Words from Afterdark

Australia

2010-12-31T19:31:00.000+01:00

Finally! After too much time sitting on my disk, I decided to select the nicest photos from my trip to Australia in Autumn 2009.

Einsiedeln - White Christmas

2010-12-27T21:43:00.000+01:00

An advantage of living here is that I actually get to enjoy a snowy Christmas. R and I went to Einsiedeln for a romantic weekend including a light hike on snowed landscapes. It was gorgeous!

Check out the photo album:

2010-12-26-Einsiedeln

Japan in Winter

2009-02-22T02:19:00.002+01:00

Once again I was lucky to be able to go to Japan for some tourism and to meet some friends. This time, in Winter. I had never been there in Winter and was excited to see how things would look like. Also, to keep on with the cold&snow theme, I went to Hokkaido for the first time, and I stayed in little villages instead of nice cities. I also spent some days in Korea to visit some friends in and near Seoul. Here are some pictures - click on any picture to enlarge it.

A Korean ancient musical instrument. The pieces are stones. Contrary to typical Western instruments, different tones are obtained by the stones having different thicknesses, not different sizes.

Haenggung, a palace in Suwon, and Changdeokgung, another palace in Seoul:

Sapporo (Hokkaido); the Sapporo Snow Festival:



Otaru (Hokkaido), and its snow festival too:



Around Kawayuonsen (Hokkaido): From the train on the way there; geese enjoying the hotel's hot water source in the otherwise-frozen lake; town of Kawayuonsen; surroundings:

Lake Oonuma (Hokkaido):

Gassho-zukuri houses in the town of Shirakawa-go, and in the open-air museum in Takayama. Bridge in Shirakawa-go. The whole town of Shirakawa-go is a UNESCO World Heritage site, but some of those houses are hostels and you can actually spend the night there!



Old-style houses in Takayama:

On a Cessna in Central Switzerland

2008-11-01T20:11:00.002+01:00

I recently hosted two American Servas members who had just spent some days with a man who is a pilot as hobby. He invited us all to a short trip to Zentralschweiz on his club's Cessna.

Klöntal

2008-10-05T19:57:00.002+02:00

It's been a long time that I didn't post anything. On the one hand, I've been too lazy to post about some of my short vacations. On the other hand, I've been saving vacation time for a bigger vacation early next year. But the sights today were too nice to miss! My first time in Klöntal.

Vaca al sol, vaca a l'ombra

Klöntalersee, de tots els costats

More Japan in Spring

2008-05-25T22:37:00.002+02:00

From a short trip on May 2008: The Golden Pavillion in Kyoto, a sumo tournament in Tokyo, the night skyline from Shibuya's Cerulean Tower.

Flumserberg

2008-01-27T02:10:00.002+01:00

My first time at Flumserberg, with some (mostly) Japanese friends.

Winter in Zürich

2008-01-19T22:59:00.004+01:00

Some pictures of the lake by Luzern

The city of Zürich from Bellevue, the little Üetliberg, and the Real Mountain View

Thailand

2007-12-16T00:43:00.002+01:00

These were two nice weeks in Thailand.

I just came back from two weeks' holidays in Thailand, where I could enjoy a weather quite unlike that at home. You will find even more pictures here.

I started with a few days in Bangkok. There, some friends took me around the city, which is very helpful in such foreign and --to an unexperienced visitor like me-- confusing country. Wat Phra Kaeo (a large and very colorful temple), a trip along the Chao Phraya river on a bus-boat, the Vinmanmek mansion --made all of teak wood, without any metal nail--, Chinatown, Wat Pho, and so much more. Of course, Thai food for every meal! We also went on a one-day trip to Ayutthaya, one of the old capitals; it was amazing to walk around the ruins of ancient temples.

Then I spent some days in Chiang Mai. This is a much smaller city than Bangkok, and much easier for the visitor. You can walk across the city center by foot, and this city center is square and enclosed in a moat , which makes orientation simpler. This also used to be a capital city, and because of this it has many wonderful temples --more than Bangkok, it is said. I had a made-for-tourist version of a "kantoke" dinner, a particular meal eaten, as is traditional, on the floor, with a show of traditional dance.

And finally, I stayed some days in Phuket . This is an island where people go to sunbathe. I'm not the kind of person that enjoys much going on vacation just to do this, but I thought that this time I could try to strike a balance --some days visiting in Bangkok and Chiang Mai, and some days relaxing in Phuket . But Phuket is a strange place. In Kata, where I stayed, every third shop is a tailor. And it's absolutely full of Swedes and Finns! I could also do some snorkelling and I saw beatifully-colored fish that I had only seen in aquariums before (not really the gray Mediterranean!).
And on the very last day, we were treated to an excellent dance show in a commercial center.

