Wednesday, July 27, 2005

DIP TAship

I have taken up DIP TAship for this sem. There won't be any tutorials as sir told me, I will basically be checking assignments, scrips and clarifying doubts.
Now since there are many surprize takers of this course, I should clarify somethings unofficially. I must say this course is not a very advanced course and very high level of mathematics background is not required in it. The content is mostly logical and easy to understand and also fun to implement.

Now as usual when I get a TA ship I want to make sure that my bad experiences for the course are not repeated for the students. This of course stands for only those who are genuinely interested in learning something from the course rather than just getting 4 cheap credits. But the course as it was done for us didn't give us much of excitement to explore anything.

The reasons for that might include our nonchalant behaviour but the main reason I feel was the bad teaching by the then Prof. DIP is somethings that could be made very interesting by showing some good effects created using various techniques and made vary boring by just showing some slides with loads of text describing the algorithm of those things, and almost everything follows logically if the concepts are clear, which was fortunately not the case with us. The surprizing part is that we never got the excitement to code any good technique, we only did the very little which would allow us to have working code in Matlab, mostly using heavy matlab functions and learning nothing about the implementation of them.

The problem arose because of unclarity of the assignments. We never knew what we were supposed to learn from the exercise the result of using some algo? or the basics of the algo? Since doing the first was like testing some small code in matlab, we ended up doing that most of the time. So it's a must for the student to get it clear what is the objective of the assignment, otherwise doing it may lend u nowhere.
If you hesitate asking the prof ask the TA, if you hesitate in that too, Then you are probably doing bad to youself.

If someone takes this course for getting in to Adobe as one of my friend guesses, I must warn that improper knowledge is more dangerous than innocence in the topic. So either do the course properly or skip it. Further I normally dislike cheating and malpractices. I don't like ppl getting more than what they deserve 'coz it spoils their habbit and the spirit of other hardworking ppl.

ooking forward for some great learning and teaching experience. Any comments(even anons) should be welcome.

The week that was

I can realize that time's pace already seems to get higher. Last week went without any progress, basically stuck with some implementation detail in a paper and debugging the code. Only to realize that the code was right but there was some problem in the understanding. That leaves the algo unimplemented for some time. Sir asked me implement the better and more reliable paper.

Had two parties at the weekend. One was Maliha's Birthday treat and her new house's inaugration(?) ceremony, had great time going to her house near Mehdipatnam trippling on Bapu's bike, (Me, Sachin and Bothra). There we waited for around 1/2 hr for the gifts to be brought in by Dixit and Rocky. Patke and AC joined us waiting too. Then we had some BC for around 2 hrs sitting on the roof of the house.

Next day Bothra took us to the Country Inn(?not sure?), Its a good hotel and the buffet was really nice. Photos should be hosted soon if only my flickr uploader gets updated with the new APIs.

Sunday, July 24, 2005

KIO::http_post and KMD5, md5sum usage learnings

I needed MD5 sum for a given string for the api-signing(irrelevant) of flickr's new Authetication API. Simply guessed KMD5 and searched it and woooo!!! it was there.
Usage of KMD5 is quite well documented in their documentation page, what I used and what worked perfectly well for me :

#include
QString final("this is just an example.");
const char *test=final.ascii();
KMD5 context (test);
kdDebug()<< "Test Hex Digest output: " << context.hexDigest().data() << endl;

Since I was not getting proper response from the server on using the MD5 sum, I enquired and came to know that the command md5sum in Linux takes the terminating \n of the string in to account if not told otherwise. i.e
the output of echo "this is just an example." | md5sum
is the md5sum of this is just an example.\n
to get the correct answer the command should be echo -n "this is just an example." | md5sum
This might look very trivial now, but even when I copy pasted string in to a file and checked the md5sum the \n was creating the trouble. So be careful about the \n thing. Also if you can suggest how to get rid of this \n from a file in vim please let me know, I tried backspace etc but it didn't give correct checksum.
KMD5 works without any problem the QString converted using latin1, utf8 etc anything works well. The trailing \0 is not a problem as against what I initially guessed.

Now KIO::http_post. I basically don't have much idea about its implementation details , but only that it is used for posting html form. I wanted to send a form with a query string, so I suspected that I should use content type of application/x-www-form-urlencoded and encode the query string data in to the second argument somehow, I was wrong, that all is not needed, the first argument is a KUrl and it can handle any complex query string as a value so my final code looked like this. (I am still not sure what kind of data is to be send when I want to send the form data using second argument, I guess it should be the utf8 format.)

