I use the GMT to plot the Sentinel-2 optical image data. The region is over the Arctic, so I choose some map projection suitable for there.
grdimage could plot the NaN value as transparent. But in this projection (-JB), the transparent is not perfect.
ps=bigmap.ps J=B80/82/80/85/5i gmt grdimage sub_low_byte.tif+b0,1,2, -Rsub_low_byte.tif -J$J -K -P -Q>$ps gmt pscoast -J -R -Lx1c/0.5c+c114/22+w5k -N1 -Bxa30 -Bya -BWNes --FONT_TITLE=10p -I1 -O >> $ps gmt psconvert $ps -A -P -Tg
Map look as:
So, I guess there maybe some small problems for
grdimage. Specially, when use such map projections.