Stockholm

2007-11-04T23:07:00.002+01:00

is gorgeous in Autumn.

Sigtuna

Djursholm

Djurgården and around

Gamla Stan

Södermalm (where, it seems, it gets so cold in Winter that they dress traffic light poles with wool sweaters)

Other areas in Stockholm

Barcelona and Llançà

2007-07-31T01:04:00.003+02:00

Some pictures from this July's visit to Barcelona and Llançà. Click here to see more pictures.

Japan in Spring

2007-05-20T20:25:00.002+02:00

My second visit to Japan, this time in Spring. As in my Summer visit, I had a wonderful time, getting to meet old friends and new acquaintances, eating delicious food, and discovering interesting places. If you want to see what I saw, have a look at my Japan travel gallery, or at the sections for Northern Honshu, Kinki, Kanto, and Tokyo.

One-day trip to Titlis

2007-05-20T20:04:00.002+02:00

In mid-April two friends and I took the train to mount Titlis. It's so comfortable to climb a mountain with cable cars, without the least effort!

Sechseläuten

2007-05-20T19:52:00.002+02:00

Sechseläuten, in mid-April, is a traditional celebration in Zürich. In Winter, it was costumary that work would stop at sunset. As days grew longer in Spring and Summer, this would of course be too late, so work would stop when church clocks would strike six. Sechseläuten (the call of six) was the day in which people would switch from "Winter work days" to "Summer work days" (the holiday is now celebrated one month later than the original day).

For this celebration, the city guilds ---societies which still exist, and whose membership is largely transmitted from parents to children--- parade through the streets. At the end of the parade, a snowman (not made of actual snow) named Böögg is set to fire -- it is said that the longer it takes for its firework-laden head to explode, the colder the next Summer will be.

Paris

2007-03-30T01:25:00.002+02:00

This March I went to Paris for a few days to meet old friends and revisit the city. It's so different when you are a tourist! You can see some pictures in my travel page. Do have a look!

Basel

2007-03-29T00:18:00.002+02:00

Un cap de setmana fantàsticament asolellat al mig de l'hivern. Basilea estava preciosa! Un munt de gent passejant-se a la vora del Rin, les terrasses dels cafès i restaurants plenes a vessar. Amb la Sílvia i en Jaume, fins i tot vam posar-nos morenos.

Obersaxen

2007-03-28T00:48:00.002+02:00

Algunes fotos de la sortida a la neu del cap de setmana passat. Un cop més, gràcies per l'organització, i fins a la propera!

Courmayeur

2007-02-03T23:30:00.002+01:00

Some pictures from a trip to Courmayeur in the Aosta valley, and the Montblanc cable car.

New York

2006-12-02T05:41:00.002+01:00

And after San Francisco, it's turn for New York! Just a first glimpse of some skyscrapers before my main touristy weekend.

San Francisco 2

2006-12-02T05:35:00.002+01:00

Here is a selection of the pictures I took in San Francisco on my last two weekends there. There's a lucky starfish, the crookedest street in the world, Mission Dolores, some Haight-Ashbury pictures, and the Transamerica Pyramid building.

San Francisco

2006-11-14T07:46:00.002+01:00

Last weekend I went to San Francisco with some friends. It's quite a change from Mountain View! We started the visit on the Golden Gate Bridge and then went on to Chinatown. By bus and cable car! Although the public transportation system is a bit messy, I felt a bit of nostalgy for Zürich's trämli. And they have the whole set: bus, tramway, trolley, and, of course, San Francisco's well-known cable cars --with the same exterior design as a Barcelona Blue Tram!

Sopar octubre 2006

2006-10-17T02:00:00.002+02:00

El sopar de la colla de catalans d'octubre 2006 el vam fer a casa meva. Aquí en teniu algunes fotos. Cliqueu-hi per a engrandir-les!

"Castellers" - human towers

2006-09-16T22:40:00.002+02:00

Today at Bürkliplatz we had a show of "castellers", the traditional Catalan "sport" of making human towers. The Catalan club in Zürich had managed to get the middle-tier Arboç team (Minyons de l'Arboç) to come for a show to celebrate the national holiday of last weekend. (Click on a picture to see a larger version). They didn't take risks ---there were not enough locals helping build a strong first floor, and they had not been able to rest after their 16-hour bus trip--- but we got some nice castles: If I recall correctly, one 4-floor welcome pillar, one 6-floor 2-wide tower, one 6-floor 4-wide tower with needle inside, two without needle, and a dual pillar (no picture -- I was helping build the first floor!). No fallen towers!

Here's a video of a 6-floor 4-wide tower (AVI, 31Mbyte).

