到目前为止，我的代码是:
function imgg = derichefilter1(x, k, a, b, c)
osize = size(x);
x = double(x);
a = double(a);
b = double(b);
c = double(c);
k = double(k);
y1 = zeros(osize(1),osize(2));
y2 = zeros(osize(1),osize(2));
y1(:,1) = a(1)*x(:,1);
y1(:,2) = a(1)*x(:,2) + a(2)*x(:,1) + b(1)*y1(:,1);
for ii=3:osize(2)
y1(:,ii) = a(1)*x(:,ii) + a(2)*x(:,ii-1) + b(1)*y1(:,ii-1) + b(2)*y1(:,ii-2);
end
y2(:,osize(2)-1) = a(3)*x(osize(2));
for ii=(osize(2)-2):-1:1
y2(:,ii) = a(3)*x(:,ii+1) + a(4)*x(:,ii+2) + b(1)*y2(:,ii+1) + b(2)*y2(:,ii+2);
end
imgg = c*(y1+y2);
function imgg = derichefilter2(x, k, a, b, c)
imgg = derichefilter1(x,k,a(1:4),b,c(1));
imgg = (derichefilter1(imgg',k,a(5:8),b,c(2)))';
function [mask magn] = nonmaxsupp(x, y)
magn = sqrt(x.^2 + y.^2);
argu = atan2(y,x);
argu = argu/pi*4;
argu = int32(round(argu));
argu(argu == 4) = 0;
argu(argu < 0) = argu(argu < 0) + 4;
mask = boolean(zeros(size(x)));
for ii = 2:(size(x,1)-1)
for jj = 2:(size(x,2)-1)
switch argu(ii,jj)
case 0
mask(ii,jj) = (max(magn(ii,jj+1),magn(ii,jj-1)) <= magn(ii,jj));
case 1
mask(ii,jj) = (max(magn(ii-1,jj+1),magn(ii+1,jj-1)) <= magn(ii,jj));
case 2
mask(ii,jj) = (max(magn(ii-1,jj),magn(ii+1,jj)) <= magn(ii,jj));
case 3
mask(ii,jj) = (max(magn(ii+1,jj+1),magn(ii-1,jj-1)) <= magn(ii,jj));
end
end
end
function imgg = hystthres(x,Tl,Th)
imgg = (x>Th);
limg = (x>=Tl);
osize = size(x);
nTh = 0;
for ii = 1:osize(1)
for jj = 1:osize(2)
if imgg(ii,jj)
nTh = nTh + 1;
end
end
end
c = zeros(1,nTh); r = zeros(1,nTh); nTh=0;
for ii = 1:osize(1)
for jj = 1:osize(2)
if imgg(ii,jj)
nTh = nTh + 1;
c(nTh) = ii; r(nTh) = jj;
end
end
end
imgg = bwselect(limg,r,c,8);
function imgg = derichecomplete(x, alph, Tl, Th)
k = (1 - exp(-alph))^2/(1 + 2*alph*exp(-alph) - exp(-2*alph));
as = zeros(1,8);
as(1) = k;
as(2) = k*exp(-alph)*(alph-1);
as(3) = k*exp(-alph)*(alph+1);
as(4) = -k*exp(-2*alph);
as(5:8)=as(1:4);
b = zeros(1,2);
b(1) = 2*exp(-alph);
b(2) = -exp(-2*alph);
cs = [1,1];
ax = [0,1,-1,0,as(5:8)];
cx = [-(1 - exp(-alph))^2,1];
ay = [ax(5:8),ax(1:4)];
cy = [cx(2) cx(1)];
deriches = derichefilter2(x, k, as, b, cs);
derichex = derichefilter2(deriches, k, ax, b, cx);
derichey = derichefilter2(deriches, k, ay, b, cy);
[mask mag] = nonmaxsupp(derichex, derichey);
mag(~mask) = 0;
imgg = hystthres(mag,Tl,Th);
clc; clear all; close all;
imagepath = input('Enter the image path in single quotes: ');
alph = input('Enter the value of alpha to be used: ');
Tl = input('Enter the value of Tl to be used: ');
Th = input('Enter the value of Th to be used: ');
imgg = imread(imagepath);
szzz = size(size(imgg));
if szzz(2) == 3
osize = size(imgg);
hystf = boolean(zeros(osize(1:2)));
for ii=1:3
hystf = hystf | derichecomplete(imgg(:,:,ii),alph,Tl,Th);
end
else
hystf = derichecomplete(imgg,alph,Tl,Th);
end
imshow(hystf);
我在Canny-Deriche Wikipedia page上的图像上的输出
我似乎找不到错误，因为我按照那里的说明和在Canny edge detector页面上的指示进行操作。我只是按原样实现了算法，但似乎仍然无法产生相同的输出。这些功能既浓密又前卫，而不是像Wikipedia页面上那样平滑。
编辑:Dropbox link编码/图像，因此您不必复制/粘贴它。
最佳答案
我认为您未处理正确的文件。我将您的函数应用于全分辨率图像http://upload.wikimedia.org/wikipedia/commons/5/5e/Sunflowers_in_July.jpg，结果看起来不错
如果将您的功能应用于50K预览文件，则会得到上面显示的结果。
关于algorithm - 在我的Canny-Deriche的MATLAB实现中无法获得干净的输出，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/14132356/