PNG::Heuristic
Constants
AVERAGE = ->(prev : Scanline | ::Nil, curr : Scanline) do
curr.filter = FilterMethod::Average
curr
end
NONE = ->(prev : Scanline | ::Nil, curr : Scanline) do
curr
end
PAETH = ->(prev : Scanline | ::Nil, curr : Scanline) do
curr.filter = FilterMethod::Paeth
curr
end
SUB = ->(prev : Scanline | ::Nil, curr : Scanline) do
curr.filter = FilterMethod::Sub
curr
end
UP = ->(prev : Scanline | ::Nil, curr : Scanline) do
curr.filter = FilterMethod::Up
curr
end