Combining PNG files into one multi-page PDF document means a lot of manual edits and adjustments and need in a few programs. Far simpler approach is offered in Total Image Converter. You just take PNG sources from your memory folders, set the formatting for future PDF file, and the program does the rest, outputting a PDF document that contains all original images.
The program has a built-in navigation tool for easy search for source files. The list of files from selected folder is displayed to the right of folder tree. There you need to check off required PNG source files. As it is a batch converter, any number of files is acceptable in one batch. After this press PDF at the top format bar. In appeared wizard there is a tab called "Select destination". Here are a few options to choose from:
Every image to separate file
Combine images into one document
Separate files by folders
Separate by common name part
In order to combine all PNG images into one PDF document, you should check off the second option. The first one will convert images separately, the third one combines images from one subfolder into one PDF file. The last one combines images that have the same name part together.
You will see a range of other settings that will help to gain exactly the formatting you need. After all preparations are finished, press Start!, and in a few seconds the program will give you converted PDF file.
Alternatively to graphic interface there is a command line mode. You can send conversion commands in cmd dialogue window. It is very simple: you need to write a command that includes necessary parameters. It will be like this:
Every image to separate file