IG_save_mem_CB

This function saves the image referenced by hIGear to a memory buffer using user-defined callback functions.

Declaration:

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AT_ERRCOUNT ACCUAPI IG_save_mem_CB_ex( LPVOID lpImage, AT_UINT nImageSize, AT_UINT nBufferSize, UINT nPage, UINT nReserved, AT_LMODE lFormatType, LPFNIG_RASTER_GET lpfnRasterGet, LPFNIG_DIB_GET_EX lpfnDIBGetEx, LPVOID lpPrivateData, LPAT_UINT lpActualSize );

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AT_ERRCOUNT ACCUAPI IG_save_mem_CB_ex(
   LPVOID lpImage,
   AT_UINT nImageSize,
   AT_UINT nBufferSize,
   UINT nPage,
   UINT nReserved,
   AT_LMODE lFormatType,
   LPFNIG_RASTER_GET lpfnRasterGet,
   LPFNIG_DIB_GET_EX lpfnDIBGetEx,
   LPVOID lpPrivateData,
   LPAT_UINT lpActualSize
);

Arguments:

Name	Type	Description
lpImage	LPVOID	Memory buffer to which to save the image.
nImageSize	AT_UINT	Size of the image if it already exists in the buffer, 0 otherwise.
nBufferSize	AT_UINT	Size of the memory buffer.
nPage	UINT	If saving to a multi-page file, set this to the page number to insert this page as. Note that page numbers begin at 1, not 0. Otherwise set to 1.
nReserved	UINT	Reserved, should be set to 0 for now.
lFormatType	AT_LMODE	Specifies the format to use for saving, and also the compression scheme if applicable. See enumIGSaveFormats.
lpfnRasterGet	LPFNIG_RASTER_GET	Pointer to a function of type LPFNIG_RASTER_GET, which will be called for each raster line of the image, before that line is saved.
lpfnDIBGetEx	LPFNIG_DIB_GET	Pointer to a function of type LPFNIG_DIB_GET, which will be called just prior to saving the DIB header.
lpPrivateData	LPVOID	Pointer to a private data area which is passed to the above two callback functions each time they are called.
lpActualSize	LPAT_UINT	Actual size of the image is returned in the variable referenced by this pointer. Can be NULL.

Return Value:

Returns 0 if successful. Otherwise, returns the number of ImageGear errors that occurred during this function call.

Supported Raster Image Formats:

All pixel formats supported by ImageGear for C and C++.

Actual set of pixel formats supported by this function can be narrower, depending on the implementation of the user-defined callback functions.

Sample:

Load Callback

Example:

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AT_ERRCOUNT nErrcount; // Count of returned errors on stack HIGEAR hIGear; //ImageGear handle AT_BYTE* lpMemoryBlock; // Memory block to save the image to AT_UINT nMaxSize; // Size of the memory block nErrcount = IG_load_file("picture.bmp", &hIGear); if(nErrcount == 0) { // Get a required size of the memory block nErrcount = IG_save_file_size_calc ( hIGear, IG_SAVE_BMP_UNCOMP, &nMaxSize); // Allocate a memory block lpMemoryBlock = (AT_BYTE*)malloc(nMaxSize); // Save image to the memory block in BMP format without compression: nErrcount = IG_save_mem_CB_ex(lpMemoryBlock, 0, nMaxSize, 1, 0, IG_SAVE_BMP_UNCOMP, MyRasterGetEx, MyDIBGetEx, &hIGear, NULL); // Destroy the image IG_image_delete(hIGear); // Some usage of the image in the memory //... free(lpMemoryBlock); }

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AT_ERRCOUNT     nErrcount;            // Count of returned errors on stack
HIGEAR hIGear;                        //ImageGear handle
AT_BYTE* lpMemoryBlock;                // Memory block to save the image to
AT_UINT nMaxSize;                    // Size of the memory block

nErrcount = IG_load_file("picture.bmp", &hIGear);
if(nErrcount == 0)
{
    // Get a required size of the memory block
    nErrcount = IG_save_file_size_calc ( hIGear, IG_SAVE_BMP_UNCOMP, &nMaxSize);
    // Allocate a memory block
    lpMemoryBlock = (AT_BYTE*)malloc(nMaxSize);
    // Save image to the memory block in BMP format without compression:
    nErrcount = IG_save_mem_CB_ex(lpMemoryBlock, 0, nMaxSize, 1, 0, IG_SAVE_BMP_UNCOMP, 
        MyRasterGetEx, MyDIBGetEx, &hIGear, NULL); 
    // Destroy the image
    IG_image_delete(hIGear);
    // Some usage of the image in the memory
    //...
    free(lpMemoryBlock);
}

Remarks:

This function works similarly to IG_save_FD_CB_ex, except that the saving is made to a memory buffer rather than a file.

In order for an ImageGear append page operation to work properly, the memory buffer must point to the very beginning of the existing image, rather than to one of its pages, start of pixel data, or any custom wrapper preceding the image.