overlay one pdf or ps file on top of another

You can do this with pdf files using the command line tool pdftk using the stamp or background option. e.g. $ pdftk file1.pdf background file2.pdf output combinedfile.pdf This will only work with a one-page background file. If you have multiple pages, you can use the multibackground command instead.

Why is one of these two itext 7 signed and validated document is not valid with Adobe DC reader?

This is not an Adobe bug, it’s a feature. (And an iText bug) When Adobe performs the cryptographic validation, it will also perform additional checks to see if a signature was attacked or not. It analyses several suspects and if that analysis turns out negative, Adobe will show you an error message. This is Adobe … Read more

Data encoding when submitting a PDF form using AcroForm technology

I’ve just found the answer to my main question myself. I didn’t find anything in ISO-32000-1 or the ISO-32000-2 draft, but studying the Acrobat JavaScript reference, I found the cCharset parameter that is available for the submitForm() method. That parameter defines: The encoding for the values submitted. String values are utf-8, utf-16, Shift-JIS, BigFive, GBK, … Read more

How to open pdf file in Windows Phone 8?

You have to use the LaunchFileAsync method of Launcher class. Example: // Access the file. StorageFile pdfFile = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFileAsync(“file.pdf”); // Launch the pdf file. Windows.System.Launcher.LaunchFileAsync(pdfFile); You will find more info here: Auto-launching apps using file and URI associations for Windows Phone 8