How a digital camera captures an image

We ,as humans,see light, but things(the retina) works within our eyes and convert light into signals, so that they can be transmitted to other parts of the body. For a camera, the same theory applies. How does it work without films as in traditional cameras? In my chemistry classes, I learnt that there is some silver chemical or something on the film, and when light falls on it, image is produced on the film.But for digital cameras the film is replaced by a semiconductor. Light falling on the semiconductor is used to store the image (SLR cameras have mechanisms for cleaning itself internally) The 'semiconductor' is called the sensor, which detects the presence of light. A sensor does the purpose of a retina of the eye. That is , it finds the presence of light, and converts into digital signals.

Usually a Charge Coupled Device (CCD) sensor is used in our 'point-and-shoot' cameras. It is nothing but something that converts light into electrons.It can be considered to be a 2-D array of light detecting cells. An Analog-to-Digital Converter(ADC) calculates the charge at each point(or cell) and converts into binary form.

A CMOS sensor

Another sensor used is 'Complementary Metal Oxide Semiconductor (CMOS)'. It does the same thing, but it does not need an ADC, because the signals produced are already digital. CCD sensors are used in our normal point-and-shoot cameras, while CMOS is used for high-end SLR's.

To put it in simple words, the camera converts light into an image in simple steps :

1. Light comes in through the lens
2. Falls on a light sensor
3. Sensor converts light into digital signals (In CCD sensor, an extra ADC converter is needed)
4. Converted to binary form
5. Stored as image

Simplifying photography

Now that many have entered the 'field' of computer science, I thought of blogging about a new field - Photography. I have been doing a little bit of reading and experimenting myself, and with some blogging here , I hope I can pass on whatever I know. And get to learn more too.

It is easy to understand the working of a camera ,if we compare it to the working of the eye.
The working of a camera is like that of a fish but not like the human eye. Because lens of a fish is like that of a camera.
The human eye focuses on objects by changing the curvature of the lens.
A camera focuses on things by changing the distance between the lens and the sensor. That is why,in a camera, when we zoom in and out, the lens pops out an goes back in .
And when the human eyes zoom on things, nothing pops out (that was just to make things simpler).

I hope to be using this comparison in the later stages. (I shall try making a clearer image, if i get enough free time)

aXXo is a guy

found this interview on the net..was just curious wat aXXo really was

For those of you who never heard of aXXo, he is responsible for hundreds of DVDrips that find their way to millions of PCs around the world. Most of the rips are 700MB, made to fit on a single CD. Some have criticized his preference for single CD rips because of the inferior video quality, but most pirates agree that he does a great job.

Earlier this year aXXo temporarily stopped uploading movies because axxotorrents.com was trying to profit from his name. After a few weeks that site went down, and aXXo continued releasing DVDrips.

Most of the time it is impossible to track down the source of DVDrips, especially with people from “the scene“. But aXXo is not a member of the scene, and although was not very talkative either, he was at least willing to answer a few questions.

TorrentFreak: When did you start ripping / uploading DVDrips?

aXXo: When I was about 15 or 16 I got into backing up my old DVD’s. History from there.

TorrentFreak: What motivates you to share these movies?

aXXo: Why not? If I see a great film I believe everyone has the right to be entertained by it.

TorrentFreak: Don’t you think that ripping and uploading these (copyrighted) movies is wrong?

aXXo: No not really. It was just for me and some mates at first.

TorrentFreak: Are you alone in this, Or do you get help from others?

aXXo: No help, It’s all me.

TorrentFreak: You seem to prefer 700MB rips, and not higher quality ones, why is this?

aXXo: Very little (if any) Loss of quality, and will fit on a Single Music CD.

TorrentFreak: On which torrent sites do you release this movies, and why not just on one?

aXXo: There are quite a few I release to. Many people prefer one site over the rest, and I want to spread these as much as possible.

TorrentFreak: What do you think of sites that (mis)use your name, like axxotorrents.com?

aXXo: This is a touchy subject. I have nothing against any of them, it was a complete misunderstanding and the issue has been cleared up. They are reliable, And I have checked every torrent on there thus far to be real.

TorrentFreak: How can people tell if the torrent is not a scam, or a fake torrent?

aXXo: If it’s a RAR archive, It’s not mine. My rips will contain 2 or 3 files. One info and one .avi files. On occasion a .txt file but that will stop.

