Programming Manual
PHYTEC Messtechnik GmbH 2008 L-720e_0
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Reading image data
DWORD GetPictureBufferAddress (WORD nDevNo, DWORD dwBitsSize) ;
dwBitsSize: size of the memory region used for the image
return value: address of the beginning of the memory region
In order to read the digitized data from the memory region controlled
by the VxD-driver, the user program must know the start address of
the memory region.
The function
GetPictureBufferAddress
returns this address to the user
program, at which the region of the memory starts, defined before by
the VxD. In this memory the Grabber stores the data of the digitized
image with the following structure:
(a) Only even- or only odd-fields are digitized
(the parameters of the dimension of the other field are zero)
The digitized field is placed at the beginning of the memory
region of the image.
(b) Even- and odd-fields are digitized
(nInterlaced=0)
The even-field is placed at the beginning of the memory
region. Adjacent to the even fields, the odd field is positioned.
The start address of the odd- field is also the start address of
the memory region of the image plus
nEhsize;
nEvsize
the
number of Byte per pixel.
(c) Frames are digitized in interlace-modus
(nInterlaced=1)
The digitized frame is composed of interlaced fields and begins
at the start address of the memory region of the image.