4-floor welcome pillar	The team during a break.
Fearless little girl that climbs to the top.	6-floor 4-wide tower with needle inside.
A colleague gets inspired.	Afterwards.

Cylindrical eggs!

2006-09-13T00:38:00.002+02:00

What kind of egg would robotic chicken lay? During lunch break today we decided we needed an answer. Well, that's not quite how it started. One of us mentioned egg rolls, something which could be sliced, each slice looking like a real hard-boiled egg slice. Another person confirmed he had read about it. The rest wouldn't believe it. We explored --with Google of course-- the underworld of egg manufacturing and egg produce, and here are some answers: Nutregg (with picture of egg cylinder!), a synthetic image of egg-based extrusions, a definition of "egg roll", some websites confirming the existence of cylindrical eggs (you got an egg problem? We got Egg Solutions!). And finally, the wonderful Ovobel, which, though staying clear of linearly-enhanced avian products, offers an amazing range of egg processing equipment, reaching flows of 1.1Megg/day (egg breaking), 691kegg/day (egg hardboiling - 0.2 Gegg/year!) and 120komelette/day.

Jungfraujoch

2006-08-12T21:38:00.002+02:00

Some pictures taken during a train trip to the Jungfraujoch with my mother last week. After going through a tunnel excavated into the Eiger, we reach the highest train station in Europe, at over 3300m. From the station we can access what initially was a research facility at the top of the Jungfrau, which was used as the villain's HQ in one James Bond film. Click on the "more" link to see all the thumbnails, and click on a thumbnail to enlarge.

Zürich Street Parade 2006

2006-08-12T20:55:00.002+02:00

Today is Zürich's Street Parade!

The very famous whole-city open-air day-time techno party attracts hundreds of thousands of young and not-so-young people from Europe and all over the world. And I was in Zürich, so I had to take a look.

Well, it wasn't what I expected. The Street Parade is composed of an actual parade, where vehicles move slowly along and the crowds cheer them, some scenes where DJs play music and people dance, and many many techno parties during the night. I thought that the parade would be more carnival-like, where each vehicle would somehow be themed in a different way, and that it would be a very lively and cheerful event. It turned out that most of the vehicles were just a moving disco, with some people on it dancing but must just standing there, ultra-powerful speaker systems, and on some of them, a DJ. Quite boring on that side.

The good part was the crowds. A great many many people, something unusual for Zürich, all dressed in top dance fashion. Some drag queens, many scantily clad females. What I liked best were themed couples, a boyfriend and a girlfriend dressed in the same style.

Click on a picture to see a larger version.

Luzern

2006-08-01T21:31:00.002+02:00

Swiss National Day, and my first tourist visit to a city out of Zürich since I arrived. Just an our away from Zürich by train, this city by a beautiful lake has a small old town with buildings with frescoed walls, medieval wooden bridges, and a solid stone wall.

(Click on a picture to see a larger version)

"In Lucerne University, the heating doesn't work in winter. Study in Lucerne."

The very straight KKL, Lucerne's art and congress center, by the architect Jean Nouvel.

The mount Pilatus next to Lucerne.

A golden notefish.

Casal català de Zürich

2006-07-16T23:06:00.002+02:00

Dimecres passat va ser el primer sopar dels joves del casal català de Zürich des de que sóc aquí i tinc prou temps lliure per ocupar-me d'aquestes coses. I és clar, vaig anar-hi. Una gent molt maca. Una gran majoria havien vingut a Suïssa seguint el nòvio o la nòvia. Sóc raro per tenir una altra història? El temps i l'hivern dirà si la feina és una bona raó per venir aquí. De moment s'anuncia un espectacle de castellers a a Bürkliplatz el setembre --ja penjaré la notícia quan en tingui els detalls-- i un nou local del casal al costat del llac. Potser la propera trobada no serà un sopar sinó una banyada? Hi seguiré en contacte.

From the Uetliberg

2006-07-05T23:22:00.002+02:00

All these posts talking about my flat my flat my flat. So where is it? I took a train to the top of the Uetliberg and took this picture to show you.

My first guest

2006-07-05T23:02:00.002+02:00

My new flat is little by little becoming a real flat, with a bed, dining table, dishes, towels, ... And people. After a record Ikea furniture mounting spree --the bed absolutely had to be ready for that night's sleep!--, this weekend I have received my first guest, Vera. She has been travelling a lot in south-east Asia, and lately she's been a bit in Europe. Don't miss her wonderful blog Luzhou Express!

The poor girl had to sleep in a room full of unmounted furniture and unopened cardboard boxes (but I did finish mounting her bed before her first night here), and endure the fact that, since my fridge was (and is) broken, I couldn't store anything more advanced than bread and pasta. So that's what we ate. After listening to her interesting stories about her travels and travails (sorry) in Thailand, I guess that's not so bad, after all. See you Vera!

