POV-Ray : Newsgroups : povray.binaries.images : multiple image_maps as media density-- 'fake' .df3 : Re: multiple image_maps as media density-- 'fake' .df3 Server Time
3 Dec 2024 21:57:26 EST (-0500)
  Re: multiple image_maps as media density-- 'fake' .df3  
From: yesbird
Date: 27 Oct 2024 05:41:02
Message: <671e0aae@news.povray.org>
On 27/10/2024 00:36, Kenneth wrote:
> A recent post by user 'yesbird' described using a .df3 media-density file made
> from a medical CT scan, and rendered in POV-ray...

Brilliant !
This is a very interesting and unusual experiment with surprisingly
excellent results - I even didn't know about such techniques. Looks like
now we can skip one step in preparing media data - it's very promising.
I did it with following commands before:

$ convert image-000001.dcm imgs.png
$ df3util create 512,1024,128 1 test
$   for i in $(seq 0 127) ; do df3util import test z:$i
$(printf "imgs-%d.png" $i) ; done

'df3util' written by jr works fine, but ImageMagic's 'convert' on
some platforms gives error processing jpeg, so I switched to:
$ dcmj2pnm image-000001.dcm  --write-png  > image-000001.png from dcmtk
package (sudo apt-get install dcmtk).

Maybe this utils will preserve 16-but color depth, I didn't check it.
Now there are two questions of interest for me:

1. Quality comparison of images, produced by both methods. I see that
color gradient on your images is not very smooth, compared to
traditional method, but maybe this is colormap dependent.

2. How it will work for isosurface approach (see attached
image):  https://povlab.online/?scene=dicom_iso.pov

I am continuing to think about a volume rendering service with Three.js
based GUI with POV on the server side and your method can simplify
implementation if we will not see quality degradation. In general DICOM
is a great source of data for volumes, thanks for displaying your
teeths, hope you will not need this operation in future.
--
YB


Post a reply to this message


Attachments:
Download 'dicom_iso.png' (97 KB)

Preview of image 'dicom_iso.png'
dicom_iso.png


 

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.