im_flat = im0[...,0]*65536 + im[...,1]*256 +im[...,2] colours = np.unique(im_flat)
Nadav ________________________________ From: numpy-discussion-boun...@scipy.org [numpy-discussion-boun...@scipy.org] On Behalf Of Tony Yu [tsy...@gmail.com] Sent: 15 January 2012 18:03 To: Discussion of Numerical Python Subject: Re: [Numpy-discussion] Counting the Colors of RGB-Image On Sun, Jan 15, 2012 at 10:45 AM, <a...@pdauf.de<mailto:a...@pdauf.de>> wrote: Counting the Colors of RGB-Image, nameit im0 with im0.shape = 2500,3500,3 with this code: tab0 = zeros( (256,256,256) , dtype=int) tt = im0.view() tt.shape = -1,3 for r,g,b in tt: tab0[r,g,b] += 1 Question: Is there a faster way in numpy to get this result? MfG elodw Assuming that your image is made up of integer values (which I guess they'd have to be if you're indexing into `tab0`), then you could write: >>> rgb_unique = set(tuple(rgb) for rgb in tt) I'm not sure if it's any faster than your loop, but I would assume it is. -Tony
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