inline Vec3f sqr(const Vec3b& a)
{
return Vec3f(CV_8TO32F_SQR(a[0]), CV_8TO32F_SQR(a[1]), CV_8TO32F_SQR(a[2]));
}
template<> inline double sqr(uchar a) { return CV_8TO32F_SQR(a); }
inline float sqr(uchar a) { return CV_8TO32F_SQR(a); }