Re: [Mesa3d-users] Fastest way to grab pixel values in to memory (and file)

[tom f. <tf...@al...>]

Brian Paul <br...@vm...> writes:
> Srimal Jayawardena wrote:
> > I'm working on a Image recognition project . . .
> > 
> > I am hoping to use OpenGL to obtain 2D pixel values from different 3D
> > view points, in the hope that the 3d h/w processing will do things a
> > lot faster for me.
[snip]
> > At the moment I am using glReadPixels() to read transformed pixel
> > values into memory.
> > 
> > Is  there a faster way? Or would you recommend a
> > better approach?

How complex is the image recognition algorithm?

You might consider implementing your algorithm in GLSL.  Then you'd do
one readback at the end just to get the result.  If your bottleneck is
the readback, you'd get much better performance.  Plus a modern GPU
will greatly accelerate the GLSL operations.

Cheers,

-tom