I couldn't resist

2006-06-18T15:47:00.002+02:00

Sorry, after so many weeks of blogging from misconfigured, outdated, user-unfriendly, Internet cafés, I'm so happy of being able to use my own computer that I couldn't resist posting some more pictures.

New flat

2006-06-18T15:43:00.002+02:00

I've got a flat! Yes, after some weeks of search --and, it appears, quite sooner than I should have expected for Zürich-- I've found a beautiful flat near the lake. It was a bit daunting at the beginning, such an empty space! But I feel a certainly childish thrill at the prospect of filling all this up. Perhaps it's the idea of changing a dead space into a home? But I'm being silly. While I wait for the furniture to arrive, enjoy the view of my flat messy full of boxes from Barcelona.

Tourist in Zürich

2006-06-01T13:32:00.002+02:00

I've spent the last few days visiting the city. Getting to know each neighborhood, to decide where I want to live. Knowing where the important shops are. The nice areas to have a walk.

I've discovered a couple of funny things of this city. First, there are sheep in it. No, not people, real sheep! Look at the picture. This was not in the countryside near Zürich. It was in a park inside the city, near Irchel. I promise!
Second, in the banking district there is a branch of UBS bank with hundreds of screens in the windows, displaying share prices and stockmarket graphs, and passers-by, going back home from work in the evening, check them. Is that just a publicity stunt by UBS, or are people really checking their finances? I'll have to ask.

Some more tourist pictures. First, a view of Zürich's "port" and lake, with high snow-capped mountains in the background --and that's at the end of May--, and one of an appetizing lawn in Zürichhorn, with people enjoying the good weather. If I'm lucky, I'll get a flat real close to this :-)
And, to end, some pictures taken from Uetliberg. That's a small mountain next to the city. I tried to climb it last weekend, but it started to rain and I decided to go back before I had reached the top. But with better weather, I'll try again.

First weekend in Zürich

2006-05-22T17:55:00.002+02:00

My last post wasn't very inspired, sorry. I was quite tired after my first week settling down here, and also, as you have guessed, the post was just an excuse to show you some pictures of this place. Being tired, I decided I would use Sunday to sleep as much as possible --after all, everything is closed here on Sunday, so there's nothing to do, right? Right? Well, at 09:00 Sunday an enormous noise woke me up. Church bells tolling everywhere! I didn't expect this to happen here. But since I had gone to sleep so late, it wasn't time to wake up yet. So back to sleep, after five minutes of bells. Then, at 12:00, there come the bells again! This can't be, I thought Switzerland was the country of peace and quiet. Can't you have a good day's rest on a Sunday? Well, too bad, time to wake up. Then... I noticed we were having a wonderful weather! So there was something to do this Sunday after all. I went to the lake, and spent a lot of time sunbathing and reading. The weather was as good as at home! I hope we'll have such a clear sky next weekend.

First days in Zürich

2006-05-21T01:48:00.002+02:00

I'm there! Finally! After much preparation and some wonderful holidays in Barcelona, I arrived at Zürich last Tuesday. Since I won't start working until June, I have a few weeks of vacation, which I'm using to get to know the city, find a flat, and do some paperwork. I've finally found the time to update my blog and so let all my friends know about the beginning of my Swiss life. First things first: this is the first picture I took: A swan enjoying the good weather in Zürich lake.

Every day, I buy a daily tram pass and move up and down the city. I want to get to know each neighborhood so I can get a flat in a place I like. But my first impressions are very good, I think I'll enjoy living here. The city is active yet not stressing, and nature is five minutes away by tram.

On sunny days --yes, I've had quite a few-- a boat trip on the lake shows gorgeous views, but even rainy days are tolerable.

Zürich inhabitants are known for their lack of a sense of humour. Of course, this is said of many other peoples. I've been so busy these days that I have not had the time to have a joke-telling session with a local, but they seem to have a funny side. Although that of the civil engineers who designed this motorway on the right may be a bit weird.

There will be many more things to tell about Zürich. But I'll have plenty of time! For the moment, allow me to finish with a typical postcard picture, and two mistery pictures --it's up to you to find out what they are!

Ja tinc .cat! - Dot-cat is here!

2006-04-25T01:21:00.002+02:00

Per fi! A partir d'ara podreu accedir a la meva web també per l'adreça http://www.rogerts.cat. Bona navegació!

At last! You can from now on reach my web site also through the dot-cat domain http://www.rogerts.cat. Happy surfing!

Life is everywhere

2006-04-25T01:14:00.002+02:00

Even after people have done their best to tame (enslave?) their environment, life manages nonetheless to pop up in the most unsuspected places. I found this poor little plant growing in a concrete underpass near Barcelona's container port.

