POV-Ray : Newsgroups : povray.general : A problem regarding the size of the rentered image Server Time
27 Nov 2024 03:50:58 EST (-0500)
  A problem regarding the size of the rentered image (Message 1 to 4 of 4)  
From: trexgr
Subject: A problem regarding the size of the rentered image
Date: 17 Jun 2009 19:45:00
Message: <web.4a397e95c07ea764a3551df40@news.povray.org>
Hello all.

I am completely new to rentering with pov-ray, and I have a question that is
bugging me for a while today. After creating an image in VMD, I used the
pov-ray rentering option, produced a .pov file, then used the pov-ray program
in Windows, and produced a nice BMP file. I cannot, however have access to the
size of the output file, and the resolution, i.e how many pixels per inch (DPI,
or PPI) my output picture should be. I tried to check the Help, and I can change
the width and the height of the image, in pixels (the program calls THIS as
resolution, the output of 1024x780 pixels for example).

This however is only a part of the solution. How can I have absolute control of
the size of the image (its a simple 2D image by the way, no animation) and its
resolution ? For example, how can I specify that the output picture should be
EXACTLY 5.43 inch x 3.24 inch, with 300 DPI resolution? Also, where and how do
I change the output type, and instead of BMP get either TGA or TIFF ?

Thanks in advance
t.


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From: clipka
Subject: Re: A problem regarding the size of the rentered image
Date: 17 Jun 2009 21:15:01
Message: <web.4a3993f6dd1514c45339cfa0@news.povray.org>
"trexgr" <vic### [at] yahoocom> wrote:
> This however is only a part of the solution. How can I have absolute control of
> the size of the image (its a simple 2D image by the way, no animation) and its
> resolution ? For example, how can I specify that the output picture should be
> EXACTLY 5.43 inch x 3.24 inch, with 300 DPI resolution?

This is not supported by POV-Ray; you will have to calculate the proper
resolution (e.g. 5.43*300 = 1629 by 3.24*300 = 972 pixels), and then run the
image through an image-processing software such as Gimp, Photoshop or
what-have-you.


> Also, where and how do
> I change the output type, and instead of BMP get either TGA or TIFF ?

See section "3.1.2.4.1  Output File Type" in the POV-Ray 3.6 documentation. You
can enter the appropriate options (e.g. "+FT" for TGA) in the field to the
right of the resolution dropdown box.

That's also the box to use for ad-hoc custom resolutions. See section "3.1.2.2.1
 Height and Width of Output" for how to specify the resolution.

For instance, for a 5.43 x 3.24 inch image at 300 DPI in TGA format, you'd
specify "+FT +W1629 +H972". (But, as already said, you'd have to fix the DPIs
using an image processing tool.)


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From: Anthony D  Baye
Subject: Re: A problem regarding the size of the rentered image
Date: 17 Jun 2009 21:30:00
Message: <web.4a3997d7dd1514c231d6f4b0@news.povray.org>
POV renders strictly at 72 DPI, if you want to change this, you need to render
the image with a high resolution and then adjust its physical dimensions and
pixel depth in a program like photoshop.

for example:
a 5.43 X 3.24 image at 300 DPI would be rendered at
1644 x 972

The resulting image would be opened in photoshop, where you would go to the
"Image" menu, select "Image Size..." and change the Resolution to 300 dpi, turn
off "Resample Image" and click OK

The physical dimensions of the image are auto-scaled to the Resolution with the
given Pixel Dimensions.

as for changing the file type:

+FNd will give a d-bit (substitute d for 8, 16, 24 or 32 PNG file
+FTd will give a d-bit TGA file
+FJd will give a d-bit JPEG file

I don't think POV has TIFF output

"trexgr" <vic### [at] yahoocom> wrote:
> Hello all.
>
> I am completely new to rentering with pov-ray, and I have a question that is
> bugging me for a while today. After creating an image in VMD, I used the
> pov-ray rentering option, produced a .pov file, then used the pov-ray program
> in Windows, and produced a nice BMP file. I cannot, however have access to the
> size of the output file, and the resolution, i.e how many pixels per inch (DPI,
> or PPI) my output picture should be. I tried to check the Help, and I can change
> the width and the height of the image, in pixels (the program calls THIS as
> resolution, the output of 1024x780 pixels for example).
>
> This however is only a part of the solution. How can I have absolute control of
> the size of the image (its a simple 2D image by the way, no animation) and its
> resolution ? For example, how can I specify that the output picture should be
> EXACTLY 5.43 inch x 3.24 inch, with 300 DPI resolution? Also, where and how do
> I change the output type, and instead of BMP get either TGA or TIFF ?
>
> Thanks in advance
> t.


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From: trexgr
Subject: Re: A problem regarding the size of the rentered image
Date: 18 Jun 2009 02:00:06
Message: <web.4a39d6dddd1514ce3de2ae0@news.povray.org>
Thank you all VERY much for your valuable input! I now understand what I should
do!


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