samples_2.4 => samples

share/grafx2/scripts/samples/picture/thomson/lib/bayer.lua

@@ -0,0 +1,68 @@
+-- bayer.lua : bayer matrix suppport.
+--
+-- Version: 02-jan-2017
+--
+-- Copyright 2016-2017 by Samuel Devulder
+--
+-- This program is free software; you can redistribute
+-- it and/or modify it under the terms of the GNU
+-- General Public License as published by the Free
+-- Software Foundation; version 2 of the License.
+-- See <http://www.gnu.org/licenses/>
+
+if not bayer then
+	bayer = {}
+
+	-- doubles a matrix rows and columns
+	function bayer.double(matrix)
+		local m,n=#matrix,#matrix[1]
+		local r = {}
+		for j=1,m*2 do
+			local t = {}
+			for i=1,n*2 do t[i]=0; end
+			r[j] = t;
+		end
+
+		-- 0 3
+		-- 2 1
+		for j=1,m do
+			for i=1,n do
+				local v = 4*matrix[j][i]
+				r[m*0+j][n*0+i] = v-3
+				r[m*1+j][n*1+i] = v-2
+				r[m*1+j][n*0+i] = v-1
+				r[m*0+j][n*1+i] = v-0
+			end
+		end
+
+		return r;
+	end
+
+	-- returns a version of the matrix normalized into
+	-- the 0-1 range
+	function bayer.norm(matrix)
+		local m,n=#matrix,#matrix[1]
+		local max,ret = 0,{}
+		for j=1,m do
+			for i=1,n do
+				max = math.max(max,matrix[j][i])
+			end
+		end
+		-- max=max+1
+		for j=1,m do
+			ret[j] = {}
+			for i=1,n do
+				ret[j][i]=matrix[j][i]/max
+			end
+		end
+		return ret
+	end
+
+	-- returns a normalized order-n bayer matrix
+	function bayer.make(n)
+		local m = {{1}}
+		while n>1 do n,m = n/2,bayer.double(m) end
+		return bayer.norm(m)
+	end
+
+end -- Bayer