wiasGetImageInformation - NtDoc
Native API online documentation, based on the System Informer
(formerly Process Hacker) phnt
headers
// wiamdef.h
HRESULT wiasGetImageInformation(
[in] BYTE *pWiasContext,
LONG lFlags,
[in, out] PMINIDRV_TRANSFER_CONTEXT pmdtc
);
View the official Windows Driver Kit DDI referenceNo description available.
The wiasGetImageInformation function retrieves transfer context information from an item.
pWiasContext [in]Pointer to a WIA item context.
lFlagsSpecifies operational flags. Currently, only the following flag is defined:
| Flag | Meaning |
|---|---|
| WIAS_INIT_CONTEXT | Initialize the MINIDRV_TRANSFER_CONTEXT structure. |
pmdtc [in, out]Pointer to a MINIDRV_TRANSFER_CONTEXT structure. Upon return, this structure contains the requested image item information.
On success, the function returns S_OK.
If the function fails, it returns a standard COM error or one of the WIA error codes.
This function uses a MINIDRV_TRANSFER_CONTEXT structure to calculate item image and item header sizes. In addition, it can optionally fill in an image header if the image format requires a data header. The header will be copied to the buffer if the pTransferBuffer member of the MINIDRV_TRANSFER_CONTEXT structure is not NULL. When using image formats (such as JPEG) that do not have a header, the header size in the lHeaderSize member of the MINIDRV_TRANSFER_CONTEXT structure is reported as zero.
For image formats where the actual final size of the image is not known until after data acquisition, as with multipage TIFF and compressed formats, the lItemSize member of the MINIDRV_TRANSFER_CONTEXT structure is reported as zero. The lImageSize member is reported as the size, in bytes, of the uncompressed image in a single page.
If WIAS_INIT_CONTEXT is specified in the lFlags parameter, the MINIDRV_TRANSFER_CONTEXT structure pointed to by the pmdtc parameter is filled in with information derived from the item's image properties. This flag should be used when a minidriver has allocated a new context.