我对opencv很新... 我需要预测opencv.Wat中两个线性数据数组的值,我将为此做...例如我们在matlab中使用interp1函数。
tab =
1950 150.697
1960 179.323
1970 203.212
1980 226.505
1990 249.633
then the population in 1975, obtained by table lookup within the matrix tab, is
p = interp1(tab(:,1),tab(:,2),1975)
p =
214.8585
我们如何才能在opencv中这样做...请帮助我......谢谢。
答案 0 :(得分:2)
您可以尝试使用构建到OpenCV中的回归函数。但是对于简单的线性插值,你似乎正在做它可能更容易自己编写它。
double interpolate(int x1, double y1, int x2, double y2, int targetX)
{
int diffX = x2 - x1;
double diffY = y2 - y1;
int diffTarget = targetX - x1;
return y1 + (diffTarget * diffY) / diffX;
}
此函数线性插值给定给定数据点的目标值。
如果你想像matlab函数一样使用它,一次提供所有数据点,你需要一个选择两个最近邻居的函数。像这样:
double interpolate(Mat X, Mat Y, int targetX)
{
Mat dist = abs(X-targetX);
double minVal, maxVal;
Point minLoc1, minLoc2, maxLoc;
// find the nearest neighbour
Mat mask = Mat::ones(X.rows, X.cols, CV_8UC1);
minMaxLoc(dist,&minVal, &maxVal, &minLoc1, &maxLoc, mask);
// mask out the nearest neighbour and search for the second nearest neighbour
mask.at<uchar>(minLoc1) = 0;
minMaxLoc(dist,&minVal, &maxVal, &minLoc2, &maxLoc, mask);
// use the two nearest neighbours to interpolate the target value
double res = interpolate(X.at<int>(minLoc1), Y.at<double>(minLoc1), X.at<int>(minLoc2), Y.at<double>(minLoc2), targetX);
return res;
}
以下是一个显示如何使用它的小例子:
int main()
{
printf("res = %f\n", interpolate(1970, 203.212, 1980, 226.505, 1975));
Mat X = (Mat_<int>(5, 1) <<
1950, 1960, 1970, 1980, 1990);
Mat Y = (Mat_<double>(5, 1) <<
150.697, 179.323, 203.212, 226.505, 249.633);
printf("res = %f\n", interpolate(X, Y, 1975));
return 0;
}
我没有对此进行过广泛的测试。所以你可能需要修复一些错误。