I use LaTeX + Beamer to make presentations, but I’m often asked for PowerPoint versions of the slides. My talks are typically image-heavy, and sharing the PNG files embedded in the PDF is usually sufficient. Sometimes, though, someone really needs a PPT or PPTX file.
The (sort of) solution
First, I use the ImageMagick’s
convert function to convert the PDF presentation into individual PNG files. There are two key considerations here: 1) bitmapping the PDF file sufficiently high density (using the
-density option) and outputting PNG files with sufficiently small size (using the
-resize option). When you use
convert to convert a multi-page PDF to PNG, it automatically appends page numbers to the PNG output. Here’s the command:
convert -density 600x600 -resize 1024x768 -quality 90 presentation.pdf presentation.png
This generates PNG files named “presentation-1.png”, “presentation-2.png”, … The quality parameter is adjustible. In the line above ‘9’ means high quality and ‘0’ means no filtering. See the ImageMagick convert options page for details on this option. Note that the interpretation of the
-quality parameter is format-dependent, with the meaning of ’90’ differing among output formats. If the PNG files are too large,
-resize 800x600 works too, but on a high-resolution projector these will appear notably blurry and/or pixelated.
The next step is to use PowerPoint’s quite nice photo album inserter to add the directory containing the PNG files to an empty PPT file.
I call this a “sort-of” conversion because, as a bitmap-based approach, it does not preserved editable text and vector graphics.