opencv 简单的实现局部阈值处理

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/qq_38204686/article/details/79284063

//局部阈值处理  3x3
void adaptiveThreshold(Mat &img,double b)
{
	Mat im;
	im = img.clone();
	int i,j,k;
	//行列
	int row = img.rows;
	int col = img.cols;
	//8邻域、均值
	uchar n[9];
	double m;
	//遍历图像
	uchar *p0,*pp,*p1,*p;
	for(i = 1; i < row-1; ++i)  
    {
		//读取图像数据
		p0 = im.ptr<uchar>(i-1); 
        pp = im.ptr<uchar>(i);  
		p1 = im.ptr<uchar>(i+1);
        //修改原图
		p = img.ptr<uchar>(i);
        for (j = 1; j < col-1; ++j)  
        {
			m = 0;
			//3x3 八邻域
            n[0] = p0[j-1];
			n[1] = p0[j];
			n[2] = p0[j+1];
			n[3] = pp[j-1];
			n[4] = pp[j];
			n[5] = pp[j+1];
			n[6] = p1[j-1];
			n[7] = p1[j];
			n[8] = p1[j+1];
			//计算均值
			for(k = 0;k < 9;k++)
			{
				m += n[k];
			}
			m = m / 9 - b;
			if(n[4] > m)
				p[j] = 255;
			else
				p[j] = 0;
        }  
    }
	im.release();
}