Filtering Tiles

Hello, I have been trying to make a 128x128 filter a set of 16x16 tiles that are in a map arrar of 32x32, but only 16x14 of the array are shown at a time.



here is a picture of what im trying to do... :( if someone could give me a suggestion please post it or contact me thru email.

edit:
the filter is 128x128 but the tiles are 16x16 some 16x16 won't have the filtering, so I need to breakup the 128x128 image into 16x16 and thru them into the array but keep the 128x128 look

I hope that made sense

Here is some code

Function DrawMap()

	Local tx:Int, ty:Int
	
	For tx = mapx To 15 + mapx
		For ty = mapy To 13 + mapy
			DrawImage g_sheet,(tx-mapx)*32,(ty-mapy)*32,tilemap[tx,ty,0]
			SetBlend(shadeblend)
				DrawImage g_filter,(tx-mapx)*32,(ty-mapy)*32,filtermap[tx,ty,0] ' THIS IS THE FILTER!!!
			SetBlend(solidblend)
		Next
	Next

End Function

' THIS IS THE BREAKIN UP THE FILTER... VVVVVV ...
' THIS IS WHAT ISN'T WORKIN :(

Function DrawFilter()

	Local ox:Int, oy:Int
	Local curfilter:Int=0, currow:Int=1, curcol:Int=-1
		
	For ox = 0 To 31
		curcol = curcol + 1
		If curcol > 8 Then curcol = 0 ; currow = currow + 1
		For oy = 0 To 31
			filtermap[ox,oy,0] = curcol * currow
			currow = currow + 1
			If currow > 7 Then currow = 0
		Next
	Next

End Function