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Retrieving Images
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Retrieving images
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Allocate a buffer and retrieve the current live image.

First, change data transfer to compression mode with “PUC_SetXferDataMode”.

.. code-block:: cpp

	result = PUC_SetXferDataMode(hDevice, PUC_DATA_COMPRESSED);
	if (PUC_CHK_FAILED(result))
	{
		_tprintf(_T("PUC_SetXferDataMode error:%u\n"), result);
		return;
	}

Next, retrieve the data size for the current resolution with “PUC_GetXferDataSize”.

.. code-block:: cpp

    result = PUC_GetXferDataSize(hDevice, PUC_DATA_COMPRESSED, &nDataSize);
    if (PUC_CHK_FAILED(result))
    {
    	return;
    }

.. note::
   - In the example above, the data size of the compressed image will be retrieved. Specify PUC_DATA_DECOMPRESSED_GRAY to retrieve the data size after converting to pixel data.
   - When allocating a buffer for the size retrieved with PUC_GetXferDataSize, the buffer will need to be reallocated every time the resolution is changed. Using PUC_GetMaxXferDataSize to allocate the maximum data size in advance facilitates this process.


Next, allocate a buffer and retrieve the image.

.. code-block:: cpp

    PUC_XFER_DATA_INFO xferData = { 0 };

    xferData.pData = new UINT8[nDataSize];

    result = PUC_GetSingleXferData(hDevice, &xferData);
    if (PUC_CHK_FAILED(result))
    {
        return;
    }

.. note::
   - The size of the actual transferred image is stored to xferData.nDataSize, and the sequence number is stored to xferData.nSequenceNo.
   - As the retrieved image has been compressed, it will need to be decoded in order to view it.