QString final_url=url+"/?"+queryStr;
QByteArray t;
KIO::TransferJob* job = KIO::http_post(final_url,t,false);
job->addMetaData("content-type", "Content-Type: application/x-www-form-urlencoded" );
connect(job, SIGNAL(data(KIO::Job*, const QByteArray&)),
SLOT(data(KIO::Job*, const QByteArray&)));
connect(job, SIGNAL(result(KIO::Job *)),
SLOT(slotResult(KIO::Job *)));

This page is just placed so that anyone who faces similar question finds a solution. In case the details are inaccurate please let me know I will apply them with acknowledgement.

Thursday, July 21, 2005

More on M$ front

I have heard that whatever you through in air, comes back around. Its probably from Noam Chomsky (My friend Ramneek reads his book and he told me). The same seems to be happening with Microsoft now.

Firstly there is this news of Google hiring another top M$ exec and M$ suing Google for that. Its a funny behaviour potrayed by M$, which itself has the tradition of hiring great minds from the competitors. Read this
Insightful comment on slashdot.

They do it not only to Industry but even to Academic institutes, wooing Professors to work for their research centers around the world leaving the universities.

Second, today this interview from M$ Linux Strategist has come up on slashdot which demonstrates how poor their knowledge of Linux and OSS is.

Finally this news and graph makes us Linux Lovers happier. Linux Trounces Windows Mobile in Smartphone Shipments

Movies review

Was not able to post my reviews on some movies I saw recently, here is a short list of them.
Serendipity --> Nice movie. Don't put too much logic, its just about finding your true soulmate etc. stuff

Maine Pyar Kyon Kiya --> we went to this Sai Ranga theatre in Lingampally just for sake of an outing. Having already read the reviews of movie I knew it was gonna be a senseless comedy but its was okay. Since I left my brain at my hostel while leaving I enjoyed some of the funny incidents in the movie though they sucked most others.

Madgaskar ---> Its not a great animation movie. The basic storyline is not very impressive.

Black Friday --> This movie is awesome. As they say one of the great ones rarely produced by Indian cinema. Its about Bombay blasts in 1993, the best thing is that they don't go about teaching the secularlism throughout the movie, they simply show what was found out during the investigation. One ver y well put scene is where the ppl involved in the blasts found a bomb in their own car which was timed to explode soon.

Monday, July 18, 2005

Smallest Linux Computer::Picotux

Better go to the homepage to see the specs.

The dimentions are : (35mmÃx 19mmÃx 19mm) it runs ucLinux.

Thursday, July 14, 2005

BTech Requirements Completed...

ISAS shows my B Tech requirement completed. All the grades are out and my final CGPA is 8.52 and I am happy to have crossed the 8.5 mark.
In some sense I am already a graduate or specifically an Engineer but practically I will get the degree by next year only when I finish my integrated MSbR. So I am still an undergrad. :(

Monday, July 11, 2005

Telnet access Motorola A768i phone from Kernel 2.6

I had almost given up connecting my phone by USB on Linux (I was told and I tested it not working on my FC2/3 machines)until yesterday when I landed up at this post by simon. Where he describs a patch in kernel 2.6.12-rc4 that enables usbnet to work properly in Linux without need of any extra usblan drivers at was required in kernel 2.4

I Got the kernel 2.6.12.2 from kernel.org and installed it. Just checked that everything relating to hotplug and usb was selected in kernel config. If you think compiling is a big problem it's not, you need just these commands and some time:
tar -cvjf kernel-2.6.12.2.tar.bz2
cd kernel-2.6.12.2
make menuconfig #(if you really wanna enable/disable default config of kernel).
make
make install
And your grub file will now contain your new kernel entry,

After booting in to new kernel, I just plugged in my phone, usb connection mesg was shown on the console. lsusb showed me the phone identified. This much was working even with 2.6.9 kernel, what mattered was that the usb0 interface was not getting created. Which happened without any problem in new kernel. I just checked "ifconfig usb0" and it showed the device. I don't know if the command echo "AT+MODE=99'>/dev/ttyAMC0 was needed on my phone as suggested in simon's post.

Then started the fun part. To assign an ip to usb0 I gave command ifconfig usb0 192.168.1.2
and then set usbnet option in setup of my phone to on. It accepted IP address 192.168.1.1.
I did telnet 192.168.1.1 and was able to login as root without any password. Did lot of exploration on the phone seeing all the directories. important files etc. Its real cool stuff to play around and see same Linux powering ur box running on such small hardware.

