Subversion Repositories Kolibri OS

-- Apply a kind of AA filter on picture

-- Get the picture size

w, h = getpicturesize();

-- Here is the filtering matrix

 matrix = {

	 {  0, -1,  0 },

	 { -1,  5, -1 },

	 {  0, -1,  0 }};

-- Loop trough all the pixels

-- To make this script simpler we don't handle the picture borders

-- (the matrix would get pixels outside the picture space)

-- for var = start_value, end_value, step do ...

for y = 1, h - 2, 1 do

	for x = 1, w - 2, 1 do

		filtered =

			matrix[1][1] * getbackuppixel(x - 1, y - 1) +

			matrix[1][2] * getbackuppixel(x    , y - 1) +

			matrix[1][3] * getbackuppixel(x + 1, y - 1) +

			matrix[2][1] * getbackuppixel(x - 1, y    ) +

			matrix[2][2] * getbackuppixel(x    , y    ) +

			matrix[2][3] * getbackuppixel(x + 1, y    ) +

			matrix[3][1] * getbackuppixel(x - 1, y + 1) +

			matrix[3][2] * getbackuppixel(x    , y + 1) +

			matrix[3][3] * getbackuppixel(x + 1, y + 1);

		putpicturepixel(x,y,filtered);

	end

end