Re: [algogeeks] Image Based Problem (Google)
OK :) On Sat, Jul 16, 2011 at 2:32 AM, Divye Kapoor wrote: > @Sagar: You misunderstand my concern. > > When I say hash collisions, I mean: > Consider 2 very different images X and Y - both have the same hash value H. > Such X and Y will always exist because you're mapping a larger > informational space to a smaller one (by pigeonhole principle in a sense). > > Without accessing the pixels in X and Y, how can you distinguish between > the two based solely on the value H? > > My proposition is that the best way to handle this problem is to store a > lossless compression of the bits of the image. Hashing will never solve this > problem in its entirety. Alternatively, relax the constraints of the problem > to allow lossy compression techniques or to include a probability of error > in the output. > > --- > DK > http://twitter.com/divyekapoor > http://www.divye.in > > -- > You received this message because you are subscribed to the Google Groups > "Algorithm Geeks" group. > To post to this group, send email to algogeeks@googlegroups.com. > To unsubscribe from this group, send email to > algogeeks+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/algogeeks?hl=en. > -- **Regards SAGAR PAREEK COMPUTER SCIENCE AND ENGINEERING NIT ALLAHABAD -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
[algogeeks] Image Based Problem (Google)
@Sagar: You misunderstand my concern. When I say hash collisions, I mean: Consider 2 very different images X and Y - both have the same hash value H. Such X and Y will always exist because you're mapping a larger informational space to a smaller one (by pigeonhole principle in a sense). Without accessing the pixels in X and Y, how can you distinguish between the two based solely on the value H? My proposition is that the best way to handle this problem is to store a lossless compression of the bits of the image. Hashing will never solve this problem in its entirety. Alternatively, relax the constraints of the problem to allow lossy compression techniques or to include a probability of error in the output. --- DK http://twitter.com/divyekapoor http://www.divye.in -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
[algogeeks] Image based Problem (Google)
Given 1000 million x 1000 million image, What information of this image to be stored such that you can find the locations when the given image has modi cations -- Regards, Navneet -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
