# Thread Subject: help me resolve a question.Thanks a lot!

 Subject: help me resolve a question.Thanks a lot! From: yuhuijun Date: 17 May, 2006 23:02:44 Message: 1 of 5 I have a difficult question. Please help me.Thank you! I am trying to do a programme of 3D CED,I consult Rein van den Boomgaard's Algorithms for Non-Linear Diffusion. The question is only gaussian derivatives.The original programme is     function g = gD( f, scale, ox, oy )     % Gaussian (Derivative) Convolution         K = ceil( 3 * scale );         x = -K:K;         Gs = exp( - x.^2 / (2*scale^2) );         Gs = Gs / sum(Gs);         Gsx = gDerivative( ox, x, Gs, scale );         Gsy = gDerivative( oy, x, Gs, scale );         g = convSepBrd( f, Gsx, Gsy );     function r = gDerivative( order, x, Gs, scale )     switch order     case 0         r = Gs;     case 1         r = -x/(scale^2) .* Gs;     case 2         r = (x.^2-scale^2)/(scale^4) .* Gs;     otherwise         error('only derivatives up to second order are supported');     end The subfunction is     function g = convSepBrd( f, w1, w2 )     % convolve along colums + along rows with repetition of the border     N = size(f,1);     M = size(f,2);     K = (size(w1(:),1)-1)/2;     L = (size(w2(:),1)-1)/2;     iind = min(max((1:(N+2*K))-K,1),N);     jind = min(max((1:(M+2*L))-L,1),M);     fwb = f(iind,jind);     g=conv2(w1,w2,fwb,'valid'); I don't konw whether I consult above or not. The above is 2D gaussian derivatives,and I want to do the 3D gaussian derivatives.Please do me a favor!!! Thank you for your attention. I hope to hear from you.
 Subject: help me resolve a question.Thanks a lot! From: Sajid Khan Date: 7 May, 2012 16:21:06 Message: 2 of 5 can you please email me the file named gDerivative.m whose function you have mentioned in you query. my email address is sajidkhan7301@gmail.com yuhuijun wrote in message ... > I have a difficult question. > Please help me.Thank you! > I am trying to do a programme of 3D CED,I consult Rein van den > Boomgaard's Algorithms for Non-Linear Diffusion. > The question is only gaussian derivatives.The original programme is > function g = gD( f, scale, ox, oy ) > % Gaussian (Derivative) Convolution > K = ceil( 3 * scale ); > x = -K:K; > Gs = exp( - x.^2 / (2*scale^2) ); > Gs = Gs / sum(Gs); > Gsx = gDerivative( ox, x, Gs, scale ); > Gsy = gDerivative( oy, x, Gs, scale ); > g = convSepBrd( f, Gsx, Gsy ); > > function r = gDerivative( order, x, Gs, scale ) > switch order > case 0 > r = Gs; > case 1 > r = -x/(scale^2) .* Gs; > case 2 > r = (x.^2-scale^2)/(scale^4) .* Gs; > otherwise > error('only derivatives up to second order are supported'); > end > The subfunction is > function g = convSepBrd( f, w1, w2 ) > % convolve along colums + along rows with repetition of the > border > N = size(f,1); > M = size(f,2); > K = (size(w1(:),1)-1)/2; > L = (size(w2(:),1)-1)/2; > iind = min(max((1:(N+2*K))-K,1),N); > jind = min(max((1:(M+2*L))-L,1),M); > fwb = f(iind,jind); > g=conv2(w1,w2,fwb,'valid'); > I don't konw whether I consult above or not. > The above is 2D gaussian derivatives,and I want to do the 3D gaussian > derivatives.Please do me a favor!!! > Thank you for your attention. > I hope to hear from you.
 Subject: help me resolve a question.Thanks a lot! From: dpb Date: 7 May, 2012 16:34:29 Message: 3 of 5 On 5/7/2012 11:21 AM, Sajid Khan wrote: > can you please email me the file named gDerivative.m ... ... >> function r = gDerivative( order, x, Gs, scale ) >> switch order >> case 0 >> r = Gs; >> case 1 >> r = -x/(scale^2) .* Gs; >> case 2 >> r = (x.^2-scale^2)/(scale^4) .* Gs; >> otherwise >> error('only derivatives up to second order are supported'); >> end ... ??? --
 Subject: help me resolve a question.Thanks a lot! From: Sajid Khan Date: 9 May, 2012 13:09:07 Message: 4 of 5 Anyone please send me gDerivative.m as soon as possible, if anyone have it. my email address is sajidkhan7301@gmail.com
 Subject: help me resolve a question.Thanks a lot! From: Steven_Lord Date: 9 May, 2012 13:29:59 Message: 5 of 5 "Sajid Khan" wrote in message news:jodq9j\$hin\$1@newscl01ah.mathworks.com... > Anyone please send me gDerivative.m as soon as possible, if anyone have > it. > my email address is sajidkhan7301@gmail.com Read the post to which you replied. It includes gDerivative.m inside it. -- Steve Lord slord@mathworks.com To contact Technical Support use the Contact Us link on http://www.mathworks.com

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