1 前备知识
图像直方图均衡化可以用于图像增强,对图像进行直方图均衡化处理,可提升后续对象检测的准确率,医学影像图像、卫星遥感图像、机器视觉产品图像均可通过直方图均衡化对图像质量进行提升,对比度增强。
2 所用到的主要OpenCv API
CV_EXPORTS_W void equalizeHist( InputArray src, OutputArray dst );
/** @brief Equalizes the histogram of a grayscale image.
The function equalizes the histogram of the input image using the following algorithm:
- Calculate the histogram \f$H\f$ for src .
- Normalize the histogram so that the sum of histogram bins is 255.
- Compute the integral of the histogram:
\f[H'_i = \sum _{0 \le j < i} H(j)\f]
- Transform the image using \f$H'\f$ as a look-up table: \f$\texttt{dst}(x,y) = H'(\texttt{src}(x,y))\f$
The algorithm normalizes the brightness and increases the contrast of the image.
@param src Source 8-bit single channel image.
@param dst Destination image of the same size and type as src .
*/
3 程序代码
#include <opencv2\opencv.hpp>
#include <iostream>
using namespace std;
using namespace cv;
int main(int argc, char** argv)
{
Mat src = imread("G:\\CVworkstudy\\program_wwx\\Research society140\\ZhaiZhigang140\\colormap.png");
if (src.empty())
{
printf("Could not load image...\n");
return -1;
}
namedWindow("input", WINDOW_AUTOSIZE);
Mat gray, dst;
cvtColor(src, gray, COLOR_BGR2GRAY);
imshow("input", gray);
equalizeHist(gray, dst);
imshow("eq", dst);
waitKey(0);
return 0;
}
4 运行结果


5 扩展及注意事项
null