i have installed opencv 3.0 and build the samples but i get the following error when trying to execute a sample :
(process:3201): Gtk-WARNING **: Locale not supported by C library. Using the fallback 'C' locale.
(result:3201): Gtk-WARNING **: cannot open display:
i have tried the same example in opencv 2.4.10 and it worked very well so i don't know if this problem is related to opencv or to ubuntu thanks for your help :)