I’ve been reading papers lately about using image processing techniques to remove artifacts and damage from old motion picture film. Some old films are remarkably pristine, but some, like my copy of Douglas Fairbanks’ 1924 version of Thief of Bagdhad show lots of wear and tear.
I think it will be possible to write an automated system for removing many of these artifacts, so I thought I’d give it a whirl. The first baby step is to be able to read individual frames off the DVD and convert them into a canonical format. Luckily, the ffmpeg project has a pair of libraries which can read a wide variety of video formats and convert them into standard grayscale, RGB or YUV colors spaces. Tonight, I wrote a program which slurps off the first 1000 frames from a DVD .vob file, and saves them out as PGM files (grayscale only, since this film is black and white). You can see a small example on the right, or full frame version here. You can see a couple of artifacts: dust, dirt, and vertical scratches. The exposure of the title slide is also rather
This is just a baby step, but a necessary one. My next step is to scan the DVD and determine the scene breaks. I suspect I can do this simply by summing the squared differences between adjacent frames, and splitting the sequence at peaks. Once I have this, then I can begin on a scene by scene processing. I envision a system that will eliminate the film weave, uneven exposures, and vertical scratches. If I get that far, I’ll be very, very proud.
Kevin Kelly had a very nice New York Times Op-Ed piece entitled Making My Own Music, which clearly elucidates the way that I’ve come to think about copyright issues and the value of the public domain.
One small quote:
Given the benefits of digitized films, there is little question that film buffs, powered only by passion, would rush to convert the 500 to 1,000 films that fall out of copyright each year — if the copyright period is not extended.
This is an old article, written before the decision in Eldred v. Ashcroft, and unfortunately for the country (although perhaps good for the Mouse), the arbitrary and excessive extension of automatic copyright protection was held to be consitutional.
Metafilter had a link to Bob Metcalfe’s 1995 article Predicting the Internet’s catastrophic collapse and ghost sites galore in 1996 (InfoWorld). It’s always incredible to look back on historical predictions and see how they panned out.
For those of you who don’t know who Bob Metcalfe is, he is the inventor of Ethernet and founder of 3Com.
Metcalfe predicted a dot.com collapse in 1996, but despite his assertions to the contrary, companies appeared to be able to find greater fools to fund their ideas for a few more years until they were finally exhausted around 2000. Similarly, measurements have proven that web based advertising isn’t particularly effective, and the ridiculous rates for web advertising have mostly collapsed into reasoanble levels. Security is still a huge issue, but is one what we continue to ignore at our peril, hoping that the virus scanners will keep ahead of the virus writers and that we are smart enough to avoid identity theft and scams.
And of course, there is no problem finding pornography on the web.
Brace yourself folks: I think that Metcalfe was merely just ahead of his time.
Before I discovered Python, I enjoyed a brief period of experimentation with Lua. I even went so far as to use Lua to add a simple shading language to my old MTV raytracer. You could write Lua functions that would compute the results of certain shading operations. It was pretty slow, but was really quite easy to do.
Now, I’ve discovered there is a nice looking book, Programming in Lua, which you can either buy or read online. I may have to revisit Lua again.
In the decade to come, it’s clear that the Internet will face two related challenges:
- Increasing volume of spam, and
- Increasing sophistication of viruses.
These two are related because spam is being increasingly used to spread viruses, and viruses are increasingly used to subvert security measures on computers and to turn them into spam relays.
The Register reports that a hacker has produced the first PocketPC virus. Oh joy. Along with the recent discovery of cell phone viruses, we can expect an entire new generation of annoyances and irritations, if not thefts and vandalism.
I don’t mean to sound like a Luddite, but I do have some fear for the future. Our increasing reliance on the relatively weak infrastructure we’ve developed is dangerous. Depending on who you talk to, somewhere between thirty and eighty percent of the bandwidth on the web is tied up in processing spam. Many of these messages carry virus payloads. And it’s likely to get worse before it gets better.