Some good stuff to play around.
1) As with all(mostly) devices this phone provides you only windows .exe to do things like syncing, updating etc. But if you really hate to boot to that OS you can do without it. The phone probably uses(read point 3 below too) samba for enabling write from windows, so from your linux box just smbmount your phone no password required, just press enter when prompted e.g

000_0490.JPG
smbmount //192.168.1.1/home /mnt/tmp -o username=ezx ;# understood by reading samba config file ;-)
To get to your custom files and folder as shown by the filemanager app.
And
smbmount //192.168.1.1/system /mnt/tmp -o username=ezx
To get to the / you have to give this command. I must warn you to be carefull with writing files etc.
now you can simply play with /mnt/tmp/ as you like to and as the file/dir permissions allow you to do.

2) Run Nmap to see what the device is offering, its os fingerprint, its uptime etc.
nmap -o 192.168.1.1
000_0488.JPG

000_0487.JPG

3) I could see ftp in above command's output, as expected next command was ftp 192.168.1.1
by after getting "connected to 192.168.1.1", I was told device closed the connection. I didn't try much further. This could also be one possible way of file tranfer by syncing software.

4) Linux hackers love this /proc so I investigated it for a while, to see details of my device.
cat /proc/meminfo
cat /proc/cpuinfo
To realize it was running on Intel XScale. and kernel is 2.4. something
000_0486.JPG

cat /proc/filesystems
To realize that it supports nfs and ext3
000_0485.JPG

5) cd /dev/ ; ls
000_0480.JPG

shows lots of devices I wonder what they are used for.
000_0482.JPG

6) The phone seems to start as normal linux device and autologin to user ezx and startup is mostly what is given in this user's .bash_profile

here is
ls /bin
000_0477.JPG

Saturday, July 09, 2005

Multiexposure :: Cool imaging technique.

I didn't study details of that, but the images posted by ppl on flickr promises the MExposure is a great technique. Check out these example images.

Man seeing himself lying on the floor.


Do I need to describe it?

You can search other images on flickr with tag doubleexposure, by clicking here. Look for other similar tags too.

Wednesday, July 06, 2005

Shitty Service(s) by Idea Cellular

I have been using idea for around 40 days now. As expected I should give some feedback/warning to them and their prospective customers. I should start from the beginning.

Getting the Sim card was a breeze just submitting a photocopy of passport and it was done. I got 7 days validity with 99/- card, and 19/- Rs talktime.

Rates were not given much heed as I wanted a temporary connection till my BSNL sim application was taken care off, but they need a mention as a kind of feedback 2.75/- PM for any outside AP call. 1.75/- for local non Idea phone/landlines. I soon realized I had to apply some scheme to make STD cheaper for me and I opted for Diet STD topup. Rs 2 PM on any outside AP call.

I was feeling great when I was just able to get a good scheme of 1200/- Rs recharge with (almost) full talktime and 6 months validity before I went for a vacation to attend a marriage in Banda (M.P)
I didn't get sufficient time to enquire their Roaming, charges so I stayed away from making much use of phone for outgoing calls in my Journey( It included Maharastra on the way with Airtel as the vendor) What seemed funny was that when I landed down at Nagpur to take a bus to Jabalpur, I saw two bill boards one of them from Airtel thanking customers for making them biggest Cell providers in Mah and another from IDEA again thanking customers for the same thing but with a bar graph ??.

So I reached my home in the night and called up customer care to know what were the charges etc. In MP I got Idea network, so I expected 12345 to be dialed for the customer care and dialed it. They had a huge sequence of menu operation and I had to press around 5/6 digits(options) before I could speak to a customer care executive(CC), which happened at around 5 minutes after the call. I just asked the CC as to what I have to dial to know my balance (it was 2121 in AP but that was not working there), the fellow told he will give me the number, when I asked him if there was no toll free, short number to do so, he informed me nothing was toll free on roaming, even the call I made to him is charged, It was already more than 6 minutes before I came to know this and Damn it costed me 28/- to call customer care. Coudn't they simply send me an SMS about there tarrifs and billing etc info when I go to some other network? They do send a lot of spam SMS(regarding some offers) at least.
Now when I came back from the vacations I realized I had spent around 130/- bucks in making/recieving some 5,6 1-5 minutes calls.

