Browsing the 2009 December archive
Cleaning dust on photos: or “In Gimp We Trust!”
14 Comments | Filed under Linux-Planet devel english mandriva tutorialA few weeks ago I finally realized my old wish: I bought a real camera for me: a Nikon D40 – which is, according to many, many people, is the best DSLR out there. At least for non-professionals.
With just a few pictures it was already possible to note the difference – I could not ever EVER got close to those pictures with all my previous cameras (like Nokia N95 and Sony CyberShot W90):
However, after a few days with my new camera, I found out that it came with some dust on its sensor. Not much, but clearly visible on pictures with uniform colors (like sky or white wall). For example, it is possible to see the dust spot on the left half of the following picture – if you zoom in, you’ll clearly see that there is some dark spot covering part of a cloud and appearing in the sky:
One could say ‘Ahh, but that is just a small tiny spot.. nobody will notice it’. But… I do notice it, and I don’t like it. So I started looking for solutions for this issue.
In first place, I tried cleaning the sensor using a air blower (without luck). The dust spot moved a bit with the air flow (a few microns) and landed to its new place (permanently, I afraid). The next step was to ask the official Nikon support in Brazil, which is located in São Paulo city, about 250km from where I live. Their answer was is that the sensor cleaning should cost around R$ 100 (about 60 US$) + shipping. Quite expensive in my opinion.
So the next step was to start thinking like a computer geek. The photo is digital, so it is nothing more than a bunch of bits
. So there SHOULD be some software or at least algorithm suitable for cleaning this all. After a quick research, I found that there is the Nikon Capture NX software which removes the dust pretty well. However, it is
- commercial
- expensive
- orders you to take photos in RAW only. I like RAW, but… the memory card is not infinite.
So another option was to clean the dust in gimp. Manually… and it is needless to say that this approach is.. well.. boring, time-consuming and pretty much futile.
However, when all the hope was, apparently, lost, the Great Google Gods sent me a wonderful link to the Resynthesizer plugin – which is AMAZINGLY EFFICIENT in solving the dust issues.
So, dear readers, without other words, I’ll show you the few needed steps to fix the dust on your photos:
Install resynthesizer plugin. On Mandriva systems, you can cheat and run a magic urpmi gimp2-resynthesizer command which will do the trick. On other systems, go to the resynthesizer web site, download, compile and install the plugin. it is trivial, so I won’t go into additional details here.
Grab your dust-damaged image and open it in gimp. As you can see, there is a horrible dust on the left part of the otherwise-blue sky:
- Select a region around the dust to remove:
- Press CTRL-X to remove the selected area:
- Now, select a bit larger region around the white spot:
- Go to Filters->Map->Resynthesize and run the Resynthesize filter:
- Wait, wait, and…:
- That’s it!:
Of course, it all could be done manually in gimp. However, the Resynthesizer plugin just makes it easier and better.
So what is the result? A bit more magic + some Hugin hacking and…:
Yes, that’s right. Every image on panorama had a dust spot, which I cleared up with Resynthesizer. So next time you encounter some dust on your photo, remember that there is a GREAT open-source plugin for gimp out there to help!
Enjoy, and have a Happy New Year!
New year, new car.. a tribute to Renault Megane, and a Merry Christmas message
2 Comments | Filed under english mandrivaAnother year is coming to an end, and, as everything in life, time comes to retire an old car and switch to a new one. And this time has come for me as well – after 4 years with my precioussss Renault Megane, I switched to a new car. So now I feel that the 4-years experience was quite enough to get a good opinion about the Megane.
Well, first of all, this was definitely the best car I ever had or driven. It is extremely stable, fast, easy to control and comfortable. Yet by some reason, it seems to be quite an outcast here in Brazil, and it leads to problems related to the repair parts and their prices.
During those 4 years I never ever had any serious problems with this car, and I can recall at least 5 times when it really saved my life when any other car would have been completely destroyed or at least seriously damaged. The car’s stability is phenomenal, and its easy of control at any speed and in all situations are remarkable.
So this post is sort of a tribute to my old Renault Megane. It was amazing to have you, and thanks for the ride!
And, as the year is coming an end, I’d also wish a Merry Christmas and a happy 2010 to everyone who read, commented or just passed by and looked at this blog! See ya!


























