favourite".


regards, jr.


Post a reply to this message


Attachments:
Download 'inexpressible432hz.png' (582 KB)

Preview of image 'inexpressible432hz.png'
inexpressible432hz.png


 

From: Bald Eagle
Subject: Re: colors from images
Date: 17 May 2019 10:35:00
Message: <web.5cde8da1b81912f84eec112d0@news.povray.org>
Interesting -
There are those very noticeable "absent lines" radiating from the center, and
some fainter annular spaces going around.

Makes me wonder how you'd take those missing colors and reconstruct the image
with only those.

Or something like that.  ;)


Post a reply to this message

From: jr
Subject: Re: colors from images
Date: 17 May 2019 23:20:00
Message: <web.5cdf40d0b81912f8a2aab1e70@news.povray.org>
hi,

"Bald Eagle" <cre### [at] netscapenet> wrote:
> Interesting -
> There are those very noticeable "absent lines" radiating from the center, and
> some fainter annular spaces going around.

not always though.  no absent lines apparent in the image Norbert posted on the
13th.

I'm fascinated by how the resulting images always (it seems.  after ~20 tests)
appear different from the expectation.


> Makes me wonder how you'd take those missing colors and reconstruct the image
> with only those.
>
> Or something like that.  ;)

:-)


regards, jr.


Post a reply to this message

From: Norbert Kern
Subject: Re: colors from images
Date: 18 May 2019 00:15:00
Message: <web.5cdf4e12b81912f83c1c78400@news.povray.org>
"jr" <cre### [at] gmailcom> wrote:
> hi,
>
> "Bald Eagle" <cre### [at] netscapenet> wrote:
> > Interesting -
> > There are those very noticeable "absent lines" radiating from the center, and
> > some fainter annular spaces going around.
>
> not always though.  no absent lines apparent in the image Norbert posted on the
> 13th.
>
> I'm fascinated by how the resulting images always (it seems.  after ~20 tests)
> appear different from the expectation.
>
>
> > Makes me wonder how you'd take those missing colors and reconstruct the image
> > with only those.
> >
> > Or something like that.  ;)
>
> :-)
>
>
> regards, jr.



Me too,

it's a "negative" tool IMHO.
You can easily detect lacking colors.

Norbert


Post a reply to this message

<<< Previous 10 Messages Goto Initial 10 Messages

Copyright 2003-2008 Persistence of Vision Raytracer Pty. Ltd.