[Qgis-developer] get mean of pixel values within defined area around current mouse position

[Otto Dassau]

Hi,

for a qgis 1.8 plugin I would like to query the mean of pixel values of a
raster layer within a defined buffer for the current mouse position (not for
an existing point layer).

For the buffer it works:

... 
feat.geometry().asPoint() 
(3.5176e+06,5.4062e+06)
buff_geom = feat.geometry().buffer(1000, 5)
buff_geom.asPolygon() [[(3.5186e+06,5.4062e+06), (3.51855e+06,5.4059e+06),
(3.51841e+06,5.40562e+06), (3.51819e+06,5.4054e+06),
(3.51791e+06,5.40525e+06), (3.5176e+06,5.4052e+06),
(3.51729e+06,5.40525e+06), (3.51701e+06,5.4054e+06),...]]

but now I try to find a solution to query the raster pixels within the
buffer zone and calculate the mean, but I don't know how and if this is
possible in QGIS 1.8 at all. I found QgsZonalStatistics, but that doesn't
work for my task.

Does anybody have a solution for this or a better idea, how to solve this?

Thanks 

Otto