Tracking Rectangles with Java/C++

[basicxman]

Originally Posted by Greg McKaskle

Just so there is no misunderstanding, the vision libraries that LabVIEW uses are equally accessible from C/C++. The NI product for C development is called LabWindows CVI, so the vision documentation with the CVI suffix is all about the C/C++ entry points.

So I've spent the morning looking around nivision.h, the "NI Vision for LabWindows/CVI Function Reference Help", and the old ellipsis tracking code to figure out tracking rectangles in C++. Here's a snippet of [entirely untested as I don't currently have access to a cRio] code.

void Camera::FindRectangles() {
    HSLImage  *rawImage  = camera.GetImage();
    MonoImage *monoImage = rawImage->GetLuminancePlane();
    Image     *image     = monoImage->GetImaqImage();
    workingImageWidth  = monoImage->GetWidth();
    workingImageHeight = monoImage->GetHeight();
    delete monoImage;
    delete rawImage;

    RectangleDescriptor *rectangleDescriptor = new RectangleDescriptor;
    rectangleDescriptor->minWidth  = 0;
    rectangleDescriptor->minHeight = 0;
    rectangleDescriptor->maxWidth  = workingImageWidth;
    rectangleDescriptor->maxHeight = workingImageHeight;

    int numCurrentMatches;
    RectangleMatch *temp;
    temp = imaqDetectRectangles(image,
                                rectangleDescriptor,
                                NULL, // Default curve options as per manual.
                                NULL, // Default shape detection options.
                                NULL, // (ROI) Whole image should be searched.
                                &numCurrentMatches);
    matches->erase(matches->begin(), matches->end());
    matches = new vector<RectangleMatch>;
    for (int i = 0; i < numCurrentMatches; i++)
        matches->push_back(temp[i]);
    
    imaqDispose(temp);
}

EDIT: CVI manual located at C:\Program Files (x86)\National Instruments\Vision\Documentation\VDM_CVI_User_Manu al.pdf

[scottbot95]

Would I be correct in assuming that in your example code, Camera is a class you made?

[basicxman]

Originally Posted by scottbot95

Would I be correct in assuming that in your example code, Camera is a class you made?

Yes, once we have our tracking code working completely and performing as we'd like, I'll likely post the full source code and an accompanying whitepaper.

[basicxman]

Originally Posted by basicxman

Here's a snippet of [entirely untested as I don't currently have access to a cRio] code.

Do not use this snippet! After I finally got to experiment with the camera for a while today, I've fixed some flaws in that script and found a better way of doing it entirely.