If you need to work with PDF image format you should know a little more about it. PDF means Portable Document Format ,It is an independent file format used to present documents. Each file contains a complex description of a fixed-layout flat document. It includes the text, fonts, graphics, layout settings and other information needed to display it.

To work with this graphic format on Mac OS you will need special software. For example "WMF Converter Pro" from the "Cristallight Software" company. This is a specialized program for reading and converting WMF / EMF images on Apple Macintosh computers. The program has an intuitive user interface and uses a dark style. You can convert WMF to PDF as vector picture using this software.

Three steps for conversion from WMF to PDF:

• open picture using file menu or just drag&drop it into application window,

• setup other then default output resolution and export folder* (* not necessary),

• and press "PDF" titled violet button in bottom of app screen.

Main Features of "WMF Converter Pro":

• Navigate through WMF and EMF images using navigation keys and keyboard shortcuts,

• View WMF and EMFs at different zoom amounts,

• Convert mac wmf files to vector formats,

• Convert wmf files to most common raster formats with different resolution amounts,

• Batch convert images, or folders with wmf/emf files,

• Multiple WMF and EMF files processing,

• WMF image information display,

• Replace colors feature in vector based WMFs,

• Export images to PDF, EPS, BMP, JPEG, JPEG-2000, PNG, TIFF and other image formats,

• Export WMF and EMFs as mac 'ICNS' files,

• Multiple export buttons,

• Customizable image Preview size, and

• Export folder hierarchy.

PDF history from Wikipedia:

PDF was developed in the early 1990s as a way to share computer documents, including text formatting and inline images. Adobe Systems made the PDF specification available free of charge in 1993. PDF was a proprietary format controlled by Adobe, until it was officially released as an open standard on July 1, 2008, and published by the International Organization for Standardization as ISO 32000-1:2008.In 2014, ISO TC 171 voted to deprecate XFA for ISO.On January 9, 2017, the final draft for ISO 32000-2 was published, thus reaching the approval stage.32000-2 ("Next-generation PDF").

More information how to convert WMF to PDF can be found here: http://www.cristallight.com/WMFConverterPro/