KAЯTHIK's Blog

Welcome to my world…

Technical Error July 29, 2009

Filed under: Computer — KARTHIK @ 12:38 pm

Here is my new blog..

http://www.technicalerror.net/blog

I bought a top level domain this time. It is a self hosted wordpress blog.

I need to do a lot of work to make it live..

I wanted to mainly post tutorials there and this is my personal blog.

comments to improve the new site are welcome.

 

பொன்னியின் செல்வன் July 12, 2009

பொன்னியின் செல்வன்

நான் மிகுந்த ஆர்வத்துடன் படித்த புத்தகம். அமரர் கல்கி க்ரிஷ்ணமூர்த்யின் படைப்பு.

1950 களில் இந்த கதை கல்கி வார இதழில் மூன்றரை ஆண்டு காலம் வெளிவந்தது. [கண்டிப்பாக எனக்கு அவ்வளவு பொறுமை இல்லை]. இந்த கதை, படித்தவர்கள் மனதில் இன்னும் பசுமையாய் உள்ளது.

தற்பொழுது இந்த கதை புத்தகமாக அச்சிடப்பட்டு விற்கப்படுகிறது. ஐந்து அல்லது ஆறு பாகங்களாக பிரிக்கப்பட்டு உள்ளது. விலை மிக குறைவு.

கண்டிப்பாக நான் கதையை சொல்ல போவது இல்லை. நீங்களே படித்து அதன் சுவையை அனுபவித்துக்கொள்ளுங்கள்.

துணுக்குகள்:

– கதை நடப்பது இன்றைய தேதியிலிருந்து சுமார் ஆயிரம் ஆண்டுகளுக்கு முன்னால்.

– கதையின் நாயகன் ‘வல்லவரையன் வந்தியதேவன்’. குறும்பு, வீரம், அழகு, அறிவு அனைத்தும் நிறைந்தவன். ‘இராஜ இராஜ சோழர்’இன் நண்பன்.

– ஆசிரியர் சோழ நாட்டின் வளத்தை பற்றி கூறும் பொழுது அவ்வளவு அழகாக வர்ணிக்கிறார். அப்போது நம் தமிழ்நாடு எவ்வளவு அழகாக இருந்திருக்கும் என்று எண்ணி பார்க்க தோன்றுகிறது.

– ஒவ்வொரு அத்தியாயத்தின் முடிவிலும் அடுத்து என்ன நடக்குமோ என்ற பரபரப்பு ஏற்படுகிறது. அப்போது ஆசிரியரின் திறமையை பற்றி பாராட்டாமல் இருக்க முடியவில்லை.

– வந்தியதேவன் மற்றும் குந்தவை சந்திக்கும் பக்கங்களை பலமுறை படித்தாலும் சுவை குறையாது.

–கதையில் வரும் ஒவ்வொரு பாத்திரமும் நம் மனதில் பதிகிறது.

மேலும் தெரிந்துகொள்ள….

http://en.wikipedia.org/wiki/Ponniyin_Selvan
http://www.tamilnation.org/hundredtamils/kalki.htm
http://www.ponniyinselvan.in/

 

How to create HDR June 4, 2009

Filed under: Photography — KARTHIK @ 6:09 am
Tags: , , , ,

How to create ‘High Dynamic Range’ images:

What is HDR ?

HDR means ‘High Dynamic Range’. Using these technique you can get excellent details in both highlights and shadows. You will be impressed by the artistic effect it creates.

You can get impressive results like this.

What do you need ?

1. Digital SLR camera, [or a camera which supports taking pictures in RAW format]
2. Tripod,
3. HDR software – photomatix.

You can also use Photoshop to create HDR. But photomatix is excellent software which gives you some more controls which is not there in photosohp.

You can also create HDR from jpeg image. But since jpeg is a compressed format, you will lose all details. The RAW file contains all details which we are looking for.

Taking Pictures for making a HDR

1. First set your camera in "Manual mode". Because the shutter speed or aperture should not change since we need the same depth of field in all photos.

2. Take a picture of your subject by setting aperture and shutter speed manually.

3. Then take more pictures with +2 EV and -2 EV. Now you have three pictures with +2,0,-2 EV. You can also take five pictures with +2,+1,0,-1,-2 EV. It is up to you. The time taken for combining 5 photos is larger than combining 3 photos.

