[mikets]

Interestingly, I am trying to figure out what happened to GetHeight() and GetWidth if the camera is not ready. According to the source code:

/**
 * Gets the height of an image.
 * @return The height of the image in pixels.
 */
int ImageBase::GetHeight()
{
        int height;
        imaqGetImageSize(m_imaqImage, NULL, &height);
        return height;
}
/**
 * Gets the width of an image.
 * @return The width of the image in pixels.
 */
int ImageBase::GetWidth()
{
        int width;
        imaqGetImageSize(m_imaqImage, &width, NULL);
        return width;
}

Both height and width are uninitialized local variables and imaqGetImageSize could have failed. Since there is no source code to the nivision module so I can't tell if width and height will be zero initialized and both the GetHeight and GetWidth function do not check the return code of imaqGetImageSize.