#odd

export j=-1; ls *.jpg | sort -n | while read x ; do let j+=2; fn=`printf %03d $j` ; echo mv \"$x\" p$fn.jpg; done | cat 

#even renumber backwards:
export j=0; ls SCN*.jpg | sort -rn | while read x ; do let j+=2; fn=`printf %03d $j` ; echo mv \"$x\" p$fn.jpg; done | cat

#crop
ls | awk '1==1 {printf("mogrify -crop 2100x1400+250+0 -rotate 90 +repage %s\n",$0);}'