Soon I realized making local calls was getting tougher, so I thought of taking a "Topup" for local calling, I enquired the procedure, and based on that I sent a SMS to 4444 with mesg MOBILE, to my wonders no action was taken till next day, I again enquired CC told me that I can't opt that Topup as I already have Diet STD topup. Next day I again enquired if there was some other way to get my local calls cheaper I was told I can apply for Mobile topup, and I just have to pay separate 45/- rental for each of the topups, so I applied and this time I got the confirmation: you can now make local calls at 49p/m. I was glad, but that was not for long and I realized the mesg meant nothing when I called local phone next evening and was charged at 1.75/- Rs/M. Of course frustated I called CC again and this time the guy there didn't admit there systems fault and said I didn't send any SMS and made me send the SMS again. What the heck? Next day again, no action was taken so I called CC again and this fellow tells me he will make a request from his Comp and it will be activated by 12 AM.
Soon I got a call that they will be waiving my Diet STD for enabling this Mobile topup and now that I had made the request already the system will decide what to do. Meaning If I don't want to lose my Diet STD Topup and just stay out of this new one, they can't really do anything. It was for system to decide. It might subscribe me to Mobile or might leave things as such. Shit are computers given so much control by Foolish programmers?
Today I was finally informed that they have now enabled Mobile topup on this number and have cut 45/- Rental for both the topups? Shit! These ppl r really insane.

Tuesday, July 05, 2005

Check your mail signature...

I remember myself keeping large signature with lots of details about myself including my room number etc, Now I don't have any default signature. IIRC the realization came when I saw one of my mail in some HTML mail archive. It had details of my address etc.

Everyone becomes aware of how useless such signature of our are, over time, but by that time probably mails sent by you to public mailing list have made it to google's memory and a appropriate search query might give details about you which you wouldn't like to give to ppl.

I have seen one of my friend with a signature which give his email id in around 5 sites, his room number, his phone number, mobile number, etc etc. many other ppl do it to varying extent, ppl should realize how senseless these things are to the reciever of the email. Even if you don't care about your own privacy information, do care about spams, unsolicits calls on your cell, unsolicit messages on your phone(they are going to be a big problem as programmes searching for email addresses starts understanding mobile number too and map the number to the email address for the person).

Movie Sarkar: Awesome

Really nice movie, No BC, Yes those Indian tunes do come up at times, but they don't bore you much with all time pass customes etc and at the same time there are no songs.
Some great dialogs, "Kaam chunaab se karne chayiye dabab se nahi" (Rasheed),
"Tumey mallum nahin mein do din mein jail je bahar aa jayunga",(Chief Minister), Reply: Bahi to mein chahta huun (by Abhishek).
"Mein to Chala Tamil Nadu, Tsunami ke baad jo koi gaav bach gaya hoga usme settle ho juyynga, Tum bhi Dubai nikal lo, (wahan par sand mein chip jana), aur tum to gaye kaam se, tum to agar mar bhi gaya to Sarkar tumhe bapas Jinda karke marega, aur pandit tumhari bohut jaldi God se meeting hone wali hey" :) (Discussions between the Villians).

Sunday, July 03, 2005

Patents...

I don't like software patents and pray that they are not legallized
in European Parliament tomorrow( you see most of the OSS projects have
contributions from Europeans).
While reading some research paper on my MS topic, I came across the line
"A large number of techniques for Chromakeying have been under patents...."
suggesting the problems ppl face in understanding and improving these
techniques.
If you need to search for some patent, you may find this site quite
useful.
http://www.patentstorm.us/

If you are European visiting this blog please take whatever action
possible reading http://yro.slashdot.org/article.pl?sid=05/07/02/1451233&tid=155&tid=17

Friday, July 01, 2005

About Resolution : printing and viewing

Somu told me some good info about these things when we were discussing
about the use of a 5 MP camera that I recently got.
Resolution of a photograph is something like 2500x1900 (ignore exact
number please), when we see it on a monitor with resolution of 1024x768 we
have to scroll to see the whole picture. Now when we print it on a paper
we will not get that big a photo as our monitor is( forget about the
scrolling part). Why?

Basically monitors have a dpi (dots per inch) value of something like 72.
That means if there are 720 dots they will be put in 10 inches. Now in our
photo case they are something like 2500 dots which will mean around 30
inches of view, so with a monitor of view size 14 inch we need to scroll
for another 16 inch to see the photo completely.

Now coming to case of a printer, the printer has a resolution(?) of around
300 DPI which is roughly 4 times that of a the monitor, that should mean a
2500 pixels which should give around 8 inches of photo print.

So you will not get more than 8inch by 6 inch photograph by a 5 MP camera.
Now its clear why ppl look for better resolution.