How to merge multiple geotiffs by the maximum value using gdal_merge.py?

Question

I'm try to use the gdal_merge.py to generate a a big composite image considering the maximum value per pixel (to avoid the no data value).

But I didn't find this option for gdal_merge.py. My code is:

python gdal_merge -o mergedLayerOutput.tif -q -v --optfile filesToMerge.txt

The result:

Any suggestion about?

Answer 1

Because you are trying to ignore the NoData values in the input rasters, I suggest you either set the NoData for each raster before merging (in which case gdal_merge.py will ignore those pixels on merging) or use the -n option to supply such a value at the execution call time.