I've tried matching up the depth flags of the screenshot and the template/result Mats, and the best case scenario is that I am able to display all 3 images, but the template matching doesn't work because I'm assuming the source (screenshot) image is displayed in color whilst the others are in grayscale. Other conversions either fail, or display strange results and fail the template matching (or simply raise an error)... And changing the screenshot image's Mat to use any other depth flag ends up displaying the image incorrectly.

如何利用 OpenCV 的模板匹配 C++ 中的屏幕截图?我应该对屏幕截图图像进行某种手动转换吗?

What can I do to utilize OpenCV's template matching with a screenshot taken in C++? Is there some sort of manual conversion I should be doing to the screenshot image, or something?

截屏代码取自:github.com/acdx/opencv-screen-capture
我的主要代码:codeshare.io/vLio1

推荐答案

我已经包含了用于从桌面图像中查找模板图像的代码.希望这能解决您的问题！

I have included my code for finding a Template image from your Desktop image. Hope this solves your problem!

#include <fstream>
#include <memory>
#include <string>
#include <iostream>
#include <strstream>
#include <functional>
#include <Windows.h>
#include <iostream>
#include <string>

using namespace std;
using namespace cv;

Mat hwnd2mat(HWND hwnd){

    HDC hwindowDC,hwindowCompatibleDC;

    int height,width,srcheight,srcwidth;
    HBITMAP hbwindow;
    Mat src;
    BITMAPINFOHEADER  bi;

    hwindowDC=GetDC(hwnd);
    hwindowCompatibleDC=CreateCompatibleDC(hwindowDC);
    SetStretchBltMode(hwindowCompatibleDC,COLORONCOLOR);  

    RECT windowsize;    // get the height and width of the screen
    GetClientRect(hwnd, &windowsize);

    srcheight = windowsize.bottom;
    srcwidth = windowsize.right;
    height = windowsize.bottom;  //change this to whatever size you want to resize to
    width = windowsize.right;

    src.create(height,width,CV_8UC4);

    // create a bitmap
    hbwindow = CreateCompatibleBitmap( hwindowDC, width, height);
    bi.biSize = sizeof(BITMAPINFOHEADER);    //http://msdn.microsoft.com/en-us/library/windows/window/dd183402%28v=vs.85%29.aspx
    bi.biWidth = width;    
    bi.biHeight = -height;  //this is the line that makes it draw upside down or not
    bi.biPlanes = 1;    
    bi.biBitCount = 32;    
    bi.biCompression = BI_RGB;    
    bi.biSizeImage = 0;  
    bi.biXPelsPerMeter = 0;    
    bi.biYPelsPerMeter = 0;    
    bi.biClrUsed = 0;    
    bi.biClrImportant = 0;

    // use the previously created device context with the bitmap
    SelectObject(hwindowCompatibleDC, hbwindow);
    // copy from the window device context to the bitmap device context
    StretchBlt( hwindowCompatibleDC, 0,0, width, height, hwindowDC, 0, 0,srcwidth,srcheight, SRCCOPY); //change SRCCOPY to NOTSRCCOPY for wacky colors !
    GetDIBits(hwindowCompatibleDC,hbwindow,0,height,src.data,(BITMAPINFO *)&bi,DIB_RGB_COLORS);  //copy from hwindowCompatibleDC to hbwindow

    // avoid memory leak
    DeleteObject (hbwindow); DeleteDC(hwindowCompatibleDC); ReleaseDC(hwnd, hwindowDC);

    return src;
}

bool NMultipleTemplateMatching(Mat mInput,Mat mTemplate,float Threshold,float Closeness,vector<Point2f> &List_Matches)
{
    Mat mResult;
    Size szTemplate= mTemplate.size();
    Size szTemplateCloseRadius((szTemplate.width/2)* Closeness,(szTemplate.height/2)* Closeness);

    matchTemplate(mInput, mTemplate, mResult, TM_CCOEFF_NORMED);
    threshold(mResult, mResult, Threshold, 1.0, THRESH_TOZERO);
    while (true) 
    {
        double minval, maxval ;
        Point minloc, maxloc;
        minMaxLoc(mResult, &minval, &maxval, &minloc, &maxloc);

        if (maxval >= Threshold)
        {
            List_Matches.push_back(maxloc);
            rectangle(mResult,Point2f(maxloc.x-szTemplateCloseRadius.width,maxloc.y-szTemplateCloseRadius.height),Point2f(maxloc.x+szTemplateCloseRadius.width,maxloc.y+szTemplateCloseRadius.height),Scalar(0),-1);
        }
        else
            break;
    }
    //imshow("reference", mDebug_Bgr);
    return true;
}


int main(int argc, char** argv)
{
    Mat mTemplate_Bgr,mTemplate_Gray;
    mTemplate_Bgr= imread("Template.png",1);
    imshow("mTemplate_Bgr",mTemplate_Bgr);

    HWND hDesktopWnd;
    hDesktopWnd=GetDesktopWindow();
    Mat mScreenShot= hwnd2mat(hDesktopWnd);
    Mat mSource_Gray,mResult_Bgr= mScreenShot.clone();


    float Threshold= 0.9;
    float Closeness= 0.9;
    vector<Point2f> List_Matches;

    cvtColor(mScreenShot,mSource_Gray,COLOR_BGR2GRAY);
    cvtColor(mTemplate_Bgr,mTemplate_Gray,COLOR_BGR2GRAY);

    namedWindow("Screen Shot",WINDOW_AUTOSIZE);
    imshow("Screen Shot",mSource_Gray);

    NMultipleTemplateMatching(mSource_Gray,mTemplate_Gray,Threshold,Closeness,List_Matches);

    for (int i = 0; i < List_Matches.size(); i++)
    {
        rectangle(mResult_Bgr,List_Matches[i],Point(List_Matches[i].x + mTemplate_Bgr.cols, List_Matches[i].y + mTemplate_Bgr.rows),Scalar(0,255,0), 2);
    }

    imshow("Final Results",mResult_Bgr);

    waitKey(0);

    return 0;
}   

这篇关于来自窗口屏幕截图的模板匹配的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！