PPT to PNG with transparent background

It can't be done, either manually or progamatically. This is because the color behind every slide master is white. If you set your background to 100% transparent, it will print as white.

The best you could do is design your slide with all the stuff you want, group everything you want to appear in the transparent image and then right-click/save as picture/.PNG (or you could do that with a macro as well). In this way you would retain transparency.

Here's an example of how to export all slides' shapes to seperate PNG files. Note:

1. This does not get any background shapes on the Slide Master.
2. Resulting PNGs will not be the same size as each other, depending on where the shapes are located on each slide.

3. This uses a depreciated function, namely Shape.Export. This means that while the function is still available up to PowerPoint 2010, it may be removed from PowerPoint VBA later.

   Sub PrintShapesToPng()
       Dim ap As Presentation: Set ap = ActivePresentation
       Dim sl As slide
       Dim shGroup As ShapeRange
       For Each sl In ap.Slides
           ActiveWindow.View.GotoSlide (sl.SlideIndex)
           sl.Shapes.SelectAll
           Set shGroup = ActiveWindow.Selection.ShapeRange
           shGroup.Export ap.Path & "\Slide" & sl.SlideIndex & ".png", _
                               ppShapeFormatPNG, , , ppRelativeToSlide
       Next
   End Sub
   

You can select the shapes within a slide (Word Art also) and right click on the selection and choose "Save As Picture". It will save as a transparent PNG.

One workaround that I have done is:

• Ctrl + a to select everything in the slide
• Ctrl + c to copy it
• open GIMP (probably works in Photoshop or other software)
• make a new image with a transparent background
• Ctrl + v to paste all the vectors/text into the image
• Export the image to a PNG or whatever format

It looks pretty much exactly the same as in Powerpoint, and the vectors/text are very clean with their transparency edges.