diff --git a/film_grain.py b/film_grain.py new file mode 100644 index 0000000..d9bad97 --- /dev/null +++ b/film_grain.py @@ -0,0 +1,151 @@ +import numpy as np +import torch + +class FilmGrain: + def __init__(self): + pass + + @classmethod + def INPUT_TYPES(s): + return { + "required": { + "image": ("IMAGE",), + "intensity": ("FLOAT", { + "default": 0.2, + "min": 0.0, + "max": 1.0, + "step": 0.01 + }), + "scale": ("FLOAT", { + "default": 10, + "min": 1, + "max": 100, + "step": 1 + }), + "temperature": ("FLOAT", { + "default": 0.0, + "min": -100, + "max": 100, + "step": 1 + }), + "vignette": ("FLOAT", { + "default": 0.0, + "min": 0.0, + "max": 10.0, + "step": 1.0 + }), + }, + } + + RETURN_TYPES = ("IMAGE",) + FUNCTION = "film_grain" + + CATEGORY = "postprocessing" + + def film_grain(self, image: torch.Tensor, intensity: float, scale: float, temperature: float, vignette: float): + batch_size, height, width, _ = image.shape + result = torch.zeros_like(image) + + for b in range(batch_size): + tensor_image = image[b].numpy() + + # Generate Perlin noise with shape (height, width) and scale + noise = self.generate_perlin_noise((height, width), scale) + noise = (noise - np.min(noise)) / (np.max(noise) - np.min(noise)) + + # Apply grain intensity + noise = (noise * 2 - 1) * intensity + + # Blend the noise with the image + grain_image = np.clip(tensor_image + noise[:, :, np.newaxis], 0, 1) + + # Apply temperature + grain_image = self.apply_temperature(grain_image, temperature) + + # Apply vignette + grain_image = self.apply_vignette(grain_image, vignette) + + tensor = torch.from_numpy(grain_image).unsqueeze(0) + result[b] = tensor + + return (result,) + + def generate_perlin_noise(self, shape, scale, octaves=4, persistence=0.5, lacunarity=2): + def smoothstep(t): + return t * t * (3.0 - 2.0 * t) + + def lerp(t, a, b): + return a + t * (b - a) + + def gradient(h, x, y): + vectors = np.array([[1, 1], [-1, 1], [1, -1], [-1, -1]]) + g = vectors[h % 4] + return g[:, :, 0] * x + g[:, :, 1] * y + + height, width = shape + noise = np.zeros(shape) + + for octave in range(octaves): + octave_scale = scale * lacunarity ** octave + x = np.linspace(0, 1, width, endpoint=False) + y = np.linspace(0, 1, height, endpoint=False) + X, Y = np.meshgrid(x, y) + X, Y = X * octave_scale, Y * octave_scale + + xi = X.astype(int) + yi = Y.astype(int) + + xf = X - xi + yf = Y - yi + + u = smoothstep(xf) + v = smoothstep(yf) + + n00 = gradient(np.random.randint(0, 4, (height, width)), xf, yf) + n01 = gradient(np.random.randint(0, 4, (height, width)), xf, yf - 1) + n10 = gradient(np.random.randint(0, 4, (height, width)), xf - 1, yf) + n11 = gradient(np.random.randint(0, 4, (height, width)), xf - 1, yf - 1) + + x1 = lerp(u, n00, n10) + x2 = lerp(u, n01, n11) + y1 = lerp(v, x1, x2) + + noise += y1 * persistence ** octave + + return noise / (1 - persistence ** octaves) + + def apply_temperature(self, image, temperature): + if temperature == 0: + return image + + temperature /= 100 + + new_image = image.copy() + + if temperature > 0: + new_image[:, :, 0] *= 1 + temperature + new_image[:, :, 1] *= 1 + temperature * 0.4 + else: + new_image[:, :, 2] *= 1 - temperature + + return np.clip(new_image, 0, 1) + + def apply_vignette(self, image, vignette_strength): + if vignette_strength == 0: + return image + + height, width, _ = image.shape + x = np.linspace(-1, 1, width) + y = np.linspace(-1, 1, height) + X, Y = np.meshgrid(x, y) + radius = np.sqrt(X ** 2 + Y ** 2) + + # Map vignette strength from 0-10 to 1.800-0.800 + mapped_vignette_strength = 1.8 - (vignette_strength - 1) * 0.1 + vignette = 1 - np.clip(radius / mapped_vignette_strength, 0, 1) + + return np.clip(image * vignette[..., np.newaxis], 0, 1) + +NODE_CLASS_MAPPINGS = { + "FilmGrain": FilmGrain, +}