def grab_screen(region=None): hwin = win32gui.GetDesktopWindow() if region: left, top, x2, y2 = region width = x2 - left + 1 height = y2 - top + 1 else: width = win32api.GetSystemMetrics(win32con.SM_CXVIRTUALSCREEN) height = win32api.GetSystemMetrics(win32con.SM_CYVIRTUALSCREEN) left = win32api.GetSystemMetrics(win32con.SM_XVIRTUALSCREEN) top = win32api.GetSystemMetrics(win32con.SM_YVIRTUALSCREEN) hwindc = win32gui.GetWindowDC(hwin) srcdc = win32ui.CreateDCFromHandle(hwindc) memdc = srcdc.CreateCompatibleDC() bmp = win32ui.CreateBitmap() bmp.CreateCompatibleBitmap(srcdc, width, height) memdc.SelectObject(bmp) memdc.BitBlt((0, 0), (width, height), srcdc, (left, top), win32con.SRCCOPY) signedIntsArray = bmp.GetBitmapBits(True) img = np.fromstring(signedIntsArray, dtype='uint8') img.shape = (height, width, 4) srcdc.DeleteDC() memdc.DeleteDC() win32gui.ReleaseDC(hwin, hwindc) win32gui.DeleteObject(bmp.GetHandle()) return cv2.cvtColor(img, cv2.COLOR_BGRA2BGR)
时间: 2024-04-20 12:24:02 浏览: 170
这段代码是用于截取屏幕区域的图像,并将其转换为OpenCV的BGR格式。它使用了`win32gui`、`win32api`和`win32ui`等库来实现。具体的步骤如下:
1. 获取当前窗口的句柄:`hwin = win32gui.GetDesktopWindow()`
2. 根据给定的区域参数计算截取图像的宽度、高度和起始点坐标(如果没有指定区域,则获取整个屏幕的参数)。
3. 获取窗口设备上下文:`hwindc = win32gui.GetWindowDC(hwin)`
4. 创建与窗口设备上下文兼容的内存上下文:`srcdc = win32ui.CreateDCFromHandle(hwindc)`
5. 创建一个与内存上下文兼容的位图对象:`bmp = win32ui.CreateBitmap()`
6. 创建一个与位图对象兼容的内存上下文:`memdc = srcdc.CreateCompatibleDC()`
7. 将位图对象与内存上下文关联:`memdc.SelectObject(bmp)`
8. 使用位块传输函数(BitBlt)将屏幕图像复制到位图对象中:`memdc.BitBlt((0, 0), (width, height), srcdc, (left, top), win32con.SRCCOPY)`
9. 获取位图对象的像素数据并转换为NumPy数组:`signedIntsArray = bmp.GetBitmapBits(True); img = np.fromstring(signedIntsArray, dtype='uint8')`
10. 调整数组形状以匹配图像的高度、宽度和通道数:`img.shape = (height, width, 4)`
11. 释放资源,删除对象:`srcdc.DeleteDC(); memdc.DeleteDC(); win32gui.ReleaseDC(hwin, hwindc); win32gui.DeleteObject(bmp.GetHandle())`
12. 将图像从BGRA格式转换为BGR格式:`return cv2.cvtColor(img, cv2.COLOR_BGRA2BGR)`
这个函数可以方便地在Windows环境下截取屏幕图像,并使用OpenCV进行后续处理。
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