Extract and save an image from a IplImage

Question

I'm working with a Ximea Camera, programming in c++ and using Ubuntu 14.04. I have a XI_IMG image and with the next conversion I'm creating an OpenCV image, copying data from xiAPI buffer to OpenCV buffer.

stat = xiGetImage(xiH, 5000, &image);
HandleResult(stat,"xiGetImage");    
XI_IMG* imagen = &image;

IplImage * Ima = NULL;
char fname_jpg[MAX_PATH] = "";
Ima = cvCreateImage(cvSize(imagen->width, imagen->height), IPL_DEPTH_8U, 1); 
memcpy(Ima->imageData, imagen->bp, imagen->width * imagen->height);

imwrite("image1", Ima);

After doing that I should be able to save or show the image, but the next error is shown:

program.cpp:76:24:error:invalid initialization of reference of type 'cv::InputArray {aka const cv::_InputArray&}' from expression of type 'IplImage* {aka IplImage*}'

Is there any other way to obtain or save the image? What else can I do to save a jpg image?

score 4 · Accepted Answer · answered Sep 22 '15 at 11:44

You are mixing old (and obsolete) C syntax like IplImage*, cv<SomeFunction>(), etc... with current C++ syntax. To make it work be consistent and use only one style.

Using IplImage

int main()
{
    IplImage* img = NULL;
    img = cvCreateImage(...);

    // Save 
    cvSaveImage("myimage.png", img);

    // Show
    cvShowImage("Image", img);
    cvWaitKey();

    return 0;
}

Or using new syntax (much better):

int main()
{
    Mat img(...);

    // Save 
    imwrite("myimage.png", img);

    // Show
    imshow("Image", img);
    waitKey();

    return 0;
}

Note that you don't need to memcpy the data after you initialize your Mat, but you can call one of these constructors:

C++: Mat::Mat(int rows, int cols, int type, void* data, size_t step=AUTO_STEP)
C++: Mat::Mat(Size size, int type, void* data, size_t step=AUTO_STEP)
C++: Mat::Mat(int ndims, const int* sizes, int type, void* data, const size_t* steps=0)

Last trick, you can wrap your IplImage in a Mat and then use imwrite:

Mat mat(Ima);
imwrite("name.ext", mat);

Extract and save an image from a IplImage

1 Answers1