这四个自定义函数的要怎么写?示范一下
时间: 2024-02-19 21:03:00 浏览: 22
好的,以下是四个自定义函数的代码实现:
1. 计算原始LBP特征的函数 `LBP`:
```
function [lbp_map] = LBP(img, R, P)
[h, w] = size(img);
lbp_map = zeros(h, w);
for i = R+1 : h-R
for j = R+1 : w-R
center = img(i, j);
code = 0;
for k = 0 : P-1
x = i + R * cos(2 * pi * k / P);
y = j - R * sin(2 * pi * k / P);
x1 = floor(x);
x2 = ceil(x);
y1 = floor(y);
y2 = ceil(y);
if x1 == x2 && y1 == y2
neighbor = img(x1, y1);
else
d1 = sqrt((x-x1)*(x-x1) + (y-y1)*(y-y1));
d2 = sqrt((x-x2)*(x-x2) + (y-y2)*(y-y2));
w1 = d2 / (d1 + d2);
w2 = d1 / (d1 + d2);
neighbor = w1 * img(x1, y1) + w2 * img(x2, y2);
end
if neighbor >= center
code = code + 2^k;
end
end
lbp_map(i, j) = code;
end
end
lbp_map = uint8(lbp_map);
end
```
2. 计算圆形LBP特征的函数 `circularLBP`:
```
function [lbp_map] = circularLBP(img, R, P)
[h, w] = size(img);
lbp_map = zeros(h, w);
for i = R+1 : h-R
for j = R+1 : w-R
center = img(i, j);
code = 0;
for k = 0 : P-1
x = i + R * cos(2 * pi * k / P);
y = j - R * sin(2 * pi * k / P);
x1 = floor(x);
x2 = ceil(x);
y1 = floor(y);
y2 = ceil(y);
if x1 == x2 && y1 == y2
neighbor = img(x1, y1);
else
d1 = sqrt((x-x1)*(x-x1) + (y-y1)*(y-y1));
d2 = sqrt((x-x2)*(x-x2) + (y-y2)*(y-y2));
w1 = d2 / (d1 + d2);
w2 = d1 / (d1 + d2);
neighbor = w1 * img(x1, y1) + w2 * img(x2, y2);
end
if neighbor >= center
code = code + 2^k;
end
end
lbp_map(i, j) = code;
end
end
lbp_map = uint8(lbp_map);
end
```
3. 计算旋转不变LBP特征的函数 `rotationInvariantLBP`:
```
function [lbp_map] = rotationInvariantLBP(img, R, P)
[h, w] = size(img);
lbp_map = zeros(h, w);
for i = R+1 : h-R
for j = R+1 : w-R
center = img(i, j);
code = 0;
for k = 0 : P-1
x = i + R * cos(2 * pi * k / P);
y = j - R * sin(2 * pi * k / P);
x1 = floor(x);
x2 = ceil(x);
y1 = floor(y);
y2 = ceil(y);
if x1 == x2 && y1 == y2
neighbor = img(x1, y1);
else
d1 = sqrt((x-x1)*(x-x1) + (y-y1)*(y-y1));
d2 = sqrt((x-x2)*(x-x2) + (y-y2)*(y-y2));
w1 = d2 / (d1 + d2);
w2 = d1 / (d1 + d2);
neighbor = w1 * img(x1, y1) + w2 * img(x2, y2);
end
if neighbor >= center
code = code + 2^k;
end
end
% 将LBP编码旋转到最小值
min_code = code;
for k = 1 : P-1
code = bitshift(code, 1);
if code >= 2^P
code = bitxor(code, 2^P);
code = bitor(code, 1);
end
if code < min_code
min_code = code;
end
end
lbp_map(i, j) = min_code;
end
end
lbp_map = uint8(lbp_map);
end
```
4. 计算旋转不变均匀LBP特征的函数 `uniformLBP`:
```
function [lbp_map] = uniformLBP(img, R, P)
[h, w] = size(img);
lbp_map = zeros(h, w);
for i = R+1 : h-R
for j = R+1 : w-R
center = img(i, j);
code = 0;
for k = 0 : P-1
x = i + R * cos(2 * pi * k / P);
y = j - R * sin(2 * pi * k / P);
x1 = floor(x);
x2 = ceil(x);
y1 = floor(y);
y2 = ceil(y);
if x1 == x2 && y1 == y2
neighbor = img(x1, y1);
else
d1 = sqrt((x-x1)*(x-x1) + (y-y1)*(y-y1));
d2 = sqrt((x-x2)*(x-x2) + (y-y2)*(y-y2));
w1 = d2 / (d1 + d2);
w2 = d1 / (d1 + d2);
neighbor = w1 * img(x1, y1) + w2 * img(x2, y2);
end
if neighbor >= center
code = code + 2^k;
end
end
% 将LBP编码旋转到最小值
min_code = code;
for k = 1 : P-1
code = bitshift(code, 1);
if code >= 2^P
code = bitxor(code, 2^P);
code = bitor(code, 1);
end
if code < min_code
min_code = code;
end
end
% 判断是否为均匀LBP
uniform = true;
for k = 1 : P-1
if bitget(min_code, k) ~= bitget(min_code, k+1)
uniform = false;
break;
end
end
if bitget(min_code, P) ~= bitget(min_code, 1)
uniform = false;
end
if uniform
lbp_map(i, j) = min_code;
else
lbp_map(i, j) = 2^P + 1;
end
end
end
lbp_map = uint8(lbp_map);
end
```
其中,`R`为LBP算法中的半径,`P`为LBP算法中的邻域点数。以上四个函数的实现代码可能有一定的参考价值,但需要注意的是,在实际应用中,还需要根据具体的需求做出一些修改和优化。