Water flames

2006-04-20T17:53:00.002+02:00

My first post since I got back to Barcelona. I am a true tourist now. On holiday, visiting this city for the first time in some months, and here only temporarily. I spend my mornings doing paperwork and other "non-leisure" activities, and the afternoons walking around and taking pictures. But I need to hurry and rediscover this city quickly, for I will soon leave for yet somewhere else!

Chocolat chaud au matcha

2006-04-09T22:08:00.002+02:00

This is my last post from Paris! Tomorrow I'll pack and ship my computer, and I don't think I'll be going to an internet café just to update my blog. Today I went to watch "Ice Age 2", but I arrived to late and there were no seats left. So I had a walk instead. Quartier Montorgueil, Palais Royal, Pont des Arts, Rue de la Seine, Jardin du Luxembourg. Then I realised it had taken me only one hour. I must have walked really fast! This picture is from a Japanese café Iku and I went to last weekend. Tasty mixture of matcha and hot chocolate.

Reading by the Seine

2006-04-08T20:40:00.002+02:00

Today I got rid of most of my furniture. Julia's father took that which belonged to her daughter. The neighbour downstairs got a fridge and a bookshelf ---we came across her on the stairs and cold-asked her if she wanted it. Some friends will take the remaining stuff on Monday. My living room is full of boxes, and my sleeping room is so empty it makes me sad. No picture of that, it's too ugly. Instead, feel the moment of utter leisure that this man is enjoying.

La ville de l'amour

2006-04-07T00:40:00.002+02:00

Now that I've finished my PhD, I will soon be leaving Paris, the city where I've lived for the last four years, and go back home to Barcelona ---although the journey won't end there. These final days I will be revisiting my old favourite places, drowning in paperwork, having good-bye parties with friends, and posting some "Paris-themed" entries here. Look! The prettiest pigeon in Paris and the ugliest pigeon in Paris have fallen in love!

Tesi / Thèse / Thesis

2006-03-28T20:38:00.002+02:00

El part fou llarg, i tots els presents afirmen que el nen té un pes molt superior a la mitjana. Divendres passat vaig llegir la tesi! Més info aquí.

L'accouchement fût long, et tous les présents affirment que l'enfant dépassait largement le poids moyen. La thèse est soutenue!

Yes, it's true -- I've finally defended my thesis! More info here. Thanks to all that came to the defence. And now it's time for some vacation. Clear horizons.

Mochi

2006-02-16T19:19:00.002+01:00

Iku cooked mochi yesterday. Mochi are wonderful whitish, very hard, brick-shaped objects. You might be tempted to use them as construction toys, or maybe as doorstops. However, their magic happens when they are heated in an oven or grill. Then they swell and become soft and mushy, and very sticky. You can top them with cheese, nori, soy sauce or whatever, and eat them. Amazing! Also, they taste great. そ�‹ そ�‹ そ�‹...

Surrealism

2006-02-10T21:05:00.002+01:00

I have lately been involved in three strange events on the verge of the surreal. I think that the reason for that is that the world is coming to an end. More specifically, it will end on March 24th, 2006, at 14:00. If all goes well, it will start again a couple of hours later, more or less the same as before, except that I'll have one more certificate.

The first event: After my Ph.D., I'll be moving out. So, I sent a letter to the rental agency telling them that I'd leave at the end of April. It seems that the letter arrived on the 18th. And they thought that this meant that I would be leaving on April 18th. I spend half an hour on the phone explaining, in great detail, how April ends on a 30th --or at least, it is scheduled to do so this year--, that I couldn't control the date the letter reached them, and that, even if one interprets "end of April" in an approximate way, 29th or 28th would be acceptable but certainly not 18th.

The second event: A friend got the idea of asking friends for their favourite phrases in their own languages, and posting them on a paper on her door, in a dorm. She was so excited about it that she insisted on meeting me that same afternoon at my house --we were meeting two days later at a place closer to hers-- so I could write it. Email wouldn't do it. She came, carrying a sandwich, because she was so hungry. While I wrote the phrase on a piece of paper she ate the sandwich. Immediately after she left because she had another appointment.

The third event: I have to send a file to a journal. I asked them by email if I had to send a MS-Word file, or if a PDF was ok --it's easier for me. The reply: "SUBMISSIONS MUST BE IN SINGLE-COLUMN FORMAT".

Shakuhachi

2006-02-04T00:55:00.003+01:00

There was a shakuhachi concert today at the Cité Universitaire. For those that do not know, shakuhachi is a traditional Japanese flute with five holes made with a bamboo stem. While I am not a great fan of shakuhachi melodies, I find the individual sound of each note extremely beautiful. Very soothing, it reminds me of peaceful natural scenes and the passing of seasons --sure enough, all things we Westeners tend to associate with Japan.

