This function returns a frame of image data and the feature descriptor for that frame.


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Controls and Indicators


      hCamera IN is the camera handle. This value is returned by Initialize.vi and is passed between Pixelink VIs as a reference.


       uBufferSize IN The size of the image buffer required in bytes. If Mode IN is set to UsePointer, uBufferSize should indicate the size of the buffer pointed to by pPixel IN. This buffer must be large enough to hold the requested image data.


       OutputMode IN Determines whether the data is passed in the form delivered by the camera (default), converted to RGB32 compatible with the NI IMAQ RGB image format or converted to a RGB24 buffer. Use RGB32 when connected to a Color camera in Raw8 (Bayer 8) or Raw16 (Bayer 16) mode with an IMAQ image type set to RGB. Use RGB32 when connected to a Color camera and using an array. Note that the buffer size required must be set for the number of RGB pixels at one byte per pixel. For monochrome cameras, use IMAQ Image types of MONO8 or MONO16 and set OutputMode IN to Default. OutputMode IN = RGB32 is relevant only if Mode In is set to UserPointer, OutputMode IN = RGB24 is relevant only if Mode IN is set to UserArray.


       Mode IN Determines whether GetNextFrame returns an array containing the image data or fills the data at a location indicated by Pixel IN. If set to UseArray, pPixel IN will be ignored. If set to UsePointer, then data OUT will be empty.


      pPixel IN A pointer to a image buffer of sufficient size to hold the image data. Ignored Mode IN is set to UseArray.


      pDescriptor A structure containing descriptive information about the frame returned from the camera. It contains the values of all camera settings used to capture the image. See the API reference manual for more information. 


      hCamera OUT has the same value as hCamera IN.


      uBufferSize OUT A pass-through of the uBufferSize IN variable.


     Data OUT An array of image data returned from the camera. The data will only be valid if Mode IN is set to UseArray. To interpret the data, check the PixeL Format settings in pDescriptor



Details


GetNextFrame returns the oldest image in the driver's image buffer.  If there is no image data in the buffer, GetNextFrame will wait until an image arrives.  The image buffer is circular and old images will be overwritten if not retrieved in a timely fashion.


To use with the IMAQ functions, use the VI IMAQ GetImagePixelPtr to generate a pixel pointer and pass this value to pPixel IN.


Note: See Error Handling for error input and output information and error codes.