gdalwarp -te tilexmin tileymin tilexmax tileymax
-t_srs targetproj.wkt
-of GTiff
bigmosaic.tiff smalltile.tif

#!/usr/bin/env python
import rsgislib
from rsgislib import imageutils
inputImage = './Rasters/injune_p142_casi_sub_utm.kea'
outBase = './TestOutputs/Tiles/injune_p142_casi_sub_utm'
width = 100
height = width
overlap = 5
offsettiling = 0
format = 'KEA'
dataType = rsgislib.TYPE_32INT
ext='kea'
imageutils.createTiles(inputImage, outBase, width, height, overlap, offsettiling, gdalformat, dataType, ext)