# enum cv::ContourApproximationModes

## Overview

the contour approximation algorithm More…

#include <imgproc.hpp>

enum ContourApproximationModes
{
CHAIN_APPROX_NONE      = 1,
CHAIN_APPROX_SIMPLE    = 2,
CHAIN_APPROX_TC89_L1   = 3,
CHAIN_APPROX_TC89_KCOS = 4,
};


## Detailed Documentation

the contour approximation algorithm

### Enum Values

CHAIN_APPROX_NONE


stores absolutely all the contour points. That is, any 2 subsequent points (x1,y1) and (x2,y2) of the contour will be either horizontal, vertical or diagonal neighbors, that is, max(abs(x1-x2),abs(y2-y1))==1.

CHAIN_APPROX_SIMPLE


compresses horizontal, vertical, and diagonal segments and leaves only their end points. For example, an up-right rectangular contour is encoded with 4 points.

CHAIN_APPROX_TC89_L1


applies one of the flavors of the Teh-Chin chain approximation algorithm [81]

CHAIN_APPROX_TC89_KCOS


applies one of the flavors of the Teh-Chin chain approximation algorithm [81]