Magick++ Issue when converting to Mat Opencv - c++

Question

Good day everyone,
I have this problem which I need to convert the Magick++ Image to OpenCV Mat. Though I successfully converted it however the problem occurs which the color of the Mat is not correct (Please see attached Image). In my case, I have a PDF file which I converted it to Magick++ Image page by page and to use my Image Processing methods, I need to convert it to OpenCV Mat. When I use other PDF file, the colors are correct. I really appreciate any help in this issue, Thanks.
My working code is displayed below, thanks.
Note: I use ImageMagick-7.0.6-Q16 and OpenCV 2.4.11
try {
string fName = "";
vector<Magick::Image> imageList;
cout << "Please Input the File name of the PDF." << endl;
cin >> fName;
cout << "Please wait while converting the PDF to Images...." << endl;
readImages(&imageList, fName);
bool isDecoded = false;
for (int i = 0; i < imageList.size(); i++){
if (!isDecoded){
int w = imageList[i].columns();
int h = imageList[i].rows();
Mat opencvImage(h,w,CV_8UC4);
imageList[i].write(0, 0, w, h, "RGBA" , Magick::CharPixel, opencvImage.data);
string decoded = QRScanner(opencvImage);
imshow("opencvImage", opencvImage);
if (decoded != ""){
cout << "Result: " << decoded << endl;
isDecoded = true;
}
waitKey();
}
}
}
catch (Magick::Exception &error_)
{
cout << "Caught exception: " << error_.what() << endl;
}
cout << "Convert Complete!" << endl;
system("pause");
Sample Code
Image Problem

Answer 1

I think the majority of the problem has been addressed in the comments above, but I believe this can be quickly fixed by adjusting the channel map to what OpenCV is expecting.
imageList[i].write(0, 0, w, h, "BGRA" , Magick::CharPixel, opencvImage.data);
^^^^
No need to worry about cvtColor or negation as you already can control how the data stream is exported.