[gdal-dev] The histogram results from a vrt datsource when the rasters are partially overlapped

[Andrea Peri]

Hi,
I have a VRT datasource, with more raster inside.
Each raster is partially overlapped to the two near rasters.

My dubt is how the histogram retrieved using the API GetDefaultHistogram,
is counting the overlapping.

Infact the overlapping portin is more NULL values, but also there is
portion f informations.

Is in a pixel overlapped there is a NULL from frame1 and a VALUE from frame2.
I could guess the Histogram ignore the NULL from frame1 and count only
the VALUE from frame2.

But when the frame1 and frame2 give the differents values: VALUE1 and
VALUE2. In this case what is the value counted in the histogram ?

It count the top level raster only, the first raster only, use a mean
of both or count both duplicating so the number of cell in the results
?

Thx.

-- 
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Andrea Peri
. . . . . . . . .
qwerty àèìòù
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