You can download the source code of this example (VBScript) here: pdfdocscout_using_png.zip 
You can download the source code of this example (VB.NET) here: pdfdocscout_loading_png_images_vb_net.zip 

This example shows how to convert PNG image into PDF document using PDFDoc Scout library

Generated PDF document will look like this:

Code to convert PNG image to PDF using PDFDoc Scout lib:

' this example uses PDFDoc Scout Image Addon to load PNG into PDF document

Set PDFDoc = CreateObject("PDFDocScout.PDFDocument")
Set ImageLdr = CreateObject ("PDFDocScoutImgAddon.ImageLoader")

PDFDoc.InitLibrary "demo", "demo"
PDFDoc.OutputFilename = "png_sample.pdf"
PDFDoc.AutoOpenGeneratedPDF = true

PDFDoc.BeginDocument

ImageLdr.ConnectToPDFLibrary (PDFDoc)
Image = ImageLdr.AddImageFromFileNameEx ("sample.png", 1) ' 1 = ictJPEG type image compression, we store image as JPEG inside PDF

ImageLdr.DisconnectFromPDFLibrary

PDFDoc.Page.PlaceImage Image, 10,10 ' place image to current page at (10,10)

PDFDoc.EndDocument ' close PDF document generation

' disconnect from library
Set PDFDoc = Nothing

You can download the source code of this example (VBScript) here: pdfdocscout_using_png.zip 
You can download the source code of this example (VB.NET) here: pdfdocscout_loading_png_images_vb_net.zip