图像算法

一、简单的亮度和对比度调整

原理：new_image(i,j) = alpha*image(i,j) + beta

new_image.at<Vec3b>(y,x)[c] =saturate_cast<uchar>( alpha*( image.at<Vec3b>(y,x)[c] ) + beta );

注意使用到saturate_cast函数限幅
但Opencv有提供相应算法：image.convertTo(new_image, -1, alpha, beta);

二、给图像添加边界

#include "cv.h"
#include "highgui.h"

using namespace cv;
using namespace std;

int main(int argc,char *argv[])
{
	Mat src,dst;
	char type;

	src=imread("fish.jpg");
	imshow("src",src);
	
	while (true)
	{
		type=(char)waitKey(0);
		if (type=='c')
			copyMakeBorder(src,dst,(int)(0.05*src.rows),(int)(0.05*src.rows),(int)(0.05*src.cols),(int)(0.05*src.cols),BORDER_CONSTANT,Scalar(0,0,255));
		else if(type=='r')
			copyMakeBorder(src,dst,(int)(0.05*src.rows),(int)(0.05*src.rows),(int)(0.05*src.cols),(int)(0.05*src.cols),BORDER_REPLICATE);
		else break;
		imshow("dst",dst);
	}
	cvWaitKey(0);
	destroyAllWindows();
	return 0;
}