Wednesday, December 16, 2015

Sharpening photos with gimp

I find quite confusing the fact that the most powerful tool for image sharpening is called unsharpen mask. This is so for historical reasons so we need to live with it. The tool options functionality is also a bit confusing. The manual does a good job in explaining it (

Friday, December 11, 2015

Spectre 2015

Watched the latest James bond film yesterday. Not a bad film although it is a bit predictable. It follows the particular pattern of James bond films

Sunday, November 29, 2015

Adding a list of numbers in linux command line

Lets say, that you want to see how much space a specific set of files take in the disk. You need to add their sizes. How do you do that using command line?
Easy: ls -l *052015|awk '{s+=$5}END { print s}'

This will sum the size of backups made in May 2015 and return the total. Neat eh?

Sunday, October 4, 2015


The last book of the Drizzt series (The forgotten realms). Coming after the Iron dwarf it continues the story of the companion of the halls, trying to take Gauntlgrym back. It is a nice, easy reading, not too complicated, with a few nice twists here and there.

Tuesday, September 1, 2015

Dehazing a photo

A nice tutorial can be found here

Sunday, August 23, 2015

The Iron Dwarf

Finished the Iron Dwarf of Drizzt series. One of the better books of the series, it is quite enjoyable :)

Wednesday, August 12, 2015

Sony a700 custom settings

A700 high iso settings
sta suggested

the following custom settings: 
base mode 'standard', saturation +1, sharpness +2, brightness -2, 
zone matching -1; DR+; high ISO NR 'high'.
This option of standard can be found the same way as deep option

And setting for normal light photos
Base mode deep 0 contrast +1 saturation +1 sharpness 0 lighting +1 zone

Sunday, July 19, 2015

Photography books

I have discovered a free downloadable book for photography in greek. So far it seems quite nice and accurate. You can find it here

Thursday, June 25, 2015

Finished digital photography faqz by Jeff wignall

Not a bad book at all. It is written in a question and answer style and the answers come directly to the point. A good  read. Amazon url:

Sunday, May 24, 2015

Alternative google drive client

It seems that google has deprecated the version of its API, that has been used by grive. On the other hand there is an alternative called drive and can be found here:

Wednesday, May 20, 2015

Reading cryptonomicon

It is a weird but interesting book. Quite technical with technology and cryptography references. It is consisted by three storylines that are running in parallel. Two storylines are placed in the 2nd world war period and the third is placed in the modern world. I have not been to the point where the storylines converge yet but it not too far away. It is a biggish book of more than 1000 pages in my nook reader

Monday, April 13, 2015

The mythical man month

Finished this book. It is a book about software development management and is considered by many as a classic. It is definitely an interesting book, somewhat out of date but  most of it is still current. Another interesting fact is that it provides some insight to the way software management and development was done in 1970s. Definitely worth the time.

Saturday, April 11, 2015

Edinburgh science festival

This year i attended three event of the Edinburgh science festival. The titles are:

  •  Sugar on the dock
  •  The living brain
  •  The science of in the Game of Thrones

All of them were in Summerhall Main Hall, and were quite well organised. They were sponsored and supported by various universities, and scientific, like the societies university of Edinburgh and the Physiological society.

The Sugar on the dock, was an interesting session, that described the various types of sugar in existence, their use today, the effect on our health and the suggested daily intake of sugar by WHO (thats 10%). One of the facts that i didn't know about is that diabetes is linked to obesity with a different weight threshold for each individual.

The Living  Brain, discussed the effect of aging in the cognitive processes. The tl;dr is that it deteriorates, but the starting point depends on the person. The smarter you are, your cognitive processes from a higher point, meaning that the overall decline will take longer. Which is good.

The science in the Game of Thrones, was the most popular of the three events, and also the most impressive, since it revisited various scenes of the series, from a scientific point of view. We discussed if wildfire is possible (with live demo of setting fire to a miniature fleet), if dragon fire is possible (no demo here), if a skull can be crushed with bare hands (demo with a sheep skull) and more.

All in all it was fun, and i learned a couple of things it didn't know :)

Thursday, April 9, 2015

Fullmetal alchemist

Finished this series of anime. Not bad at all,  quite interesting series with lots of action and we'll made graphics

Saturday, March 28, 2015

Simple rest with scala

If you are interested in writing simple rest enabled Web apps and are looking for a sinatra like framework in the java world, scalatra may be the answer.
It leverages the rich feature set of scala and the rich community of java. It uses jetty by default making it easy to use without complicated setup but I guess that the end product could be used in a traditional container server quite easily

Sunday, March 15, 2015

Programming scala

Finished this book (almost). Oh boy this book goes deep. Deeper than I would like for an introductory book. That is good and bad at the same time. It is an investment. It also presents best practices in a number of cases and provides elegant solutions in a number of problems.
So I will say that it is a good book to read more than once.

Monday, March 2, 2015


Finished reading this book by top gear presenter Jeremy Clarkson.
This is a book about his experiences while filming the Motorworld episodes around the world.
It makes for a nice relaxed reading especially if you are a motorsports fan. It is not heavy on technical details and Clarkson's humour makes it really easy to read.

Sunday, February 22, 2015

Salt in masterless mode

It seems that salt supports a standalone, isolated "masterless" execution mode. The only thing needed is salt-minion and the state/pillar files. For more details check this out. No extra services are needed.

Friday, January 30, 2015

Mpv and mps-youtube

After the suggestion of friends, i have tried to use the command line media mplayer mpv yestreday and the mps-youtube, youtube player today.
As promised, both are command line tools, that are both powerful and simple at the same time.
mpv exists as a command on its own through the ubuntu repos and mps-youtube is a python tool installable through pip.
In order to use it you need to call the command mpsyt

Tuesday, January 20, 2015

View git tag creation date

The git tag creation date should be easy to retrieve, right?
Wrong. The command to do that is not very easy to remember.
Here is how you can do it:

git log --tags --simplify-by-decoration --pretty="format:%ai %d"

Sunday, January 18, 2015

A few words about swap in linux

Just because swap is allocated, doesn't mean it's being 'used'. Whilst programs like system monitor and top will show some of your swap space being allocated that doesn't mean that the system is actively swapping in/out.
To find out if anything is swapping in/out you can use the vmstat command. Leave it running a few seconds to settle down and watch the si (swapin) and so (swapout) columns. If nothing is happening then there is no reason to be concerned.

Use the command vmstat 1 and watch the output.

Some people suggest that in order to clean the swap used on the machine you can do a swapoff -a && swapon -a. That will do the trick, but i am not sure what will happen if the system needs the swap while it is off. It possible that just rebooting is a better option.

Saturday, January 17, 2015

Changing the default boot option in Grub2

Grub2 is using a new weird configuration format. If you want to change the default boot option you can find instructions here.

In short do a  fgrep menuentry /boot/grub/grub.cfg

find the menu entry you are interested in, edit /etc/default/grub  and copy the name of the entry in the

entry. Save the file and do a

sudo update-grub

Thats it

Thursday, January 8, 2015

Tmux cheat sheet

tmux is a terminal multiplexer. It is newer than the venerable screen and is supposed to have a richer feature set. Here is a cheatsheet

Sunday, January 4, 2015

Converting a typical netbeans project to maven.

For some weird reason, i think that converting my netbeans project from ant to maven is a good idea, so i will give it a go following the directions at this blog post and this