如何优化从PyCBitmap到OpenCV图像的转换 [英] How to optimize conversion from PyCBitmap to OpenCV image

问题描述

我有这段代码，它可以工作...但是运行速度很慢:

I've got this bit of code, and it works... But it runs very slow:

hwin = win32gui.GetDesktopWindow()
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(False)
img = np.array(signedIntsArray).astype(dtype="uint8") # This is REALLY slow!
img.shape = (height,width,4)

srcdc.DeleteDC()
memdc.DeleteDC()
win32gui.ReleaseDC(hwin, hwindc)
win32gui.DeleteObject(bmp.GetHandle())

return cv2.cvtColor(img, cv2.COLOR_RGBA2RGB)

此代码将捕获整个Windows桌面(均显示)，并将其转换为我以后使用的OpenCV映像.我认为，如果进行一些重新设计，此转换的运行速度可能会慢一些.具体来说，np.array(signedIntsArray)调用的确很慢！

This code grabs the entire windows desktop (both displays) and converts it to an OpenCV image that I use later. I believe this conversion is running slower than it could, if it was reworked a little. Specifically, the np.array(signedIntsArray) call is really slow!

有人想到如何更快地将桌面捕获转换为OpenCV图像吗?

Any thoughts on how to be a bit faster at converting a desktop capture into an OpenCV image?

推荐答案

首次使用Python.我想我对数据结构现在有了更好的了解.这是可以大大提高性能的解决方案:

First time working with Python. I think I have a better understanding of now of the data structures. Here's the fix that drastically improves performance:

更改:

signedIntsArray = bmp.GetBitmapBits(False)
img = np.array(signedIntsArray).astype(dtype="uint8")

收件人:

signedIntsArray = bmp.GetBitmapBits(True)
img = np.fromstring(signedIntsArray, dtype='uint8')

速度大大提高了！

这是因为np库从字符串创建数组比从元组创建数组要快得多.

This is because it's a lot faster for the np library to create an array from a string than from a tuple.

这篇关于如何优化从PyCBitmap到OpenCV图像的转换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IT屋！