Following line makes otsu thresholding operation: cv::threshold(im_gray, img_bw, 0, 255, CV_THRESH_BINARY | CV_THRESH_OTSU); im_gray is a source 8-bit image, img_bw is a result, 0 means threshold level which actually is omitted because we used CV_THRESH_OTSU flag, 255 is a value that is going to be assigned to respectively pixels in the result (namely, to all … Read more
b = a[a>threshold] this should do I tested as follows: import numpy as np, datetime # array of zeros and ones interleaved lrg = np.arange(2).reshape((2,-1)).repeat(1000000,-1).flatten() t0 = datetime.datetime.now() flt = lrg[lrg==0] print datetime.datetime.now() – t0 t0 = datetime.datetime.now() flt = np.array(filter(lambda x:x==0, lrg)) print datetime.datetime.now() – t0 I got $ python test.py 0:00:00.028000 0:00:02.461000 http://docs.scipy.org/doc/numpy/user/basics.indexing.html#boolean-or-mask-index-arrays