4. Next we will see how to generate a HDR image.

Using a single RAW file to create HDR

Often we don’t get chance to take three or more pictures. You can use a single RAW file to 3 or 5 multiple exposure pictures. The main advantage to this is that you can produce a HDR shot with moving subjects such as people or cars. The disadvantage is that if you use an image with very dark shadows and you’re trying to boost the exposure, the result will be quite noisy.

Create 16-bit TIFF from RAW file

1. If you have 3 RAW files open in photoshop and save them as TIFF files.

2. If you have a single RAW file open in photoshop and adjust the Exposure values to +2,-2 etc., and save them separately.

Note: If you are using some other RAW editor, save the image as a 16bit TIFF without any metadata such as EXIF info. This is the important part. If you save it with EXIF info you will find that Photomatix relies on that info to produce the HDR shot. The problem with this is that the shutter speed and aperture values will be the same across the 3 images and Photomatix won’t know which image is -2, 0 and +2. Set the exposure level to 0, save that and then set it to +2 and save that image.

3. Now you will have 3 files. The size of each tiff file will be very large around 50 MB for a 10MP photo. Don’t worry.

Using a JPEG file to create HDR

All we need is 3 images with multiple EV values. Open photosohop, then load the jpeg image.

Add the exposure adjustment layer and set +2, 0 , -2 values. Save each file separately as 16 bit tiff.

Choose File –> Save AS –> and choose TIFF file type. [leave the default options as it is]

Generating a HDR image

Open the 3 images into Photomatix. From the menu select ‘Generate HDR’. Photomatix will ask you if you want to use the 3 opened images or load in some. Make sure it has “Use opened images” selected and click ok. Now Photomatix will confirm the exposures for each image. Many times it will get it right, but just in case make sure that each image has the correct exposure settings. Click ok, then check that “use standard response curve” is selected. If you are using 3 images taken at the scene tick the “Align LDR images before generating HDR image” option just so that Photomatix aligns the images for you. Click ok.

Be patient. Have a cup of coffee. It will take some time :)

Now you will be little disappointed with the outcome. Don’t worry because the magical thing is yet to happen.

Tone Mapping

This is the magic part. Using the Tone Mapping feature in Photomatix will convert your HDR image into something usable. Goto the HDR menu and select Tone Mapping.

You can see different options like this. Play with the sliders to get a sweet spot.

Luminosity
Strength
Color Saturation
White Clip – Black Clip
Micro-smoothing:
Light smoothing
Microcontrast

In my opinion, Luminosity and Light smoothing affects the photo more. So carefully adjust the sliders.

Increasing strength creates an artistic effect. Increasing colors saturation also increases noise.

Play with the settings. Don’t use the Default settings of Photomatix. I normally use the strength around 20 to get realistic kind of image. Be careful while increasing the color saturation. It adds more noise.

Break the Rules!!

After everything is over click PROCESS. Save the file as 16 bit tiff.

Post processing in photoshop

Next open the 16 bit tiff in photoshop. Adjust contrast, colors etc., using levels and curves adjustments.[In my case i added some yellow using curves adjustment]

One important thing you might have to do is reduce noise. you can use Filter –> Noise –> Reduce noise in photoshop.
There are lot of photoshop plugins available for this purpose. "Noiseware" , "picture code noise ninja" etc., use them.

Go to Image –> Mode and choose 8 bits / channel. Then save your image as JPEG.

DONE!!!!

comments and suggestions are welcome.

 

Infected With Virus ? May 30, 2009

Filed under: Computer — KARTHIK @ 1:08 am
Tags: , ,

Infected with Virus ?

Tools:

  • Ccleaner
    http://ccleaner.com/
  • Malwarebytes antimalware [MBAM]
    http://www.malwarebytes.org/
  • Spybot search and destroy [spybot S&D]
    http://www.safer-networking.org/en/index.html
  • Superantispyware free edition [SAS]
    http://superantispyware.com/

All the above tools are free, and constantly updated to catch threats. You can download, install and use all the three at the same time. You should not have any problems.

Note: Spybot S&D has a resident protection function called teatimer. It might interfere with your antivirus or make your system slow a bit. I normally disable teatimer.

http://www.malwarehelp.org/how-to-enabledisable-spybot-teatimer.html

Here is one more free tool from kaspersky. [updated daily]

http://downloads5.kaspersky-labs.com/devbuilds/AVPTool/

How to Cleanup ?

