WMF stands for Windows Metafile Format. Metafile means that this file contains information that describes or specifies another file. WMF was introduced by Microsoft.
WMF saves space already-built comparing with bitmaps especially when many bitmaps are used repeatedly by different components of the operating system or of an application. The WMF file was created for a 16-bit operating system. For 32-bit operating systems Microsoft developed an enhanced metafile format (EMF). Microsoft's clipboard (CLP) file may contain an EMF file, a WMF file, or a bitmap format file (BMP).
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