Le 24/11/2014 13:32, Jonas Öberg a écrit :
Hi Adrien,
Hi Jonas,
[...]
Thank you for your email. This is very interesting to learn about your project! I think you are targeting a big issue of photographers.
While we currently have the full ~22M images from Wikimedia Commons in our database, we're still ironing out the kinks of the system and making some additional improvements. If you think that we should consider ORB instead of or in addition to our current algorithms, we'd love to give that a try, and it'd obviously be very interesting if we could end up having compatible signatures compared to your database.
Your hash approach uses very small signatures, which can be quickly transmitted over a network and searched. Using the "visual word" approach I use in Pastec would enable the matching of modified images but would also require a lot more resources. Thus, while your hash is 256 bits long, an image signature in the Pastec index is approximately 8 KB. Similarly, I guess that the search complexity of your hash approach is o(1) while in Pastec this is much more complicated: first "tf-idf" ranking and then two geometrical rerankings... Finally, extracting ORB features is, I think, not something that could be done quickly in Javascript.
So my conclusion would be that, if you are fine with not matching modified images, ORB features will not be useful for your project. :-)
Best regards,