imread 函数 的相关细节

第一个参数是图片的名称，如果是固定的，强烈建议使用/作为目录的分割符号

第二参数具有如下的值，说明了读取过程中是否需要进行像素的操作，例如取值0，表示读取过程中将像素转换为灰度值，默认参数是1， 表示不改变原图像的像素

enum ImreadModes {
IMREAD_UNCHANGED = -1, //!< If set, return the loaded image as is (with alpha channel, otherwise it gets cropped).
IMREAD_GRAYSCALE = 0, //!< If set, always convert image to the single channel grayscale image.
IMREAD_COLOR = 1, //!< If set, always convert image to the 3 channel BGR color image.
IMREAD_ANYDEPTH = 2, //!< If set, return 16-bit/32-bit image when the input has the corresponding depth, otherwise convert it to 8-bit.
IMREAD_ANYCOLOR = 4, //!< If set, the image is read in any possible color format.
IMREAD_LOAD_GDAL = 8, //!< If set, use the gdal driver for loading the image.
IMREAD_REDUCED_GRAYSCALE_2 = 16, //!< If set, always convert image to the single channel grayscale image and the image size reduced 1/2.
IMREAD_REDUCED_COLOR_2 = 17, //!< If set, always convert image to the 3 channel BGR color image and the image size reduced 1/2.
IMREAD_REDUCED_GRAYSCALE_4 = 32, //!< If set, always convert image to the single channel grayscale image and the image size reduced 1/4.
IMREAD_REDUCED_COLOR_4 = 33, //!< If set, always convert image to the 3 channel BGR color image and the image size reduced 1/4.
IMREAD_REDUCED_GRAYSCALE_8 = 64, //!< If set, always convert image to the single channel grayscale image and the image size reduced 1/8.
IMREAD_REDUCED_COLOR_8 = 65, //!< If set, always convert image to the 3 channel BGR color image and the image size reduced 1/8.
IMREAD_IGNORE_ORIENTATION = 128 //!< If set, do not rotate the image according to EXIF's orientation flag.
};

注意：
在进行图像的灰度值处理之后，默认情况下， 不会进行图像的直方图进行图像的增强，否则会出现运行异常
代码
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>

using namespace cv;

int main(int argc, char *argv[])
{
Mat image = imread("D:/20170601092226.png", 0);
if (image.empty())
{
std::cout << "打开图片失败,请检查" << std::endl;
return -1;
}
imshow("原图像", image);
waitKey();
return 0;
Mat imageRGB[3];
split(image, imageRGB);
for (int i = 0; i < 3; i++)
{
equalizeHist(imageRGB[i], imageRGB[i]);
}
merge(imageRGB, 3, image);
imshow("直方图均衡化图像增强效果", image);
waitKey();
return 0;
}