opencv读取电脑桌面实时屏幕画面-----------------------opencv学习笔记

.h头文件
#pragma once

#include

#include

// 记住包含opencv目录
#include

// opencv_4.5.1 and contrib
#pragma comment(lib,“opencv_world454.lib”)
#pragma comment(lib,“opencv_world454d.lib”)

namespace _wss
{
/**
* 获取指定窗口句柄的mat
* @Param : h
*/
cv::Mat get_window_bits(HWND h);

/**
* 直接根据窗口进行截图
* @Param : name
* @Param : h
*/
cv::Mat screen_shot_by_window(std::string name);
cv::Mat screen_shot_by_window(HWND h);

}

.C源文件
#include “win32_screen_shots.h”

namespace _wss
{
cv::Mat get_window_bits(HWND h)
{
cv::Mat result;
HBITMAP bit = nullptr;
RECT rect{ 0 };
int width = 0, height = 0;
HDC hdc = nullptr, hdc_compatible = nullptr;
BITMAP info{ 0 };
int channels = 0;

	if (h == nullptr)
		return result;

	do
	{
		if (GetWindowRect(h, &rect) == FALSE)
			break;

		if (rect.left < 0)
			rect.left = 0;

		if (rect.top < 0)
			rect.top = 0;

		width = rect.right - rect.left;
		height = rect.bottom - rect.top;

		hdc = GetWindowDC(h);
		if (hdc == nullptr)
			break;

		hdc_compatible = CreateCompatibleDC(hdc);
		if (hdc_compatible == nullptr)
			break;

		bit = CreateCompatibleBitmap(hdc, width, height);
		if (bit == nullptr)
			break;

		SelectObject(hdc_compatible, bit);

		if (BitBlt(hdc_compatible, 0, 0, width, height, hdc, 0, 0, SRCCOPY) == FALSE)
			break;

		if (GetObjectA(bit, sizeof(BITMAP), &info) == 0)
			break;

		channels = info.bmBitsPixel == 1 ? 1 : info.bmBitsPixel / 8;
		result.create(cv::Size(info.bmWidth, info.bmHeight), CV_MAKETYPE(CV_8U, channels));
		if (GetBitmapBits(bit, info.bmHeight * info.bmWidth * channels, result.data) == 0)
			break;
	} while (false);

	if (hdc)
		ReleaseDC(h, hdc);

	if (hdc_compatible)
		DeleteDC(hdc_compatible);

	if (bit)
		DeleteObject(bit);

	return result;
}

cv::Mat screen_shot_by_window(HWND h)
{
	while (1)
	{
		return get_window_bits(h);
	}
	
}

cv::Mat screen_shot_by_window(std::string name)
{
	while (1)
	{
		return get_window_bits(FindWindowA(0, name.c_str()));
	}
	
}

}

测试文件

while (1)
{
	cv::Mat src = _wss::screen_shot_by_window(GetDesktopWindow());
	cv::waitKey(1);
	imwrite("D:/opencv/tu/小人.png", src);
	Mat dst = imread("D:/opencv/tu/小人.png");
	imshow("result", dst);
}