Grouping adjacent cells by given number

Discussion created by ecogeofor on Jun 16, 2014
Latest reply on Jun 17, 2014 by ecogeofor
Hello everybody,

we have a vector polygon made by 1'206'198 (500x500m) cells.

We need to make groups of 9 adjacent cells (3x3). The selected cells must belong to one and only one group.

A complication is that our grid is not regular but it is a bit distorted in order to account for the sferical and irregular terrestial surface.

Is ther any tool or proven procedure to achieve such a result?

Thanks in advance!