Invitació a defensa de tesi

2006-01-30T14:19:00.002+01:00

Tinc el plaer de convidar-vos a la defensa de la meva tesi de doctorat, titulada "Classificació semi-automàtica del terreny en zona rural a partir d'imatges d'alta resolució", el divendres 24 de març del 2006, a les 14:00, a la sala Genot de l'Institut Géographique National a Saint-Mandé, prop de París, França.

La resta del missatge conté l'adreça d'on hi haurà la defensa, mapes per a arribar-hi, la composició del tribunal, i un resum de la tesi.

La defensa tindrà lloc a: Institut Géographique National; bâtiment N, salle Genot; 2-4 avenue Pasteur; 94165 Saint-Mandé; France. Cliqueu a les imatgetes per a veure mapes per arribar-hi.

El tribunal de tesi està compost de: Dr. Matthieu Cord (ENSEA), Pr. Josef Kittler (University of Surrey), Dr. Jean Louchet (INRIA), Pr. Ferran Marqués Acosta (Universitat Politècnica de Catalunya), Dr. Marc Pierrot-Deseilligny (Institut Géographique National), i Pr. Georges Stamon (Université de Paris 5).

Resum de la tesi:

Durant els darrers temps s'han esmerçat molts esforços en recerca sobre la determinació automàtica del tipus i ocupació del sol a partir d'imatges aèries i de satèl·lit en zones rurals. No obstant, les taxes d'error han estat sempre massa altes per a aplicacions industrials.

L'Institut Cartogràfic Nacional francès (Institut Géographique National, IGN) s'interessa a la classificació automàtica del terreny per tal d'accelerar la producció dels seus mapes topogràfics a gran escala. El context a l'IGN, però, és lleugerament diferent: Primer, l'IGN disposa d'imatges digitals de molt alta resolució espacial (50cm per píxel), però de baixa resolució espectral (canals vermell, verd, blau i, en alguns casos, infraroig proper), cosa que impedeix utilitzar tècniques clàssiques d'anàlisi hiperespectral. A més, disposa de dades cadastrals, que donen una indicació aproximada de la localització dels camps. Finalment, a l'IGN, guiat per consideracions pràctiques, no li interessa especialment obtenir classificacions de qualitat mitjana sobre tota la zona de treball, perquè aquesta classificació hauria de ser revisada per un fotointèrpret cosa que costaria molt de temps, sinó que prefereix una classificació de molt alta qualitat sobre només una part del terreny, i deixar als fotointèrprets la tasca de classificar manualment la resta.

En aquesta tesi de doctorat, presento un sistema complet d'anàlisi d'imatges que, a partir d'imatges digitals d'alta resolució a 3 o 4 canals (50cm, color i opcionalment infraroig proper), i utilitzant dades cadastrals, segmenta les imatges en zones agriculturalment homogènies (camps, boscs, vinyes, ...) i les classifica, indicant per a cada regió una mesura de la confiança que el sistema té en la classificació, cosa que permet de rebutjar les regions que més probablement han estat mal classificades.

El procés comença amb una segmentació jeràrquica, on s'utilitzen espais de color, paràmetres de textura, i criteris de forma adaptats al problema de segmentar zones agrícoles. Aquesta segmentació permet de registrar el cadastre sobre l'imatge, donant grans regions sovint homogènies. El procés de registració permet també d'utilitzar el sistema per a posar al dia una classificació antiga. Aleshores, cada parcel·la cadastral registrada ---o, si no es disposa de dades cadastrals, cadascuna de les regions petites obtingudes per una segmentació per watershed--- es classifica amb algorismes probabilístics de classificació per regions desenvolupats en aquesta tesi. Aquests algorismes, a diferència dels clàssics que operen píxel per píxel, no produeixen soroll sal-i-pebre, i calculen una mesura de confiança per cada regió classificada. Les regions amb baixa confiança poden rebutjar-se i fer-se classificar a mà per un fotointèrpret si l'aplicació ho demana. Aquests algorismes són supervisats, i s'han d'entrenar amb una veritat terreny feta a mà abans de la classificació.

Com a resultat obtenim una segmentació de l'imatge en regions classificades i homogènies agriculturalment, i una mesures de confiança per cada regió, que un fotointèrpret pot utilitzar per a corregir els resultats o per a concentrar el seu temps limitat en les zones amb més risc d'error.

Invitation à soutenance de thèse

2006-01-30T13:09:00.002+01:00

J'ai le plaisir de vous inviter à la soutenance de ma thèse intitulée "Classification semi-automatique du terrain en zone rurale par télédétection à haute résolution" qui aura lieu le vendredi 24 mars 2006, à 14:00, dans la salle Genot de l'Institut Géographique National, à Saint-Mandé, près de Paris.

