Adjust contrast and brightness of a PDF


In case you want to adjust brightness and contrast of a PDF file on the Mac (or Linux) you can use ImageMagick. Here is what I used:

convert -brightness-contrast 10,50  -compress lzw  \
        -density 500 -colorspace Gray input.pdf output.pdf

the -brightness-contrast 10,50 controls the brightness and contrast (they can both take values from -100 to +100), Density controls the resolution and -colorspace controls the color output. In this case, its Gray. lzw is a lossless compression method.


Dropbox won’t start due to permissions


This is a solution to the problem of Dropbox for the “Couldn’t start Dropbox
This is usually because of a permissions error. Errors can also be caused by your home folder being stored on a network share.” message. […] Continue Reading…


Passing Kerberos TGT (ticket-granting ticket) to remote hosts with ssh


Kerberos uses tickets to grant access to resources on a Kerberos-enabled computer. If you want to login (via SSH) to a remote host and you don’t want to re-execute the kinit command after you login, you can just forward your ticket with your ssh client. Two steps are needed to do this – given that your Kerberos client is configured:

Create a Kerberos forwardable ticket to your machine
and, forward your ticket while logging in to the remote machine.

In order to create a forwardable ticket execute kinit with the “-f” argument. […] Continue Reading…


Google’s support for RDFa and Microformats


Google has announced that their search engine is going to support enhanced searching in web pages, by using RDFa and Microformats embedded in XHTML. Google states that the extra (structured) data will be used in order to get results for Product Reviews (e.g. CNET Reviews), Products (e.g. Amazon product pages), People (e.g. LinkedIn profiles) and any other types of resources will be made public through the W3C is pretty happy about that.

The news are good for three reasons:

Google supports an Open Standard (RDFa by W3C) and also an […] Continue Reading…


Merging multiple Lucene indexes


Apache Lucene LogoThis is the code that I use to merge multiple Lucene indexes into one. There are many reasons to merge multiple indexes into one like:

    • Speed
    • Ease of management
    • Space – the size of the merged index is less than the sum of non-merged indexes

[…] Continue Reading…