Libra: Q PDF Pages

A PDF reader for Windows 10

Last Updated on May 2018.

This app is available in Windows store. The source code is available at GitHub.

Q PDF Pages is a PDF viewer designed for windows tablets with stylus (e.g. the surface pen). It is not intended to be a powerful PDF application. Instead, it is an app for reading PDF files and taking some simple notes with the stylus.

The key features include:

• View pages vertically or horizontally
• Keep multiple views and easily switch between views
• Take notes with stylus

Motivation

I like the idea of having a pen for a tablet when Microsoft introduce the first generation of Surface Pro. Here, a pen means a real digital pen like surface pen or Apple pencil, not a capacitive stylus similating the touch input. The digital pen is much more precise and pressure sensitive. However, back in 2013, in the Windows App store, I can hardly find PDF viewer satisfies my simple needs: taking notes with the pen while moving the content with my fingers. A app should distinguish between touch inputs and pen inputs. There is one leading app which can do this, however, when I tried it in 2014, its performance was very poor on my old tablet and it crashes a lot. I am not sure if it works better on high-end tablets. Anyway, the app does not work for me (and now it becomes expensive to use). Eventually, I make my own app in 2015. It reads PDFs, and it keeps my notes. I want to keep it simple.

Known Issues

The PDF pages are rendered using the APIs provided by Microsoft (Windows.Data.Pdf namespace). I do noticed some rendering issues:

• Some images, especially some background images will be rendered at a low quality.
• Embedded annotations (e.g. sticky notes inserted by Adobe Acrobat) cannot be displayed.

Unfortunately, I have no intention to purchase commercial PDF APIs. Therefore, these issues will remain for a while.

The App