L_LoadBitmapMemory

Summary

Loads an image file from memory into a bitmap. The file in memory can be in any supported image file format and bits per pixel, whether compressed or uncompressed.

Syntax

L_LTFIL_API L_INT L_LoadBitmapMemory(pBuffer, pBitmap, uStructSize, nBitsPerPixel, nOrder, nBufferSize, pLoadOptions, pFileInfo)

Parameters

L_UCHAR * pBuffer

Pointer to the file in memory to be loaded.

pBITMAPHANDLE pBitmap

Pointer to the bitmap handle referencing the target bitmap.

L_UINT uStructSize

Size in bytes, of the structure pointed to by pBitmap, for versioning. Use sizeof(BITMAPHANDLE).

L_INT nBitsPerPixel

Resulting bitmap pixel depth. The following are valid values:

L_INT nOrder

Color order for 16-, 24-, 32-, 48-, 64-bit bitmaps. If the resultant bitmap is less than 16 bits per pixel, this will have no effect since palletized images have no order. The following are valid values:

L_SSIZE_T nBufferSize

Size of the file in memory (in bytes).

pLOADFILEOPTION pLoadOptions

Pointer to optional extended load options. Pass NULL to use the default load options.

pFILEINFO pFileInfo

Pointer to a FILEINFO structure. This structure may contain file information used in loading an image, or it may be updated with information about the file being loaded.

If nothing is known about the file, pass NULL for this parameter, or declare a variable of type FILEINFO and set the FILEINFO.Flags to 0, then pass the address of the FILEINFO structure in this parameter. In this case, if the address of a FILEINFO structure is passed, the FILEINFO structure will be updated with the results of L_FileInfo.

If only the file type is known, set pFileInfo.Format to the file type and set pFileInfo.Flags to FILEINFO_FORMATVALID. This can also be done if L_FileInfo has been called previously, but values that affect the size of the image loaded have been changed (for example, by calling L_SetPCDResolution or L_SetWMFResolution). In this case the FILEINFO structure pointed to by pFileInfo will be updated with the results of L_FileInfo.

Some file formats do not contain a well-defined file signature. This is especially true for document file formats (TXT, PST, etc). LEADTOOLS can still detect the file format using the filename extension (ex. ".PST"). However, when loading files from memory the filename extension is not available. To provide this function with a filename extension, set pFileInfo.Name to the image file's name with extension and pFileInfo.Flags to FILEINFO_NAMEVALID when loading from memory.

If L_FileInfo has been called prior to calling this function, and no changes have been made to the contents of the structure filled by L_FileInfo, then the address of the filled FILEINFO structure can be passed for this parameter. In this case, the FILEINFO.Flags member should be set to FILEINFO_INFOVALID. The L_FileInfo function will set the FILEINFO.Flags to FILEINFO_INFOVALID. In this case the load will be faster since this function does not have to query the file filters for the file type.

Note: Local variables are not initialized (since they are placed on the stack). So if you have a FILEINFO structure as a local variable, the value of its Flags parameter is undefined, possibly having FILEINFO_INFOVALID or FILEINFO_FORMATVALID set. That is why it is important to initialize FILEINFO.Flags before passing the address of the FILEINFO structure to the function.

Returns

Comments

Support for 12- and 16-bit grayscale images is only available in Document and Medical Imaging toolkits.

For supported formats, refer to Files To Be Included With Your Application.

Before calling this function, you may need to get or set file information, such as the page number of a multipage file. Refer to Getting and Setting File Information.

The function will initialize the bitmap handle and allocate the storage necessary to hold the image. If the bits per pixel of the file is larger than 8 bits, the image data will be loaded in the same color order as the one passed to the function in nOrder.

Since the function allocates storage to hold the image, it is up to you to free this storage by calling L_FreeBitmap.

This function cannot be used in combination with L_RedirectIO.

Notes:

• More options are available in the LOADFILEOPTION structure.

• Redirected IO is not supported for some file formats. For more information, refer to File Formats for Which Redirected IO is Not Supported.

• You should never pass an uninitialized FILEINFO structure to this function.

Required DLLs and Libraries

• LTFIL
• File format DLLs
• For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Win32, x64, Linux.

See Also

Functions

• L_LoadMemory
• L_LoadBitmapMemory
• L_LoadMemory
• L_SetWMFResolution
• L_SetLoadInfoCallback
• L_SetLoadResolution
• L_SetPCDResolution
• For Vector files:
• L_2DGetViewMode
• L_2DGetViewPort
• L_2DSetViewMode
• L_2DSetViewPort
• L_GetLoadStatus

Topics

• Raster Image Functions: Loading Files
• Raster Image Functions: Redirecting Input and Output
• Raster Image Functions: Input and Output
• Loading and Saving Images
• Using a PanWindow
• For a list of functions that utilize the LOADFILEOPTION or SAVEFILEOPTION structures, refer to the Usage section of their documentation.

Example

For an example, refer to L_SaveBitmapMemory.
For complete sample code, refer to the MEMORY example.