[AstroPy] Image combine

[Derek Homeier]

On 7 Mar 2012, at 16:35, Tiago Ribeiro de Souza wrote:

> As far as I concern openCL is an attempt to provide a hardware-free sdk for GPU programming.  I agree that it is still far from being user-friendly, though. I am also not aware of any astronomical code widely distributed but, the tutorial in macresearch shows an application used in chemistry (I guess) that uses openCL for scientific computation. At the same time, it seems to me that, once you write parallelized code in openCL it works both with CPU and GPUs in the same way. 

That's highly unlikely, since even within openCL I expect you have to consider the 
type of hardware available to you, e.g. standard graphics cards will only provide 
significant speed-up for single-precision data, while the newest Tesla models 
(or successors) have double-precision vector registers. You might be able to code 
routines for both cases and multi-threading over several CPU cores, but again, this 
is probably best done at a lower level, as I'd expect a lot of these tasks are quite 
generic for image data or any kind of large arrays in 2 or more D. 
For rather simple tasks like addition/subtraction/division one would probably also 
have to carefully weigh the gain in CPU/GPU power against the overhead for moving 
these large amounts of data around.

Cheers,
							Derek