IG_info_get

This function obtains information about the image located in a memory buffer. This is an obsolete function, see remarks.

Declaration:

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AT_ERRCOUNT ACCUAPI IG_info_get_mem( LPVOID lpImage, AT_UINT nImageSize, UINT nPage, LPAT_MODE lpFileType, LPAT_MODE lpCompression, LPAT_DIB lpDIB );

Arguments:

Name	Type	Description
lpImage	LPVOID	Pointer to memory location of an image file that is currently in memory.
nImageSize	AT_UINT	Size of image in memory.
nPage	UINT	Page number for which the info is obtained. Note that page numbers begin at 1, not 0. Set nPage to 1 if this is not a multi-page memory file.
lpFileType	LPAT_MODE	Pointer to an AT_MODE variable in which the file type will be returned. See enumIGFormats for possible values.
lpCompression	LPAT_MODE	Pointer to an AT_MODE variable in which compression type will be returned. See enumIGCompressions for possible values.
lpDIB	LPAT_DIB	Pointer to an AT_DIB structure to which other file information such as width, height, and Bits Per Pixel will be returned.

Return Value:

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

Supported Raster Image Formats:

If lpDIB is not NULL, then

Indexed RGB - 1, 4, 8 bpp;
Grayscale - 9...16 bpp;
RGB - 24 bpp;
CMYK - 32 bpp.

otherwise, all pixel formats supported by ImageGear for C and C++.

Sample:

None

Example:

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char* lpBuffer; // Memory buffer with the image AT_UINT nBufferSize; // Size of the memory buffer AT_MODE nFileType; // Will receive an IG_FORMAT_ constant AT_MODE nCompression; // Will receive an IG_COMPRESSION_ constant AT_DIB atDIB; AT_ERRCOUNT nErrcount; // Returned count of errors // Open a file and get its size FILE* fp = NULL; fopen_s(&fp, "picture.bmp", "rb"); if(fp != NULL) { fseek(fp, 0, SEEK_END); nBufferSize = (AT_UINT)ftell(fp); fseek(fp, 0, SEEK_SET); // Allocate memory and read the image into the memory buffer lpBuffer = (char*)malloc(nBufferSize); fread(lpBuffer, 1, nBufferSize, fp); // File is no longer needed - close it fclose(fp); // Get image info nErrcount = IG_info_get_mem(lpBuffer, nBufferSize, 1, &nFileType, &nCompression, &atDIB); fclose(fp); // ... // Delete memory buffer free(lpBuffer); }

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char* lpBuffer;            // Memory buffer with the image
AT_UINT nBufferSize;    // Size of the memory buffer
AT_MODE nFileType;        // Will receive an IG_FORMAT_ constant
AT_MODE nCompression;    // Will receive an IG_COMPRESSION_ constant
AT_DIB atDIB;
AT_ERRCOUNT nErrcount;        // Returned count of errors

// Open a file and get its size
FILE* fp = NULL;
fopen_s(&fp, "picture.bmp", "rb");
if(fp != NULL)
{
    fseek(fp, 0, SEEK_END);
    nBufferSize = (AT_UINT)ftell(fp);
    fseek(fp, 0, SEEK_SET);
    // Allocate memory and read the image into the memory buffer
    lpBuffer = (char*)malloc(nBufferSize);
    fread(lpBuffer, 1, nBufferSize, fp);
    // File is no longer needed - close it
    fclose(fp);
    // Get image info
    nErrcount = IG_info_get_mem(lpBuffer, nBufferSize, 1, &nFileType, &nCompression, &atDIB);
    fclose(fp);

    // ...
    // Delete memory buffer
    free(lpBuffer);
}

Remarks:

This function is only kept for backward compatibility reasons. Please use IG_info_get_mem_ex instead.

Any of the output parameters such as lpFileType, lpCompression or lpDIB can be NULL, if the corresponding info is not required.