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olivierhagolle / Start_maja

To process a Sentinel-2 time series with MAJA cloud detection and atmospheric correction processor
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Weird tile differences #8

Closed Greforb closed 6 years ago

Greforb commented 6 years ago

I ran approximately 38 scenes through MAJA, but seem to get some quite weird results in some cases. In this image you see 4 tiles from the same scene processed by MAJA. Can anybody give me a clue on what's going wrong? Why are the values so much off in two of them compared to the others? Is it because there is too much water in them or how can this happen? sent2ex2

olivierhagolle commented 6 years ago

Hi Greforb, When you open the tiles, I guess your viewer makes an automatic stretching depending on the content of the image. As the two tiles on the west have quite a lot of No data values, their histogram is quite different from the others. you should use a constant stretching, for instance stretching each RGB channel between 0 and 0.25 in reflectance units (0 and 2500 in numerical counts). Olivier

Greforb commented 6 years ago

Thanks a lot. How embarrassing if this the reason! But thanks again for very quick and helpful reply. Checking right now!

Greforb commented 6 years ago

Amazing, this solved it. Sorry for de-coupling my brain...