converting an image to tilemap does not remove duplicate tiles

[seedy1812]

gfx2next.exe -tile-size=8x8 -colors-4bit -pal-rgb332 bg.png

Tile Size = 8 x 8
Processing 'bg.png'...
Warning tile count > 256!
Map Size = 40 x 10
Tile Offset = 0
Tile Palette = 0
Tile Count = 400

[benbaker76]

Take a look at these options:

-tile-norepeat 	Remove repeating tiles
-tile-nomirror 	Remove repeating and mirrored tiles
-tile-norotate 	Remove repeating, rotating and mirrored tiles