《学习OpenCV》第五章课后题5

题目说明：首先拍摄一张某场景的照片，然后摄像机不动，在此场景中心位置放一个咖啡杯，再拍摄一张照片，将其载入电脑并都转换为8位灰度图像。
a.取其差的绝对值并显示结果，它应该是一个带有噪声的咖啡杯掩码。
b.对结果图像进行二值化阈值操作，剔除噪声的同时并保留咖啡杯。超过阈值的像素应该设为255.显示结果。
c.在图像上进行CV_MOP_OPEN操作，以进一步清除噪声。

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>

using namespace cv;

int main()
{
    Mat img1 = imread("cup_1.jpg",CV_LOAD_IMAGE_GRAYSCALE);
    Mat img2 = imread("cup_2.jpg",CV_LOAD_IMAGE_GRAYSCALE);

    Mat abs_diff;
    absdiff(img1,img2,abs_diff);

    Mat thres_binary;
    threshold(abs_diff,thres_binary,20,255,THRESH_BINARY);

    Mat mop_open;
    Mat kernel = getStructuringElement(MORPH_RECT, Size(3,3), Point(-1,-1));
    morphologyEx(thres_binary,mop_open,MORPH_OPEN,kernel);

    imshow("abs_diff",abs_diff);
    imshow("thres_binary",thres_binary);
    imshow("mop_open",mop_open);

    imwrite("abs_diff.jpg",abs_diff);
    imwrite("thres_binary.jpg",thres_binary);
    imwrite("mop_open.jpg",mop_open);

    waitKey(0);
}