<div dir="auto">Another more common way to address the problem is to perform a log transform on the image see <a href="https://theailearner.com/2019/01/01/log-transformation/" rel="noreferrer noreferrer noreferrer" target="_blank">https://theailearner.com/2019/01/01/log-transformation/</a><div dir="auto"><br></div><div dir="auto">I am not aware of any ootb log transform libraries. That link above does show how to do it in OpenCV and numpy. I would probably use Pillow my self and here is a link talking about how to do that - not my link and I have never used it so it could be wrong or very slow etc </div><div dir="auto"><br></div><div dir="auto"><a href="https://pythontic.com/image-processing/pillow/logarithmic%20transformation" target="_blank" rel="noreferrer">https://pythontic.com/image-processing/pillow/logarithmic%20transformation</a><br></div><div dir="auto"><br></div><div dir="auto">I guess the same thing could be done in GDAL. </div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, 10 Oct 2022, 10:40 Stefan Gofferje, <<a href="mailto:lists@home.gofferje.net" rel="noreferrer noreferrer noreferrer" target="_blank">lists@home.gofferje.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi all,<br>
<br>
I'm still tinkering on my <br>
automatic-download-satellite-data-and-create-images-from-my-area scripts <br>
and I was wondering if anybody could help me out or point me to some math.<br>
<br>
I'm currently using percentiles in a little Python script to compress <br>
the contrast of my images. The result is pretty OK but it breaks if <br>
large areas of the image are very bright, like clouds or snow.<br>
<br>
The Sentinelhub EO Browser offers a function HighlightCompressVisualizer <br>
(see <br>
<a href="https://docs.sentinel-hub.com/api/latest/evalscript/functions/#highlightcompressvisualizer" rel="noreferrer noreferrer noreferrer noreferrer noreferrer" target="_blank">https://docs.sentinel-hub.com/api/latest/evalscript/functions/#highlightcompressvisualizer</a>) <br>
which does that "a little" better.<br>
<br>
Is there anything comparable in gdal, python or any related library?<br>
That level of math is a little bit above me. High school was long ago...<br>
<br>
T:Stefan<br>
<br>
-- <br>
(o_ Stefan Gofferje | SCLT, MCP, CCSA<br>
//\ Reg'd Linux User #247167 | VCP #2263<br>
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