TorrentFreak: Where do you get the movies, and do you use scene releases as well?

aXXo: …

TorrentFreak: Do you think that distributing these (copyrighted) movies is morally wrong? That is, do you consider sharing shows to be the same as stealing?

aXXo: Thank god in this country we don’t believe in copyright infringement. It’s just sharing entertainment, nothing more.

TorrentFreak: Okay, perhaps this one is easier to answer. What is your favorite BitTorrent site?

aXXo: I don’t have one. Darksiderg.com is where my original releases are, But I release to many. Superfundo, Demonoid, MiniNova, The Pirate Bay.

TorrentFreak: Anything you want to add to this?

aXXo: Upload what you’ve downloaded, and then some.

TorrentFreak: Thanks!

aXXo: You’re welcome.

Very simple way to save youtube videos

A few months back, a post was made about an 'easy' way to download youtube videos. But since then easier methods have been found. And here is one of them.

But you need to have the Mozilla Firefox browser, which can be downloaded from :
http://www.mozilla.com/en-US/firefox/

And once you install your browser, you just need to install an add-on or plug-in called the Video download helper, which should be available here :
https://addons.mozilla.org/en-US/firefox/addon/3006

Just install it, and restart Firefox. You are ready to save your youtube videos in the .flv format.
Goto the youtube page which contains the video that you need. And you can see an icon on the right side of the address bar. This icon gets animated when there is downloadable media in any page. so once you are in the page, the video gets animated. And when you click on it, a list comes up and just click the
videofilename.flv
and the video gets downloaded in the .flv format, which can be played in the kmplayer, which should be available here :
http://www.kmplayer.com/forums/showthread.php?t=4094

And you can enjoy your favorite videos anytime, saving all the extra data transfers dat you waste everytime you wanna see it. And its always better to save the video first onto you HDD nd watch it before watching it on the browser. Saves you data transfer.

Thank you for reading. Feel free to comment

Using subtitles for your movie files

Yesterday KK askd how to view subtitles while watching movie files.

First of all you need to get ur subtitle file(usually .srt files)... i use www.subscence.com for getting my subtitles.

If you are using the KM player, then viewing subtitles is easy. Just drag and drop the .srt file onto the player, just like you would do with a movie file to view it. This is the easiest way, and i recommend the km player with the k-lite codec pack.(http://www.k-litecodecpack.com/)... this thing play 99% of all file formats.

I dont think the drag and dropping subtitles work with the Windows Media Player. In this case, you just need to work with the filenames a lil. Just place your movie file(XYZ.avi) and ur subtitle file(the .srt file) in the same folder. Now just rename your .srt filename into XYZ.srt.

This should just do it right hopefully. Getting the subtitles to sync with the movie is another headache...which you can take ur time and solve ;-)
If you got other good sites for getting subtitles, please post them.

Cheers

Amazing sound

got this from dish
these are special kind sounds... rite now dunno da name.. and cant get him on phone... but blogged so dat i don forget this later

But just download this file. and close your eyes and listen to it using ur headphones....WITHOUT HEADPHONES YOU WONT GET ANY EFFECT
http://www.rewarder.co.uk/virtual_barbershop_n.mp3


So go ahead download, close ur eyes, listen

Very Very easy Virtual Network Computing in Ubuntu

Million thanks to sk for posting about VNC. I wanted to do that for a long time but was plain lazy. The following "guide" explains how to setup a VNC server in ubuntu and how to connect to another VNC server from ubuntu to any other OS.

Setting up VNC server in ubuntu

Ubuntu comes with Real VNC server installed by default

Goto System->Preferences->Remote Desktop. You'll get a window that looks like this

Make sure the first option is checked. All the other options are optional. Thats it. You know have a Real VNC server running on your ubuntu box which other users can connect to using your ip. To get your ip in ubuntu open Applications->Accessories->Terminal and type in ifconfig.

Connecting to another VNC server(on any OS) from ubuntu

Thankfully Ubuntu also comes with Real VNC viewer installed by default. For example consider that the ip of the VNC server you want to connect to is 202.164.133.28

Open up Applications->Accesories->Terminal and type in vncviewer 202.164.133.28 and press enter


Note: If you are connecting to a VNC server on a windows machine and this command gives an error turn off "encryption" in the server.

