Objective: generate mercator tiles 256x256 from a huge jpeg2000 image.
Tool used: gdal2tiles.py
GDAL version: 3.2.2
Command line: gdal2tiles.py -z 19 -r [any] image.jp2 tiles/
Source image: image.jp2 is in CRS Lambert93 (2154), coming from IGN ORTHO-HR open database (resolution 20 cm per pixel) https://geoservices.ign.fr/documentation/diffusion/telechargement-donnees-libres.html#ortho-irc50cm-et-hr
Problem: there are some cracks in all tiles generated, visible on road or building edges (as shown in illustration). The artefact doesn't depend on the resampling method used.
The samples are 256x256 pixels tiles, generated with gdal2tiles, with different -r options. 1_original.png is an extract (done with QGIS) from jp2 original image, for the same area than the tile.
The source CRS is well defined in source image metadata, so I don't use -s option on command line to specify it (I tried, but it doesn't change anything as expected).