Domain: dheera.net
Stories and comments across the archive that link to dheera.net.
Comments · 8
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Bluring vs. blacking-out data
I guess the author of TFA didn't read
/. today. Otherwise he would have known to black-out and not just blur those images. credit: this comment from the SSN leak article earlier today. -
Author of WTF article made security mistake also
The author should have completely blacked out the SSNs rather than blur them. They are still decipherable to those that are inclined to do so. This article explains why blurring is a bad idea.
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Re:Pictures
It cannot be enhanced, but if you have some idea as to what is behind the blur, and you treat it like a hash, you can recover a remarkable amount of information:
http://dheera.net/projects/blur.php -
Re:Using what filter?
Don't tell Dr. Jones about this.
The example isn't a photo, but I don't think it's inconceivable to apply similar techniques on blurred photographs. -
Re:Using what filter?
The Japanese blur their porn, and so someone has invented a device that removes it and restores the original image. This is possible because it performs a transformation from a limited set every time and so all you need is one clean sample.
You realise that several (Japanese, I think) blurring algorithms are specifically designed to be reversible, right?
Properly designed blurring filters cannot be reversed so easily! Alternately, instead of blurring, they could just use black squares to cover stuff up. -
Locating key establishments
So now, not only Google but also the terrorists would know which key Indian establishments are located where:
Key establishment is a blurred spot!
Who knows how complete is the list of key establishments provided to google?
Also, there are techniques to get information about the real image out of blurred images. This link http://dheera.net/projects/blur.php is only about numbers but I'm sure there are other ways to get more information out of blurred images. -
fonts
any clues on how to fix these terrible fonts? (look at the address bar and the menu bar): http://dheera.net/wineie.jpg I've already installed all the MS TrueType fonts. I'd like it to actually use TT fonts for the widgets...
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Albedo and CO2 and Solar Constant
While replying to yourself is probably some form of onanism, I was wondering exactly how the difference in solar constant levels due to distance would affect temperature on earth and venus.
The answer? Not much -- it's really all down to CO2 and albedo. Without atmospheres, Earth would have a mean temperature of Earth (-12C) and Venus (-23C).
More here, and here is the key:
The atmosphere would finally stablilize at a still higher temperature and pressure after all the carbon dioxide had been driven from the rocks. In fact, we believe that if this sequence were to take place on the Earth, the resulting temperature and pressure of the atmosphere left behind would not be very different from that for present-day Venus: the atmospheric termperature would be hundreds of degrees Celsius and the pressure would be maybe 100 times greater than it is today. Thus, we believe that in the case of Venus the initial solar heating kept oceans from forming, or kept them from staying around if they did form, and the subsequent lack of rainfall and failure of plant life to evolve kept the carbon dioxide in the atmosphere rather than binding it in the rocks as is the case for the Earth; thus, Venus has an environmental disaster for an atmosphere. The sobering warning for us is obvious: we have to be extremely concerned about processes such as burning of fossil fuels in large volumes that might (we don't know for sure because the scientific questions are complex) have the potential to trigger a runaway greenhouse effect and produce on the Earth atmospheric conditions such as those found on Venus.