Re: Re: calling all uber geeks

Hi Dwayne,

I played with the generation of 3D from greyscale as well, way back then. The software I used was NIH
Image, a freebie written by Wayne Rasband of the National Institute of Health. It was used by scientists
all over the globe in processing images. Though not having been updated for a while, it is still very
useful and can be freely downloaded from:
      http://rsb.info.nih.gov/nih-image/

It can't replace Photoshop since it's primarily an 8 bit image processor, but I can guarantee that you
loads of fun, plus perhaps an insight on why medical images look the way they do. Besides generating
great looking 3D pictures of greyscale graphics, it also has a very cool histogram feature - it makes
histogram of any straight line that you draw. So, a student of mine wrote a macro and saved slices of
such histogram and made a 3D photo-sculpture out of them. Unfortunately he had to cut the pieces by
hand, but that was gosh a long long time ago, when monitors showed just black and white pixels...

Sam

>
> From: DWAYNE SANDALL <sandall@shaw.ca>
> Date: 2004/04/20 Tue AM 11:20:48 EDT
> To: alt-photo-process-l@sask.usask.ca
> Subject: Re: calling all uber geeks
>
> Barry,
>
> Here's my thinking on this, along with a couple of questions. First, the questions, if I recall correctly,
an stl file is a 3D file, and if that is correct, then what I am guessing you want to do is make a 'textured'
surface print? The rest of my comments are based on this assumption, of making this textured print.
>
> I think the answer you are looking for in this case might be in the realm of terrain mapping. When I
was in architecture school in the early/mid 90's I would take arial or sattelite images and be able to
make a 3D terrain model into which I could insert my 3D model of the building.
>
> Here's a bit of the theory of how it worked. The arial photos would be in greyscale, adjusted so that
pure white was the highest point of the ground, and pure black would be lowest, and the shades of
grey would be somewhere in between. The software would interpolate the pixels and build a 'mesh' that
would approximate the surface.
>
> Although the only time I made any physical 3D
> prototype was of a building model, and it was pretty cool to see something come out of the screen
into a piece of platic.
>
> Once, late at night in the school's computer lab, for kicks, I had taken a photo of my face and made a
mesh out of it.. it was pretty weird looking, but then again, some say I am too :-)
>
> As for software, I am a bit out of touch in this realm, as I last did anything like this in the late 90's,
but being the pack-rat that I am, I probably have some of the software backed up that I could refer to
and point you in the right direction.
>
> I hope this helps,
> Dwayne
Received on Tue Apr 20 19:00:41 2004