py bindings -- fix bilateral grid (make output be color)
py bindings -- fix bilateral grid (make output be color)


Former-commit-id: 199a214d321f68db08ff4ef40accd612fb581552
darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide