nikie wrote: > Chaos wrote: > > > As my first attempt to loop through every pixel of an image, I used > > > > for thisY in range(0, thisHeight): > > for thisX in range(0, thisWidth): > > #Actions here for Pixel thisX, thisY > > > > But it takes 450-1000 milliseconds > > > > I want speeds less than 10 milliseconds > > Milliseconds don't mean much unless we knew how big your images are and > what hardware you're using. > > Have you considered using NumPy? Assuming you can get the image into a > numpy array efficiently, the actual algorithm boils down to something > like this: > > grey = r*0.3 + g*0.59 + b*0.11 > index = grey.argmin() > x,y = index%step, index/step > v = grey[x,y] > > where r,g,b and grey are numpy.ndarray objects; The arithmetic > operators and the argmin-function are implemented in C, so you can > expect decent performance. (the 4 lines above take about 80 ms for a > 1000x1000 image on my PC) > > If that's not enough, you might want to use some specially optimized C > library for this purpose. (I'd suggest Intel's IPP, but there are > others).
Can you give me an example of geting an image into a numpy array? -- http://mail.python.org/mailman/listinfo/python-list
