I ran gdal - nearblack on a Landsatlook image with geographic reference as follows:
nearblack -o c:\test\test_nearblack.TIF -of GTiff c:\test\LC08_L1TP_179044_20181228_20181228_01_RT.tif
The input file size is 4 Mb, output is a whopping 173 Mb. Is this expected behaviour? If so, why?
Note that the results is technically all correct, all boundary pixels are neatly set to 0,0,0. It's just that the large resulting large files are less convenient to work with.
I'm using GDAL 2.1.2.