Veuillez trouver ci-dessous une description courte de la thèse, l'adresse du lieu de la soutenance, des plans pour y arriver, la composition du jury, et un résumé long.

Cette thèse présente une chaîne d'analyse d'image qui, à partir d'images numériques à haute résolution et à trois ou quatre canaux (50cm, couleur et, dans certains cas, proche infrarouge), mais aussi en s'appuyant sur le parcellaire cadastral, rend une segmentation des images en parcelles agraires (champs, forêts, vignes, ...), et une classification de celles-ci, avec une très haute fiabilité, et attribue à chaque segment classifié une mesure qui indique la confiance que le système a en cette classification. Elle inclut une étude sur l'intérêt de la texture et les espaces de couleur pour la segmentation et la classification, deux méthodes de recalage de graphes sur une image, un modèle de probabilité novateur et ses algorithmes de classification par régions associés, et un estimateur très précis de la période et l'orientation.

La soutenance aura lieu à l'adresse suivante: Institut Géographique National; bâtiment N, salle Genot; 2-4 avenue Pasteur; 94165 Saint-Mandé; France. Veuillez cliquer sur les onglets pour voir des plans pour y arriver.

Le jury de thèse est composé de Dr. Matthieu Cord (ENSEA), Pr. Josef Kittler (University of Surrey), Dr. Jean Louchet (INRIA), Pr. Ferran Marqués Acosta (Universitat Politècnica de Catalunya), Dr. Marc Pierrot-Deseilligny (Institut Géographique National), et Pr. Georges Stamon (Université de Paris 5).

Résumé étendu:

De nombreux travaux d'analyse d'image ont été et continuent d'être menés pour tenter de déterminer automatiquement l'occupation du sol en milieu rural, mais aucun n'a encore produit de résultats assez fiables pour être exploitables dans une chaîne de production industrielle.

L'Institut Géographique National français (IGN) s'intéresse à la classification automatique du terrain pour accélérer la production de cartes topographiques à grande échelle. Le contexte à l'IGN est, cependant, différent de celui de la plupart des recherches dans la classification automatique: D'abord, on dispose d'images numériques à très haute résolution spatiale (50cm par pixel), mais ces images sont à faible résolution spectrale (canaux rouge, vert, bleu et, dans certains cas, proche-infrarouge), ce qui rend impossible l'utilisation de techniques classiques de classification de données hyperspectrales. De plus, on dispose des données cadastrales, qu'on peut utiliser pour obtenir une information grossière de la position des champs. Finalement, l'IGN n'est pas particulièrement intéressé à obtenir des classifications automatiques de qualité moyenne sur l'ensemble du territoire, classifications qui devraient être vérifiées, à grand coût en temps, par un photo-interprète. Par contre, l'IGN voudrait obtenir une classification de très haute qualité, même si c'est sur seulement une partie du territoire, car cette classification n'aurait pas à être vérifiée manuellement, et les photo-interprètes pourraient concentrer leur temps à classifier la partie restante.

Dans cette thèse, je présente une chaîne d'analyse d'image qui, à partir d'images numériques à haute résolution et à trois ou quatre canaux (50cm, couleur et, dans certains cas, proche infrarouge), mais aussi en m'appuyant sur le parcellaire cadastral, rend une segmentation des images en parcelles agraires (champs, forêts, vignes, ...), et une classification de celles-ci, avec une très haute fiabilité, et attribue à chaque segment classifié une mesure qui indique la confiance que le système a en cette classification.

Une phase initiale de segmentation hiérarchique de l'image, qui utilise un espace de couleur, des paramètres de texture, et des critères de forme adaptés à la segmentation de parcelles agraires, permet de recaler le cadastre sur l'image, produisant des régions grandes et en général homogènes. Ce recalage permet aussi d'utiliser le système pour la mise à jour de classifications anciennes. Ensuite, chacune de ces régions de cadastre recalées ---ou, si les données cadastrales ne sont pas disponibles, des petites régions issues d'une segmentation par ligne de partage des eaux--- est classifiée au moyen de nouveaux algorithmes probabilistes de classification par régions qui, à la différence des algorithmes classiques par pixels, ne produisent pas du bruit poivre-et-sel, et qui génèrent aussi une mesure de confiance pour chaque région classifiée. Les régions classifiées avec une trop faible confiance peuvent ensuite, selon les besoins de l'application, être rejetées et classifiées manuellement par des photo-interprètes. Ces algorithmes doivent être entraînés auparavant à partir d'une vérité terrain définie manuellement.

