Saturday, December 10, 2011

Dev Anand - The Eternal Hero

"I am not a fan of Dev Anand. But I like many of his classic old movies." I think this would be the state of mind of anyone who has seen a lot of classical Bollywood movies. I started liking a lot of old Hindi classics and started building a collection. The songs in the movies and their placement in those movies propelled my interest in the old movies. It was also due to the poor quality of songs in present Hindi movies that I developed keen interest in the old ones.

Dev Anand deserves a special place in the history of Hindi movies. He was monotonous in his movies in his own unique way. But it still worked. His best work till date is undoubtedly, "Guide" starring Dev Anand and Waheeda Rahman. Based on RK Narayan's novel of the same name, it was a very subtle romantic movie with great songs like "Gaata rahe mera dil", "Din dhal jaaye", and "Aaj phir jeene ki tamannaa hai". Kishore, Rafi, Lata, and SD Burman would have taken the songs of this movie to a different plane altogether. A must watch movie for anyone even after almost 50 years since it was first released.

The second best movie of Dev Anand is the thriller, "Jewel Thief". Being one of the best crime thrillers of that era, it starred Dev Anand, Ashok Kumar, Vyjayanthi Mala and Tanuja (Kajol's mom). Suspense, romance, and crime made it a compulsive watch for millions. Songs tuned by SD Burman were again major attraction of this movie. Songs of this movie such as "Yeh dil na hota bechaara", "Aasman ke neeche", "Dil pukaare", and "Hothon mein aisi baat" are still favorites of Hindi film song lovers.

Another movie of Dev Anand which I liked is an underrated love story - "Tere ghar ke saamne" starring Dev Anand and Nutan. Though the story is a simple comical romance with lot of melodrama, it had some stunning songs tuned again by SD Burman. My personal favorite is Rafi solo, "Dil ka bhanwar kare pukaar" which was shot exquisitely inside Qutub-Minar. The expressions of Dev Anand and Nutan in this song are a treat to watch. The title song, "Tere ghar ke saamne", a Rafi-Lata duet is also still popular.

Other movies I loved of Dev Anand are CID, Asli Naqali, and Hum Dono. Some of the memorable songs of Dev Anand are "Main zindagi ka saath", "Phoolon ke rang se", "Shokiyon mein ghola jaaye", "Hum hain raahi pyaar ke", "Chod do aanchal", "Accha ji main haari", and "Abhi na jaao chodkar". He died few days back after leaving us memories of his unforgettable movies over decades. We should thank him for leaving behind to us so many great movies with a lot of eternal melodies over time. There can never be another Dev Anand in Hindi films.

Sunday, November 13, 2011

High Dynamic Range Imaging - A Technical Overview

             Due to the digital revolution, analog cameras are rarely used these days. Digital cameras provide us sophistication in the sense that one can review the shot picture immediately apart from making any changes to the picture. Cost and expertise required for one to use digital cameras is minimal. These benefits of digital cameras over the analog cameras have made them ubiquitous in the imaging. Digital imaging has become the most wide used term at present and no one bothers much about analog imaging.

           Real world scenes have a range of brightness levels so high that common digital capture devices are unable to capture the entire range. This drawback is mainly due to the restriction of capacity of the each sensor element present in the camera sensor array. Analog cameras can however capture higher range of brightness levels than common digital cameras, as the brightness levels are recorded in a continuous form through burning of oxides in the film.

There are digital cameras which can capture high dynamic range (HDR) scene information in a single snapshot such as Spheron VR camera. However, such cameras are very expensive at present. The challenge is to enable common low dynamic range (LDR) digital cameras to capture the HDR information. We shall now look at the new imaging paradigm called HDR imaging which enables one to capture higher dynamic range even with the common LDR capture devices. The advantage with such an approach is that the cost is less compared to re-designing the imaging sensor.

A real world scene which has both brightly and poorly illuminated regions is said to be a HDR scene. If we take multiple images of the scene using a digital camera by changing the exposure times, we would be able to capture all the details of the scene. Auto-Exposure Bracketing (AEB) feature in common digital cameras let one capture this sequence. However, the details of the scene are now distributed across all these multi-exposure images. We need to appropriately weigh the intensity values of these images to capture all the details in a single image. This process requires us to remove any non-linearity introduced by the digital camera before weighting the intensity values.