1. Backup all your important data. This is the first step because, if incase anything goes wrong you will be safe.

2. Use ccleaner to cleanup all your unwanted files in temporary folders. Ccleaner is a very small effective tool. Cleanup all files in windows temporary folders. [many viruses live in temp folders!]

some tutorials:

http://www.removingspywareforfree.com/article.php/Ccleaner_Tutorial_Page
http://www.ccleaner.com/help/tour

3. Turn off system restore. This is important because, if you cleanup malware ’system restore’ has a copy of it in its own hidden folder [system volume information]. So the malware is still in your system!

For XP:
http://support.microsoft.com/kb/310405

For Vista:
http://www.bleepingcomputer.com/tutorials/tutorial143.html

4. Boot your computer in safe mode.

Restart your computer
Press F8 key repeatedly
A menu with a black background will appear
Use arrow keys and navigate to Safe Mode and press Enter

http://www.computerhope.com/issues/chsafe.htm

5. Do a full system scan with your antivirus in safemode. Also do a full system scan with MBAM, SAS and spybot S&D.

hopefully all viruses in your system will be removed!

6. Reboot windows in normal mode and create a new system restore point.

Advanced:

Tools:

  • HijackThis
    http://www.trendsecure.com/portal/en-US/tools/security_tools/hijackthis/download
  • SDFix
    http://downloads.andymanchesta.com/RemovalTools/SDFix_ReadMe.htm
  • Combofix
    http://www.combofix.org/
  • GMER
    http://www.gmer.net/

How to ?

1. Do not use the above tools if you don’t know how to use it. Each tool has its own method. It is strongly advised to use these tools under guidance.

2. HijackThis [HJT] is an excellent tool. It shows a log from which you have to find out malware infections. It shows a list of startup entires, winsock entires, browser helper objects [BHO] , services etc.,

You have to google for the process name and find it whether it is legitimate or not.
These sites might be helpful for analyzing HJT logs.

http://www.hijackthis.de/#anl
http://www.systemlookup.com/lists.php

Here is a very good tutorial on understanding HJT entries:
http://www.bleepingcomputer.com/tutorials/tutorial42.html

3. SDFix and combofix are powerful tools. use it properly under guidance.

4. GMER is a very powerful rootkit detection tool.

Where to get help ?

For advanced troubleshooting of virus issues, you can get from online forums. There are lots of forums doing it.[you can register for free and get help]

They provide a step by step removal instructions.

Here are some sites i like:
http://www.bleepingcomputer.com/forums/
http://forums.majorgeeks.com/index.php
http://www.malwarebytes.org/forums/index.php

 

Some Useful Freeware May 24, 2009

Filed under: Computer — KARTHIK @ 7:14 am
Tags: ,

Some Useful Freeware

Here are some very useful freewares i use.

1. Regseeker:

A very powerful light weight registry cleaner. You can download it here.

http://www.hoverdesk.net/freeware.htm

2. Ccleaner:

A small tool that does all your cleaning task. Very effective tool. I use for a long time.

http://www.ccleaner.com/

3. Auslogics Disk Defrag:

A very fast disk defragmenting tool.

http://www.auslogics.com/en/software/disk-defrag/

4. ImgBurn:

A small program that performs all your burning needs. I use it many times. I feel it is better than Nero.

http://imgburn.com/

5. Notepad ++:

Excellent alternative to windows notepad. I use it always.

http://notepad-plus.sourceforge.net/uk/site.htm

6. Pidgin:

I started liking it after i used Linux. I have a google account, yahoo, ICQ etc., I can integrate all into one — Pidgin.

http://pidgin.im/

7. Revo Uninstaller:

Normally when you uninstall a software, it doesn’t remove itself completely. Some traces in form of files and registry keys are left over. To get rid of them I use this tool.

http://www.revouninstaller.com/

8.Mozilla Firefox:

I never use internet explorer. I always firefox. I started using when version 0.5 or 0.7 [if i am not mistaken] is out. Now version 3.0.10 is out. A good alternative to this is opera.

http://www.mozilla.com/firefox/

9. MBAM and Super antispyware:

These are two tools i use to do a manual system scan once a week. Very popular ones updated daily.

http://www.malwarebytes.org/

http://superantispyware.com/

10. Avira antivir personal:

This is a free antivirus from Avira. I like this very much. It doesn’t have a built in firewall. I use Zone alarm free firewall.

http://www.free-av.com/en/trialpay_download/1/avira_antivir_personal__free_antivirus.html

These are just what I use. If you want more useful freeware, spend some time here.
http://www.techsupportalert.com/