IG_fltr_compressionlist_get

This function returns the list of compressions available for saving the specified image to a particular file format.

Declaration:

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AT_ERRCOUNT ACCUAPI IG_fltr_compressionlist_get_ex( const HIGDIBINFO hDIB, AT_MODE nFormatID, LPAT_MODE lpComprList, UINT nCListSize, LPUINT lpnCListCount );

Arguments:

Name	Type	Description
hDIB	const HIGDIBINFO	Handle of DIB info object that contains image parameters. If NULL, then this function returns all possible compressions.
nFormatID	AT_MODE	File format identifier. See enumIGFormats for possible values.
lpComprList	LPAT_MODE	Pointer to the array to return the list of compression constants to. See enumIGCompressions for possible values. Set to NULL if you only need to obtain the number of available compressions.
nCListSize	UINT	Size of the lpCompList array.
lpnCListCount	LPUINT	Pointer to a variable which will receive the actual number of compression constants.

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++.

Sample:

See GUI component source code.

Example:

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AT_ERRCOUNT nErrCount; // Number of errors on stack HIGEAR hIGear; // Handle of image HIGDIBINFO hDIB; // DIB info handle of image UINT nCount, nActual; // Number of compressions LPAT_MODE lpCompList; // List of compressions // Load the image nErrCount = IG_load_file("picture.tif", &hIGear); if( nErrCount==0 ) { nErrCount = IG_image_DIB_info_get(hIGear, &hDIB); // Get compression count nErrCount = IG_fltr_compressionlist_get_ex(hDIB, IG_FORMAT_TIF, NULL, 0, &nCount); // Allocate memory for compressions lpCompList = (LPAT_MODE) malloc(nCount * sizeof(AT_MODE)); // Get list of compressions that can be used when // saving the given image into TIFF format nErrCount = IG_fltr_compressionlist_get_ex(hDIB, IG_FORMAT_TIF, lpCompList, nCount, &nActual); // ... // Delete memory free(lpCompList); // Delete DIB info IG_DIB_info_delete(hDIB); // Delete the image IG_image_delete(hIGear); }

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AT_ERRCOUNT nErrCount;  // Number of errors on stack
HIGEAR hIGear;          // Handle of image
HIGDIBINFO hDIB;        // DIB info handle of image
UINT nCount, nActual;   // Number of compressions
LPAT_MODE lpCompList;   // List of compressions

// Load the image
nErrCount = IG_load_file("picture.tif", &hIGear);
if( nErrCount==0 ) 
{
    nErrCount = IG_image_DIB_info_get(hIGear, &hDIB);
    // Get compression count 
    nErrCount = IG_fltr_compressionlist_get_ex(hDIB, 
        IG_FORMAT_TIF, NULL, 0, &nCount);
    // Allocate memory for compressions
    lpCompList = (LPAT_MODE) malloc(nCount * sizeof(AT_MODE));
    // Get list of compressions that can be used when  
    // saving the given image into TIFF format
    nErrCount = IG_fltr_compressionlist_get_ex(hDIB, 
        IG_FORMAT_TIF, lpCompList, nCount, &nActual);

    // ...

    // Delete memory
    free(lpCompList);
    // Delete DIB info
    IG_DIB_info_delete(hDIB);
    // Delete the image
    IG_image_delete(hIGear);
}