Re: Maemo and Computational Photography
 

A simpler requirement is to push the album art into the media library. Simple crop and resize, then allows you to add to media library.

Or photograph a face and push to the contacts database, again simple crop and resize.

How about photograph a business card, character recognition and create contact

Mike C

Re: Maemo and Computational Photography
 

That one is actually already being worked on by Joaquim Rocha:
http://www.joaquimrocha.com/2009/08/...-in-fremantle/
(scroll down to the comments)

Like the other two ideas though.

Re: Maemo and Computational Photography
 

Games and sports lend themselves to computational photography.

- Photograph a scrabble board with your pieces in front of it, and the N900 works out the best move

- Photograph a chess board after each move, and the N900 produces a standard-format text file documenting the game

- Photograph a bridge hand and the N900 displays the heuristics that you normally work out in your head (high card points, number of losers, etc)

- Sports training: video yourself running and the N900 overlays a golden line showing your gait movement (by tracing out the movement of the knees, feet, hips, and arms)

- Party game: photograph each participant, then the N900 blends pairs of faces. The participant who can guess which two people made up each photo, wins!

- Movement counter, to count any kind of repetitive movement (e.g. number of gym workout moves). Just start the video camera, do one sample move, and let the N900 keep track of how many more you do.

- Accuracy detector. Touch the target area on the N900 screen, then shoot your arrows (or throw your darts, or whatever) and the N900 accumulates stats on how close you got.

And some non-game ideas:

- Weather statistics: photograph the sky, and get a figure for the percentage cloud cover. (Can you photograph the sun without burning out the camera sensor?)

- Height measurer: photograph someone in front of any object of known height, and the N900 tells you how tall that person is. Actually this can be a general "measuring" application.

- When you've forgotten the name of someone who you've met before, just surreptitiously photograph them. The N900 matches them against your previous photos, and displays their name.

- For journalists: photograph a scene, and the N900 tells you how many people are in the scene. I was always amused at the London anti-war rallies, that the ratio between the crowd size as estimated by the press and the police was at least 10:1, and often much more.

- Photograph a windsock to get a readout of the wind speed; photograph a weathervane to get a readout of the wind direction

- Car parking assistant. Your passenger gets out and points the video camera at the parking space. A voice synthesizer on the N900 says "back a bit, straighten out, forward, slightly right, stop".

- Product locator. Don't you just hate it when your supermarket rearranges the shelves and you can't find the olives anymore? Just photograph your old jar of olives at home, then walk up and down the aisles at the supermarket until the camera beeps to say that it has found the olives.

Regards,
Roger

Re: Maemo and Computational Photography
 

@eiffel

Wow... just wow!

}:^o~

Re: Maemo and Computational Photography
 

A lot of the applications that you guys describe are in fact not considered computational photography. For example, recognizing street signs or the pieces on a chess board are computer vision applications, not computational photography. Computational photography refers to image acquisition methods which combine camera(s) and computation, the output is a photograph (in contrast to computer vision, where a computer tries to understand an image and for example outputs the positions of pieces on a chess board).

I have some neat ideas for computational photography on the N900 but I'm not yet sure if they are feasible (the N900 does not have a lot of computing power when talking about state of the art image processing).

For a computer vision application, it would be cool to have an application that recognizes URLs in images and makes them "clickable". For example, if you have a magazine with a URL in it you can you take a picture and open the URL in the browser. It would be even better to do this for video in real time, not just images.

Re: Maemo and Computational Photography
 

There is an app called fotoxx that should be portable to the N900 that has a lot of nifty effects including HDR and panorama / autostitch.

Re: Maemo and Computational Photography
 

@pinish,

Excellent point. I think that all of these ideas including the computer-vision ideas could still fit well into an all incompassing framework. I have begun to spec some data-structures, as well as do some general research. I don't have a ton of time, however, so it'll be a slow process at best. However, hearing potential applications helps in determining weather the spec I have in mind will fit the bill.

Great idea, by the by! Keep em' coming!

}:^)~

Re: Maemo and Computational Photography
 

@pinsh: I accept your point about the terminology.

An interesting computational photography application would be to capture "photo-finish" images like this one:
http://www.sportingworld.co.uk/cgi-b...009photofinish

These are not regular photographs, because each vertical column of pixels is taken at a different time. You can produce them like this:

• Keep a video camera pointed at the finish line
• From every frame, extract the column of pixels that covers the finish line
• Assemble these columns of pixels into a rectangle

The final result is a "photo" that shows exactly when each runner crossed the finish line, and which part of their body was the first to cross.

Regards,
Roger

Re: Maemo and Computational Photography
 

We did something similar with Elphel cameras that used 2048x2 pixel frames and FPGA support - http://wiki.elphel.com/index.php?title=Photo-finish. The result frame rate (or actually double-line rate) was more than 3000/sec.

Re: Maemo and Computational Photography
 

I'd be excited to have some computational photography and computer vision on the N900.

here are some more ideas:

* photo-watchdog:
many industrial cameras can be configured to read out
a subset of their sensor with much higher framerate.
If that's possible on the N900 camera,
an application could watch a selected region (e.g. finish line)
for a change with very high fps and take a picture or start
video recording as soon as something changes.

* Camera-shake image deblurring:
might be to computationally demanding for the CPU
but the EXIF could at least contain all acceleration sensor data for later postprocessing

* more intelligent Autofocus modi (like professional DSLRs)
with software AF points

* online Face, cow and car detection (CVs love that! ;-)

* fast object localisation: specify some target images (e.g. one sock) and get alerted when and where something matches,
see e.g. http://www.kyb.mpg.de/publications/a...MI_[0].pdf

* live-preview as desktop background?

for the user experience: if some algorithm is too slow, it should subsample the video stream and indicate the fps in the preview.