opencv，图像处理，rgb转换为hsv空间

图像RGB空间转换为HSV空间。
 H参数表示色彩信息，即所处的光谱颜色的位置。该参数用一角度量来表示，红、绿、蓝分别相隔120度。互补色分别相差180度。 
纯度S为一比例值，范围从0到1，它表示成所选颜色的纯度和该颜色最大的纯度之间的比率。S=0时，只有灰度。 
V表示色彩的明亮程度，范围从0到1。有一点要注意：它和光强度之间并没有直接的联系。

1: max=max(R,G,B)
2: min=min(R,G,B)
3: if R = max, H = (G-B)/(max-min)
4: if G = max, H = 2 + (B-R)/[b](max-min)
5: if B = max, H = 4 + (R-G)/(max-min)
6:
7: H = H * 60
8: if H < 0, H = H + 360
9:
10: V=max(R,G,B)
11: S=(max-min)/max
代码为：
//转换为HSV
void Rgb2Hsv(Mat &image, Mat &hsv)
{
float maxV = 0,minV = 0;
float V = 0, S = 0, H = 0;
float v = 0, s = 0, h = 0;
float R = 0, G = 0, B = 0;
float delta = 0, tmp = 0;

for (int i = 0; i < image.rows; i++)
{
for (int j = 0; j < image.cols; j++)
{
R = image.at<Vec3b>(i, j)[0];
G = image.at<Vec3b>(i, j)[1];
B = image.at<Vec3b>(i, j)[2];

R = R / 255.0;
B = B / 255.0;
G = G / 255.0;

tmp = min(R, G);
minV = min(tmp, B);
tmp = max(R, G);
maxV = max(tmp, B);
V = maxV; // v
delta = maxV - minV;
if (maxV != 0)
S = delta / maxV; // s
else
{

S = 0;

}
if (R == maxV)
H = (G - B) / delta;
else if (G == maxV)
H = 2 + (B - R) / delta;
else
H = 4 + (R - G) / delta;
H *= 60;
if (H < 0)
H += 360;

h = H / 2;
s = S * 255.0;
v = V * 255.0;

hsv.at<Vec3b>(i, j).val[0] = h;
hsv.at<Vec3b>(i, j).val[1] = s;
hsv.at<Vec3b>(i, j).val[2] = v;
}

}
}