Generate Thumbnails From a PDF

I have a PDF files with 180+ pages.  I want to generate thumbnails 200×250 in JPG format.

PDFView4Net: It takes a total of ~52 seconds.

Looking for an alternative solution, I come across a solution involving ImageMagick+GhostSciprt.  Using the command “convert”, it takes only ~15 seconds to generate all the thumbnail images.  However, the image quality seems to suffer a little.  The default dpi is 72 for ImageMagick vs 96 for PDFView4Net.

The windows version of ImageMagick has a bug.  If you have a multiple pages PDF, it may convert only the first page.

The solution is “Edit delegates.xml and change pngalpha to pnmraw.”  It works for me.


Lenovo Yoga Hotkey vs. Function Keys

If you frequently use function keys, F1-F12, then you probably want to disable the Hotkey mode.  That way, you can press “F1” key, without pressing “Fn” key.

  1. Shutdown,
  2. Press Novo button.  See the diagram below to locate Novo button.
  3. Select BIOS Setup
  4. Switch to 2nd page
  5. Disable Hotkey Mode.
  6. Press “Fn”+F10 in order to save and exit the BIOS.
  7. After that, life is a bliss.


iText for .Net

Book Review: iText in Action Second Edition

My initial impression: I find the book useful in understand how to use iText.  For example, there are at least 4 different ways to copy a page from PDF: PdfWriter, PdfStamper, PdfCopy, PdfSmartCopy.


iTextSharp DLL

I downloaded and found 3 DLLs.  At first, I was at a loss of what they were meant for.  I hope the following info would help others decide when to use them: 

  • itextsharp.dll – this is the core dll.  If you use iText, you need it.
  • itextsharp.pdfa.dll – this is for PDFA, a variant of PDF that is specialized for long term archiving.  For example, font embedding is used over font linking.
  • itextsharp.xtra.dll – this is needed for hyphenation or asian languages.  Hyphenation rules determine whether to split a long word at the end of a line (e.g. elephant vs e-lephant).


iText is not designed to render PDF files.  For example, you cannot use iText to generate thumbnail images from each page within a PDF.

Dropbox Limitation on Sharing Folders

Sharing  Parent and Child Folders with Different Collaborators

For example, you might have a folder structure like this:

  • AllData
    • ClientAData
    • ClientBData

Now, you can share ClientAData with Client A and share ClientBData with client B.   But if you do that, you can no longer share the parent folder AllData with another operator or administrator.

If you try to do that, you can an error “You can’t share a folder that contains a shared folder.”

Until the sharing options improve, it is hard to utilize Dropbox as a way to exchange enterprise data.

Windows 8 is Made for Lenovo Yoga 13 – Part 1

After 3+ years of suffering with a HP laptop, I finally got my hand on the new Lenovo Yoga 13. 

It took a lot to overcome the frugal side of me and invest ~$1,700 of my personal money into a laptop.  I know I know… it is nothing in the Apple world. 

Now, I already have 2 iPads at home and they are great for entertainments.  But they are just not meant for serious work.

I want to interrupt this program by thanking Microsoft for gifting me a Samsung Slate Series 7, valued at taxable $1,000.  I was tempted to keep it, but I sold it as it could only have a max of 4GB of memory.

The story of my yawning for a powerful tablet to be continued …