您如何从sip.voidptr（QImage.constBits（））转到ctypes void或char指针？

问题描述

我正在使用python，当然您不能很快遍历大图像的每个像素，因此我只能使用C DLL。

I'm using python and of course you can't loop through every pixel of a large image very quickly, so I defer to a C DLL.

I想要做这样的事情：

I want to do something like this:

img = QImage("myimage.png").constBits()
imgPtr = c_void_p(img)
found = ctypesDLL.myImageSearchMethod(imgPtr, width, height)

但是这行
imgPtr = c_void_p（img）
产量

But this line imgPtr = c_void_p(img)yelds

我不需要修改这些位。请教我您在这方面的绝地方式。

I don't need to modify the bits. Please teach me your Jedi ways in this area.

推荐答案

如， sip.voidptr .__ int __（）方法 p>

As stated here, sip.voidptr.__int__() method

c_void_p 说

因此您应该能够通过传递 sip.voidptr .__ int __（） c_void_p c $ c>方法构造函数：

So you should be able to build a c_void_p passing the return value of sip.voidptr.__int__() method to its constructor:

imgPtr = c_void_p(img.__int__())

我以此方式测试了此解决方案：

I tested this solution this way:

from PyQt5 import QtGui
from ctypes import *

lib = CDLL("/usr/lib/libtestlib.so")

image = QtGui.QImage("so.png")
bits = image.constBits()
bytes = image.bytesPerLine()
lib.f(c_void_p(bits.__int__()), c_int(image.width()), c_int(image.height()), c_int(bytes))

哪个功能可以正常工作，例如：

Which works fine with a function like:

#include <cstdio>
#include <QImage>
extern "C" {

    void f(unsigned char * c, int width, int height, int bpl)
    {
        printf("W:%d H:%d BPL:%d\n", width, height, bpl);
        QImage image(c, width, height, bpl, QImage::Format_RGB32);
        image.save("test.bmp");
    }
}

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