[SciPy-User] Projecting volumes down to 2D

[Chris Weisiger]

On Thu, Sep 1, 2011 at 8:15 AM, Chris Weisiger <cweisiger at msg.ucsf.edu> wrote:
> On Thu, Sep 1, 2011 at 1:34 AM, Christoph Gohlke <cgohlke at uci.edu> wrote:
>>
>> This looks like "maximum intensity projection" visualization
>> <http://en.wikipedia.org/wiki/Maximum_intensity_projection>. MIP can be
>> efficiently implemented using OpenGL by blending together multiple
>> slices, oriented perpendicular to the projection direction, through a 3D
>> texture (xyz data). Also consider VTK's vtkVolumeRayCastMIPFunction class.
>
> Interesting, and I didn't know that OpenGL could do that. However, I'd
> already considered and rejected using 3D textures for the application
> as a whole, because my image data can be so large -- upwards of
> 512x512x60 for a single timepoint, and not only can there be many
> timepoints, but users can also request projections through time. So we
> could be talking gigabytes of texture data here. Currently this
> program runs well on my rather underpowered laptop, and I'd like to
> keep things that way if possible.

Just to followup, the maximum size of a 3D texture on this laptop is
only 128 pixels in any direction, so I'd have to do some nasty
stitching together of texture blocks to use OpenGL to solve this
problem. Nice idea, though. Of course, practically every computer here
is more powerful than my laptop, but they don't always have unusually
strong graphics cards, and I'd rather not restrict what computers my
code can run on.

-Chris