Hash will suggest if the image was modified or not. The question I think is about finding the exact pixels which changed compared to original one.
-- On Thu, Jul 14, 2011 at 3:50 PM, sagar pareek <sagarpar...@gmail.com> wrote: > oh common.... take HASH of the image whuch need less space compare to > original one.... > :) > > On Wed, Jul 13, 2011 at 1:01 AM, DK <divyekap...@gmail.com> wrote: > >> @Santosh: It depends on the type of the image. An image cannot be >> represented in a (lossy) compressed format using fourier or wavelet >> coefficients if we are to detect modifications that are at the pixel level. >> >> For example: No compression technique will be able to compress an image >> with pixels sampled from a perfectly random source. Hence, in the worst case >> - we will have to store each and every pixel of the image. Improvements are >> only possible if we are given that such images are rare or that the data in >> the images is compressible or that we are allowed a certain degree of pixel >> error tolerance. >> >> -- >> 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 view this discussion on the web visit >> https://groups.google.com/d/msg/algogeeks/-/LeY_7ttPal0J. >> >> 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. > -- 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.
