高斯平滑:
CV_EXPORTS_W void GaussianBlur( InputArray src, OutputArray dst, Size ksize,
double sigmaX, double sigmaY = 0,
int borderType = BORDER_DEFAULT );
改变图像大小:
CV_EXPORTS_W void resize( InputArray src, OutputArray dst,
Size dsize, double fx = 0, double fy = 0,
int interpolation = INTER_LINEAR );
颜色空间转换和阈值化:
CV_EXPORTS_W void cvtColor( InputArray src, OutputArray dst, int code, int dstCn = 0 );
CV_EXPORTS_W double threshold( InputArray src, OutputArray dst,
double thresh, double maxval, int type );