Many commercial software products perform this task. Some of them are HDRsoft Photomatix, pfstools,  and Adobe Photoshop (CS2 onwards).  Even recent releases of Matlab has functions such as hdrread, hdrwrite, makehdr, and tonemap to achieve basic HDR image operations. HDR images are encoded in formats such as Open EXR (.exr) and Radiance RGBE (.hdr)  which store a floating point value at each pixel location. The generated HDR image is then subjected to a process called tone mapping for display in display devices which can understand only LDR content. 

Problem in multi-exposure image capture arises when one needs to capture a dynamic scene. Real world scenes are dynamic (objects in the scene are in motion). Even an expert photographer does not have any control over the movement of objects in the scene while capturing multi-exposure images. If the scene changes are not detected in the multi-exposure images, the final HDR image will have artifacts called ghosts. Several de-ghosting algorithms have been developed which eliminate such artifacts due to motion in the scene.

The real challenge for HDR imaging in future is the development of fast algorithms which can produce artifact-free HDR image corresponding to both static and dynamic scenes. Real time tone mapping operators are also a challenge which can then enable HDR images to be visualized in common LDR displays. Inverse tone mapping techniques, which enable existing LDR content to be visualized on HDR displays, are also of much interest to the research community.

Reconstruction of High Contrast Images for Dynamic Scenes


        Our recent work titled "Reconstruction of high contrast images for dynamic scenes", published in The Visual Computer journal, provides a novel solution to the high dynamic range (HDR) imaging problem for dynamic scenes. The journal articles are accessible to all without subscription till Dec 31st 2011. So you would be able to download the article from the link The Visual Computer article.  I have posted a review article, "High Dynamic Range Imaging - A Technical Overview" which I wrote for IIT Bombay magazine called "Background Hum". The review article would motivate one to read this recent journal article and understand it better apart from providing a glimpse of the research I have been doing for the past five years.
   

Tuesday, September 27, 2011

Change of Momentum?

Men's tennis is in a major transition period due to the unexpected but well deserved rise of Novak Djokovic to the top of the rankings. No one would have expected Novak to win 3 Grandslams at the start of this year. In 2010, Nadal won 3 Grand slams and Federer won 1 Grand slam and the ATP tour finals. I was among those who felt that the Federer-Nadal rivalry will continue in 2011.  This Djokovic era has certainly made following tennis even more exciting.

Djokovic has raised his level of tennis from the Australian open and has never reduced the intensity. This probably took both Federer and Nadal off guard. Djokovic's winning run made them rethink their strategy as both used to dismiss of Djokovic quite easily over the past 4 years or so. The only major loss in a completed match for Djokovic was against Federer in the French open semi finals. It was more due to the exceedingly better performance of Federer that day than anything else. I never thought Djokovic would perform this well in clay even though he lost the match.

Apart from that, Djokovic has dismissed Nadal in all the matches of 2011 including the finals in Wimbledon and US open (on all surfaces). Nadal probably does not have any answer at present to the constantly improving tennis of Djokovic. Even Federer was never beaten by Nadal this consistently over the years. Only man to come close to challenging Djokovic this year was Federer. Federer should have won the US open semi final match having held 2 match points on his own serve. However, Djokovic has slowly imbibed the habit of rising from any position to win matches which is the hallmark of any true champion. Unfortunately, Federer and Nadal are at the receiving end now.

ATP tour finals is just about two months away. Top 4 (Djokovic, Nadal, Federer, Murray) have already qualified. Djokovic goes in as a clear favorite in spite of his recent injury woes which made him retire against Murray and Del Potro. Federer has always been a man to beat at ATP tour finals having won the year end tournament five times. Further, he is a defending champion this year. I expect a strong battle between Djokovic and Federer in this year's event. Nadal can never been discounted as he has simply been outplayed by Djokovic. Nadal beat Federer in French open finals and is surely a worthy contender for the title.

The real test for Djokovic will start from Australian open next year as he will have considerable points to defend over the entire year. Federer and Nadal have done it consistently in the past and are therefore hailed as all time greats of tennis. One needs to wait and see if Djokovic also has that extra will power to thump others consistently to stick to his top ranking. Early signs show that he indeed has that capability to raise to the occasion.

