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Optical Disk Scanner To Cope With Media Obsolescence

Use a high resolution scanner to read the image of an optical disk into memory in one pass
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This is both a hardware/software combination (but most users will have a scanner already, and a computer to run the application on).

The idea is not really practical nor meant for use today, but rather in the near future. I think it’ll be one of those inevitable solutions that will pop up when the need arises.

It came about when I was burning a DVD of some video of my son, and wondered if he’d have a problem finding something to play it on in the future, when DVDs are as ancient as my pile of Super8 reels (that I have no way of playing).

Basically, what it does is scans an image at sufficiently high quality, of whatever optical medium you need to read (like CD, DVD, FMD etc.) into memory to be interperated by software. Think of the software as something like OCR, but in this case it’s designed to reconstruct the files written on an optical disk by reading the zero/one reflections from the scanner image.

So… it’s 2025 and your kid wants to show off his primitive low resolution baby videos to his buddies around the world: He pops the DVD onto his scanner, and his computer determines the type of disk, the data contained on it, and the appropriate codec (or it quickly invents its own based on an analysis of the data), then plays it or converts it into a modern file type.

TIB, Apr 05 2004

MySoulWander's (funny name!) link as a link http://www.elpj.com/
no charge for this service [po, Oct 04 2004]

Digital Needle http://www.cs.huji.ac.il/~springer/
Produces wav files from scanning records. [NoOneYouKnow, Feb 23 2006]

Analog Needle http://www.retrothing.com/audio_things/
Records sounds by physically scratching optical disks. Half way down. [spidermother, Feb 23 2006]

Optical mouse used as scanner http://sprite.stude.../projects/mouseeye/
For [maisere]. Requires some hardware modification. [spidermother, Mar 05 2006]

CD Detonator CD_20Detonator
[Aq_Bi, Mar 06 2006]

[link]






       Like it. Most scanners nowerdays are cheap and super high resolution, so its only a matter of time before we get ones that can see better than we can. DVDs are a bit of a problem because they are basically CDs with layers (the laser is focused at different levels to read the different levels - imagine putting lots of cds on top of each other, same thing). I actually had the same idea for records, where it was scanned rather than read with a needle, to prevent damage.
miasere, Apr 05 2004
  

       TIB just regularly bring the data forward into a new format. should avoid the problem and add to the kids fun, in the ooh look at what this was first stored on. look at old tape recorder tapes compared to CD's.
engineer1, Apr 05 2004
  

       Miasere: You might want to check out this site: www.elpj.com To archive your old LPs
MySoulWanders, Apr 05 2004
  

       If you try to scan a barcode an an image--even a 2D barcode--the space required to store the scan will have to be orders of magnitude greater than the amount of information contained in the barcode, if the barcode data is to be reconstructed usably. The situation with optical disks would likely be even worse.
supercat, Apr 05 2004
  

       sadly, cd, dvd & similar media degrade so fast that they're really not long-term storage. best to keep converting upwards.
allterrainbrain, Feb 23 2006
  

       A similar concept is to digitize your records using a flatbed scanner. I will provide a link to one person's early attempt. Unfortunately, even to scan an LP, which has VERY low information density compared to a DVD, the required is enormous. [allterrainbrain], I believe what you say about media degrading is true of the writeable media, but not the commercially mass produced media.
NoOneYouKnow, Feb 23 2006
  

       It's a good idea, but may need a laser based scanner. The scale of pits and tracks on optical disks is about the wavelength of visible light - that's why they act as a diffraction grating and produce rainbows. That means that a light microscope - and therefore a conventional scanner - is unlikely to be able to resolve the pits well enough to recover the data. Especially given the interference between the grid-like array of scanner pixels and the spiral distribution of disc pits.   

       You could improve the resolution by using shorter wavelength light, but then it wouldn't match the wavelength at which the dye reflects best. And pressed (rather that burned) discs rely on interference caused by the slight depression of the pits, so they need a laser (monochrome coherent light).   

       A scanner for optical disks would involve rotating the disk while shining a highly focussed laser on the track, and reading the bits sequentially in the reflected light - and that's well baked ;-). I'm not quite saying your method is impossible, just highly improbable.   

       [Maisare] There's a group doing what you suggest with records - scanning them then using image and sound DSP. Different from device in MSW's link, which plays records optically in real time.   

       After reading several pages turned up by googling "CD lifespan", I agree that optical discs should not be regarded as permanent. My advice:
- like [engineer1] and [alterrainbrain] said.
- keep burned disks in a cool dark place (light and heat degrade the dyes).
- use a slower write speed - there's some (anecdotal) evidence that this increases lifespan.
- develop a relaxed attitude towards permanence and change.
spidermother, Feb 23 2006
  

       Only just checked elpj.com and gaped at the price tag. I recently bought a £20 wireless laser mouse. Presumably it would be possible to mount the mouse above the disk and use that to read the tracks.
miasere, Feb 23 2006
  

       //laser mouse// It could be fitted with little wheels to follow the groove on its own. With 4 times spin and real-time playback it would make appropriate squeaking sounds.
spidermother, Feb 23 2006
  

       I like it a lot, and I think that the idea is entirely plausible.
angrygoatface, Feb 23 2006
  

       Why not just will a DVD-ROM drive to your son? Or, if you're really worried--an entire computer, monitor, and speakers (with printed instructions of course--wait, what if they don't speak English in the future? ...   

       ad nauseam   

       The actual solutions to these long-term storage problems is upgrading. Just instruct your son to copy his DVDs to his computer, and re-burn them to Blu-Ray, then Unbelievable TruVision when that comes along, et cetera. It's not as if all the DVD drives in the world will disappear once it becomes The Future. While you may not be able to play your Super8s, someone can. The same will true of DVDs, CDs, and pretty much every format.   

       For this scanner to be useful, it would have to be pretty specialized. The previous annos imply that more than one scanning method would be required. This seems to be "killing a mosquito with a cannon".
Acme, Mar 06 2006
  
      
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