ComputeBandStats非常慢

Question

When I try to use ComputeBandStats it takes extremely long time to finish. Is there any way to speed up the process?

Here is my code:

inIMG = gdal.Open(infile)
bandas = [inIMG.GetRasterBand(b+1) for b in range(3)]
print('hej1')
meanSD = [b.ComputeBandStats(1) for b in bandas]
print('hej2')

It prints out "hej1" pretty fast, but it only writes "hej2" after several hours. Therefore it seems that ComputeBandStats is the problem.

I tried it with no parameter (has worked at an earlier date) and with 1, but it doesn't seem to make any difference.

(I am using python 2.7 and gdal 1.11.3)

Answer 1

I found out that ComputeStatistics is much faster than ComputeBandStats, so I'm using it instead. I don't know exactly what the difference is, but aside from the speed advantage, ComputeStatistics also ignores no-data values, which turned out to be a problem for ComputeBandStats. It also calculates min, max, mean and std, which I all needed anyways.

This is the change I made:

inIMG = gdal.Open(infile)
bandas = [inIMG.GetRasterBand(b+1) for b in range(3)]
print('hej1')
stats = [b.ComputeStatistics(False) for b in bandas]
print('hej2')