memory buffer transfer

[guimadox]

I would like to know if there is the possibility to have more information (or a piece of code) on the transfer of compressed images from a dataSource.

Suppose I want to emulate or to drive a scanner that is able to perform hardware compression (Jpeg, TIFFG4 … ).

I understand the I could use the buffered memory transfer through the triplet:

DG_IMAGE, DAT_IMAGEMEMXFER, MSG_GET and get the image in the buffer referenced by:
pMyXmemStruct->Memory.TheMem (*)

but the question is:

In my own DataSource, what should I write in the buffer? A Jpeg file with or without header? or what? And in the case of a a TIFFG4 image?

Thank you in advance

guimadox

(*) here are the data structures used by the buffered memory transfer

typedef struct {
TW_UINT16 Compression; /* How the data is compressed */
TW_UINT32 BytesPerRow; /* Number of bytes in a row of data */
TW_UINT32 Columns; /* How many columns */
TW_UINT32 Rows; /* How many rows */
TW_UINT32 XOffset; /* How far from the side of the image */
TW_UINT32 YOffset; /* How far from the top of the image */
TW_UINT32 BytesWritten; /* How many bytes written in Memory */
TW_MEMORY Memory; /* Mem struct used to pass actual image data */
} TW_IMAGEMEMXFER, FAR * pTW_IMAGEMEMXFER;

and:

typedef struct {
TW_UINT32 Flags; /* Any combination of the TWMF_ constants. */
TW_UINT32 Length; /* Number of bytes stored in buffer TheMem. */
TW_MEMREF TheMem; /* Pointer or handle to the allocated memory buffer. */
} TW_MEMORY, FAR * pTW_MEMORY;

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