The arrival of Djokovic as world number one is a welcome sign for Tennis. We will be treated with some more exciting matches in ATP tour finals and Grand slams in 2012 with Djokovic-Federer-Nadal trio trying to outperform each other. Murray might also spring a few surprises if he plays up to his full capacity. Even though I am a Federer fan, my heart says that Djokovic will most probably keep others at bay to continue his reign at the top in 2012 as well.

Sunday, July 31, 2011

IIT Bombay Diaries - 1

I recently defended my PhD thesis and I would be leaving IIT Bombay after a long stretch of 7 years. As I am spending last few days at IIT Bombay, I plan to write a series of blogs about great as well as not-so-great memories over the past 7 years.  To start with, I list some of the things I would definitely miss when I leave IIT Bombay for good.

  1. Friends at IITB - PD, RamP, Swana, Dotto, Debu, Srini, etc.
  2. Unlimited high-speed Internet and file sharing
  3. Mumbai rains
  4. Powai lake view from my room (A-505, Hostel 12)
  5. Watching cricket and tennis with the H-12 gang
  6. Roaming around the campus with T-shirt and shorts without taking bath
  7. Traveling by tum-tum unlimited number of times a day
  8. Gulmohar, Laxmi and Thambi restaurants
  9. Buying and reading a large number of books
  10. Printouts of e-books from H-12 shop at reduced rates
  11. Pleasant students in and around the hostels :)
  12. World cup matches in the convo hall
  13. PAFs at OAT
  14. TT with RamP
  15. More to come ...

Sunday, May 01, 2011

KO - Movie Review

I must first thank my nephew Raghavan who propelled me to watch this Tamil movie a couple of days back. Apart from the movie, I enjoyed the newly renovated Pandiyan cinemas in my town Kariakkudi. It has dts surround sound and seating as good as any multiplex. A fight sequence involving Suriya and Anushka in the recently released movie, "Singam" (Ajay Devgan is remaking it in Hindi.), was shot at Pandiyan cinemas. It was a nice little trip with ever charming Raghavan since we had stormed some key locations in Bengalooru 3 years back.

KO (meaning King) is a realistic take on the present day politics. What makes it very relevant is that it is centered around the Tamilnadu assembly elections which was held a couple of days back. Ashwin (Jiiva) is a photo journalist who likes to do adventures to expose both the CM (Prakash Raj) and the opposition leader (Kota Srinivasa Rao) before the elections. There is another guy called Vasanthan (Ajmal) who heads the elite group of young guys who also pitches in the fray for the elections. Ashwin also finds time to romance his colleagues in the office - Karthika and Piya. Jiiva's paper contributes to the rise of Vasanthan and fall of the other 2 major parties. What transpires next is told as an edge of the seat thriller.

KV Anand is an intelligent film maker which was evident from his first film, "Kana Kanden", where he portrayed the realistic view of irregularities pertaining to academic research and PhD in India. In this movie, he explores the power of the media and how it can impact the political scenario in a very interesting manner. The camera by Richard captures the actions in a stunning way. Some of the fights and chases have been choreographed very well. Happenings of recent politics such as cash for votes, invading newspaper office, etc. are depicted well. KO is a visual treat with a thrilling screenplay.

Jiiva and Ajmal are the real stars of the movie with power packed performances without any punch lines. Jiiva fits the role of a photo journalist extremely well. Ajmal is a highly underrated actor with great talent. Karthika (daughter of actress Radha) makes a solid debut with the natural portrayal of a journalist. Piya overacts but is okay. Prakash Raj and Kota evoke laughter whenever they come on scene. 

Music is good, with "Ennamo Edho" song being a great hit from Harris. Some other duets could have been avoided which pop up arbitrarily. A few other songs remind some of the earlier songs of Harris and Yuvan. Re-recording is perfect, though. The movie does not have any major comedians, which is a major plus as the comedy would have lead to digression from the main plot.

KO is a must watch movie for those who want to see the dirty politics prevalent in Taminadu through the eyes of a journalist. It is an irony that Karunandhi's grandson Udhayanidhi Stalin is distributing this movie and the movie is publicized widely in Kalaignar TV (caught in a corruption scandal following 2G scam). It seems politicians like publicity whether they are being admired or being laughed at.