Am Mittwoch, 17. September 2008 01:43:45 schrieb Brendan Simons:
> On 16-Sep-08, at 4:50 AM, Stéfan van der Walt wrote:
> > I may be completely off base here, but you should be able to do this
> > *very* quickly using your GPU, or even just using OpenGL. Otherwise,
> > coding it up in ctypes is ea
Hey Brendan
2008/9/17 Brendan Simons <[EMAIL PROTECTED]>:
> I would love a c-types code snippet. I'm not very handy in c. Since
> I gather numpy is row-major, I thought I up and down crops very
> quickly by moving the start and end pointers of the array. For
> cropping left and right, is there
Thanks for the cogent response Fransesc. It's nice to know when
you're up against a "Really Hard Problem", rather than just missing
something obvious. I've started reading Ulrich Drepper report, and it
looks like a great place to start.
Cheers,
Brendan
On 17-Sep-08, at 5:34 AM, Frances
A Wednesday 17 September 2008, Brendan Simons escrigué:
[clip]
> I would love a c-types code snippet. I'm not very handy in c. Since
> I gather numpy is row-major, I thought I up and down crops very
> quickly by moving the start and end pointers of the array. For
> cropping left and right, is th
Brendan Simons wrote:
> Why would I need the GPU to do parallel operations? I thought most
> modern processors have vector units. I just don't know if there's a
> way to have my code use them.
Yes, modern CPU have vector units, but to use them efficiently, you have
to use assembly or specially w
On 16-Sep-08, at 4:50 AM, Stéfan van der Walt wrote:
> Hi Brendan
>
> 2008/9/16 brendan simons <[EMAIL PROTECTED]>:
>> #interpolate the green pixels from the bayer filter image ain
>> g = greenMask * ain
>> gi = g[:-2, 1:-1].astype('uint16')
>> gi += g[2:, 1:-1]
>> gi += g[1:-1, :-2]
>> gi += g[1
Why would I need the GPU to do parallel operations? I thought most
modern processors have vector units. I just don't know if there's a
way to have my code use them.
I tried a quick test with pyopengl (as quick as can be done in that
crazy api), but I found adding two textures of the same
Brendan,
Not sure if I understand correctly what you want, but ...
Numpy vector operations are performed in C, so there will be an iteration
over the array elements.
For parallel operations over all pixels, you'd need a package that talks to
your GPU, such as pyGPU.
I've never tried it and if yo
Hi Brendan
2008/9/16 brendan simons <[EMAIL PROTECTED]>:
> #interpolate the green pixels from the bayer filter image ain
> g = greenMask * ain
> gi = g[:-2, 1:-1].astype('uint16')
> gi += g[2:, 1:-1]
> gi += g[1:-1, :-2]
> gi += g[1:-1, 2:]
> gi /= 4
> gi += g[1:-1, 1:-1]
> return gi
I may be com
Hi everyone
I have a quick problem. I'm trying to write a routine to "demosaic" video data
extremely quickly. I thought my algorithm would make good use of my
processor's vector math units, but it isn't fast enough (it currently takes
about 300ms for each 8 megapixel frame) Maybe you can hel
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