POV-Ray : Newsgroups : povray.general : Image_map question : Re: Image_map question Server Time
1 Mar 2024 20:05:05 EST (-0500)
  Re: Image_map question  
From: David Kraics
Date: 25 Nov 2023 14:10:00
Message: <web.6562463c4becaf926633439fa57e0@news.povray.org>
Alain Martel <kua### [at] videotronca> wrote:

> > I keep running into an issue. I image_map a jpeg onto a box. In the image
> > created, the jpeg's lines are greatly faded. Darkening the jpeg doesn't improve
> > this. Am I missing something? The one I am currently using is;
> >
> >
> >   box{<-.5,0,0>,<.5,3.097,.45>
> >
> >    pigment{
> >      image_map{jpeg"tower.jpg"}
> >      scale<1,3.097,1>
> >      translate<-.5,0,0>
> >      }
> >   }
> >
> > The scale is to match the box it is on.
> > The original jpeg is a blueprint with firm solid black lines. The image is
> > greatly faded. Am I missing a function or someting?
> >
> Some things that you may try :
> Adding a gamma value to the pigment. Try values more and less than 1.
> Adding a layered pigment with a transmit value larger than 1 above that
> pigment.
>
> box{<-.5,0,0>,<.5,3.097,.45>
>
>    pigment{
>      image_map{jpeg"tower.jpg"}
>      scale<1,3.097,1>
>      translate<-.5,0,0>
>      }
> // Add this
>    pigment{rgbt<0.5,0.5,0.5,1.5>}
>   }
>
> A transmit of more than 1 increase the contrast, and the 0.5 make areas
> with a value less than 0.5 darker and the area with a value larger than
> 0.5 brighter. There are a few sample scenes that illustrate this.
>
> Some other things to look for :
> If the black is not pure black, an ambient value that is set to large in
> a #default statement can be an issue.
> Also, to much light illuminating the box tend to wash out things.
> Make sure that the black is really black : RGB <0,0,0>


Added that line and the prim turned invisible. Tried autocontrast on my paint
software. I attached the file. I am using this image as a blueprint so it won't
be in the final picture, so I am just dealing with squinting for now.


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Attachments:
Download 'tower.jpg' (18 KB)

Preview of image 'tower.jpg'
tower.jpg


 

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