2015-02-03 07:41:32 -0500 commented answer how do I transcribe this code from python to c++? thank you. I figured out the type of gaussian Numerator, it's CV_32FC1 as you mentioned. also I used Mat::mul operation instead of * and I got the same result as in python. 2015-02-03 07:10:43 -0500 commented answer how do I transcribe this code from python to c++? thank you, but what I really want to know is how to translate that to Opencv c++. what type should be gaussianNumerator ? Mat type ? PD: sorry for my poor english. 2015-02-03 07:07:04 -0500 received badge ● Editor (source) 2015-02-03 06:04:21 -0500 asked a question how do I transcribe this code from python to c++? Hello. I was looking how to segmenting license plate characters and I found this post where propose to use homomorphic filter. I am trying to transcribe the python code shown in the post but I don't know how to transcribe this part: # Create Gaussian mask of sigma = 10 M = 2*rows + 1 N = 2*cols + 1 sigma = 10 (X,Y) = np.meshgrid(np.linspace(0,N-1,N), np.linspace(0,M-1,M)) centerX = np.ceil(N/2) centerY = np.ceil(M/2) gaussianNumerator = (X - centerX)**2 + (Y - centerY)**2 # Low pass and high pass filters Hlow = np.exp(-gaussianNumerator / (2*sigma*sigma)) Hhigh = 1 - Hlow # Move origin of filters so that it's at the top left corner to # match with the input image HlowShift = scipy.fftpack.ifftshift(Hlow.copy()) HhighShift = scipy.fftpack.ifftshift(Hhigh.copy()) # Filter the image and crop If = scipy.fftpack.fft2(imgLog.copy(), (M,N)) Ioutlow = scipy.real(scipy.fftpack.ifft2(If.copy() * HlowShift, (M,N))) Iouthigh = scipy.real(scipy.fftpack.ifft2(If.copy() * HhighShift, (M,N)))  I found how to create a meshgrid in opencv in this post and I have already implemented it but I don't have any idea how to translate this to OpenCV/c++: gaussianNumerator = (X - centerX)**2 + (Y - centerY)**2  Would you please give me some ideas ? thank you very much. 2015-01-30 07:14:57 -0500 asked a question How do I threshold this Image correctly? Hello. I'm trying to threshold this image to get the characters more visible. I've used OTSU threshold but I don't get good results because when I convert the image to gray it is difficult to find a good threshold value. Would you please give me some ideas? Can I threshold an image on another colorspace ? thank you and sorry for my english.   