ImageMagick等比切割图片

E:\tiles> convert land_ocean_ice_8192.tif -crop 256x256  -resize 50%  tile.4.%d.
png

E:\tiles> convert land_ocean_ice_8192.tif -resize 50% -crop 256x256  tile.4.%d.p
ng

E:\tiles> convert land_ocean_ice_8192.tif -resize 25% -crop 256x256  tile.3.%d.p
ng

E:\tiles> convert land_ocean_ice_8192.tif -resize 12.5% -crop 256x256  tile.2.%d
.png

E:\tiles> convert land_ocean_ice_8192.tif -resize 6.25% -crop 256x256  tile.1.%d
.png

E:\tiles> convert land_ocean_ice_8192.tif -resize 3.125% -crop 256x256  tile.0.%
d.png


http://www.imagemagick.org/Usage/crop/#crop_page