OpenCV函数学习——distancetransform函数各参数解释及使用 （距离变换）

OpenCV函数学习——distancetransform函数之距离变换

Opencv中distanceTransform方法用于计算图像中每一个非零点距离离自己最近的零点的距离，distanceTransform的第二个Mat矩阵参数dst保存了每一个点与最近的零点的距离信息，图像上越亮的点，代表了离零点的距离越远。

官方文档

/** @overload @param src 8-bit, single-channel (binary) source image. @param dst Output image with calculated distances. It is a 8-bit or 32-bit floating-point, single-channel image of the same size as src . @param distanceType Type of distance, see #DistanceTypes @param maskSize Size of the distance transform mask, see #DistanceTransformMasks. In case of the #DIST_L1 or #DIST_C distance type, the parameter is forced to 3 because a \f3\times 3\f mask gives the same result as \f5\times 5\f or any larger aperture. @param dstType Type of output image. It can be CV_8U or CV_32F. Type CV_8U can be used only for the first variant of the function and distanceType == #DIST_L1. */

CV_EXPORTS_W void distanceTransform( InputArray src, OutputArray dst,
                                     int distanceType, int maskSize, int dstType=CV_32F);




enum DistanceTypes {
    DIST_USER    = -1,  //!< User defined distance
    DIST_L1      = 1,   //!< distance = |x1-x2| + |y1-y2|
    DIST_L2      = 2,   //!< the simple euclidean distance
    DIST_C       = 3,   //!< distance = max(|x1-x2|,|y1-y2|)
    DIST_L12     = 4,   //!< L1-L2 metric: distance = 2(sqrt(1+x*x/2) - 1))
    DIST_FAIR    = 5,   //!< distance = c^2(|x|/c-log(1+|x|/c)), c = 1.3998
    DIST_WELSCH  = 6,   //!< distance = c^2/2(1-exp(-(x/c)^2)), c = 2.9846
    DIST_HUBER   = 7    //!< distance = |x|<c ? x^2/2 : c(|x|-c/2), c=1.345
};

应用参考：Opencv距离变换distanceTransform应用——细化字符轮廓&&查找物体质心