�€ la fin on obtient une segmentation de l'image en parcelles agraires homogènes, une classification de celles-ci, et des indicateurs de confiance sur chaque partie de la segmentation, ce qui permet à un photo-interprète de réaliser les corrections nécessaires et de concentrer son temps limité sur les zones qui plus vraisemblablement contiennent des erreurs.

Invitation to thesis defence

2006-01-30T12:32:00.002+01:00

I have the pleasure to invite you to the defence of my doctoral thesis "Semi-automatic rural land cover classification from high-resolution remote sensing images", which will be held on Friday, March 24th 2006, at 14:00 in the Genot hall of the Institut Géographique National, in Saint-Mandé, near Paris, France.

The rest of this entry contains a short description of this thesis, the defence site's address, maps to get there, the defence committee member list, and the long abstract.

This thesis presents a complete image analysis system which, from high-resolution 3 or 4-channel digital images (50cm, colour and optionally near infrared), and using the cadastre database, segments the images into agriculturally-homogeneous regions (fields, forests, vines, and so on), and classifies these regions, tagging each classified region with a confidence measure which indicates the system's confidence in each classification. It includes a study of the value of texture features and transformed colour spaces for segmentation and classification, two methods for registering a graph onto an image, a novel probability model and associated per-region classification algorithms, and a high-precision period and orientation estimator.

The site's address is: Institut Géographique National; bâtiment N, salle Genot; 2-4 avenue Pasteur; 94165 Saint-Mandé; France. Please click on the thumbnails to get maps to the IGN.

The defence committee's members are Dr. Matthieu Cord (ENSEA), Pr. Josef Kittler (University of Surrey), Dr. Jean Louchet (INRIA), Pr. Ferran Marqués Acosta (Universitat Politècnica de Catalunya), Dr. Marc Pierrot-Deseilligny (Institut Géographique National), and Pr. Georges Stamon (Université de Paris 5).

Long abstract:
Much research has been done on the subject of automatically determining land use and land cover in rural areas from images. However, error rates have always been too high for industrial application.

The French National Mapping Agency (Institut Géographique National, IGN), is interested in automatic land cover classification for the purpose of speeding up production of high-resolution topographic maps. The context at IGN is, however, slightly different from that at most other research into automatic land cover classification: First, very high spatial resolution digital images are available (50cm per pixel), but these images have a low spectral resolution (red, green, blue, and in some cases near-infrared channels), which precludes the use of standard hyperspectral classification techniques. Second, cadastre data is available; this data gives a very rough indication of field position. Finally, IGN's interest stems from practical goals: to reduce the amount of time spent by human photo-interpreters doing manual classifications. Therefore, IGN is not especially interested in obtaining a medium-quality land cover classification of the whole region of interest but would rather have a very high quality classification of only a portion of the terrain; the first one would have to be double-checked in full by a photo-interpreter, whereas the second one would not need further human verification, so that photo-interpreters would be able to concentrate on the remaining areas.

In this Ph.D. thesis, I present a complete image analysis system which, from high-resolution 3 or 4-channel digital images (50cm, colour and optionally near infrared), and using the cadastre database, segments the images into agriculturally-homogeneous regions (fields, forests, vines, and so on), and classifies these regions, labelling each classified region with a confidence measure which indicates the system's confidence in each classification, and which can be used to filter out regions that are more likely to have been incorrectly classified.

The process starts with a hierarchical segmentation, using a colour space, texture parameters, and shape criteria adapted to the problem of segmenting agricultural regions. This segmentation is used to register the cadastre onto the image, giving large, usually homogeneous regions. Through this registration, the system can also be used to update older classifications. Then, each of these registered cadastre regions ---or, if cadastre data is not available, small regions obtained by watershed segmentation--- is classified using novel probabilistic per-region classification algorithms which, unlike traditional per-pixel algorithms, do not produce salt-and-pepper noise, and which also output a classification confidence measure for each classified region. These classification algorithms are supervised, and need to be trained beforehand with a ground truth defined by a photo-interpreter.

As an end product we get an image segmentation into classified agriculturally-homogeneous regions, and confidence measures for each part of the segmentation, which a human photo-interpreter can use to correct these results or to concentrate limited available time into the most likely errors.

Mari/Keiko

2006-01-28T22:51:00.003+01:00

Je viens de passer quelques journées très agréables avec Mari et Keiko, de visite à Paris. Pour qu'elles puissent laisser ses impressions, je leur fais ce message. ... Merci, et j'espère que je vous reverrai bientôt!

Trees

2006-01-28T15:12:00.002+01:00

After much preparation and procrastination, I have finally gathered the strength to start my blog. The frist pots is a picture (click for full-size) of some trees taken in the Marais Poitevin, in Western France. But something's odd... what?

Disappointed? Where you expecting something more ...introductory... as a first post? Then have a look at the About page.