If you are requested a password enter the password provided by the admin of the VNC server.

Voila! Uve succesfully connected to the VNC server.


Note there is a slight discoloration in the desktop being viewed remotely. This is because vncviewer is by default set to 8 bit color depth for increased speed during the VNC session.

The most interesting fact about VNC is that it is platform independent as VNC is written in Java which is a platform independent language. The above screenshot shows aarti's XP desktop being viewed from an Ubuntu desktop.


May the source be with you ;)

Easy virtual network computing in windows

(da pic shows my desktop as viewed by sreejith on his system, the pic was taken on his cellphone, so da quality of pic is not so great :) )

Virtual Network Computing (VNC) is simply sitting in your home and controlling a computer which is connected to a common network, like a LAN or even the internet. It can be helpful when you need assistance from someone who is sitting far away. You can grant permission to dat person so dat he can share control of the system and he could move around with your cursor, use that keyboard and all general stuff.... reading theory is boring, so I will go onto the practical’s. (Check out da apache 160 rtr ad )

Rj has been doing this for a long time on the Ubuntu, I got it working in windows today. And it’s pretty simple and basic. To try this out, you need two people who are connected to da net and have da software. Here is how you go about it:

• Goto http://www.realvnc.com/ and find the right download for your OS (I tried with a trial enterprise edition.
• Once you are done downloading, install it. Just follow all the instruction and keep giving next-next-next. For ease of access place an icon of the ‘VNC viewer’ in the desktop.
• Once both the people are done with installation, goto start and run the VNC service. A white logo appears on the system tray (beside the clock). Double click dat and the following window pops up. Just for seeing it work, use ‘No authentication’.
• 
  
• Now connect to the net. And one person, say A, can be the viewer and the other person’s, say B, system will be viewed and controlled by A.
• Now what B has to do is move the cursor over the VNC icon on the system tray (just hover over it, don’t click)... and when the cursor is there a tooltip pops up having 2 addresses. Take down the first address (dat is before the comma). For BSNL, ppl it will generally be 59.xx.xx.xx . This is the ip that has been allotted to your system.
• Now B can send this ip address to A (thru yahoo messenger, orkut or whatever). Now A has to run the VNC viewer from the desktop or the start menu. And a server address will be asked : here input the address obtained from B (and from the drop down list select ‘Always On’, this was da config dat I got it to work, have not worked around with it much at the time of blogging). Once this is done, a Real VNC window should open and person A should be able to view and access person B’s system.
• B can know that a connection is established when his RealVNC icon turns black.

This is the basic setup that I had it working on. Hope it works for you too. Once it has started working, make sure you enable password encryption for your safety.

Special thanks to

Rj – for letting me know dat such things exist

Dish-for working with rj and inspiring me to try it by showing a pic... and taking a seminar on it soon.

Sreejith and Aarti for giving your precious time in working with me and testing it and doing all sorts of alambu on my system.

TRY IT... its worth it and its fun.. ask aarti, she will tell you J

*-*-PeAcE-*-*

This is something dat i did, i cannot say how much of the above mentioned is true or can be classified as valid information or data.. ALL I KNOW IS THAT IT WORKED FOR ME.

Save your Youtube videos to your hard disk

There are maybe over a 100 ways of doing this, but this is the real dummy way (dummy means ‘somone’ who doesn’t know much)

You need two software’s for proper working:
Quicktime : http://www.apple.com/quicktime/download/win.html (i would say download the one with iTunes even if you don’t have an ipod, it helps better organizing)
A converter: http://www.dvdvideosoft.com/guides/dvd/convert-YouTube-FLV-video-to-iPod-MP4-video.htm (from da site download the youtube to ipod converter)

• Install both the above software, open the converter software
  Goto youtube


• Take the page of the video you want.


• On that page there will be a box named URL.


• Copy the link in dat box and take the converter software.


• Paste it in the ‘Input File or Youtube Video’. In the output field , you know what you should do (if you don’t, wat can i say). The ‘Devices’ and ‘Presets’ lists are for tweaking quality, just play around with them the way you want to.


• Click ‘Convert’. Open File and view your video.


• Hopefully it plays. Don’t blame me if it doesn’t. :d

I know da pic sux... afterall i havent got 100 readers, so wont be a prob