custom_nodes/ComfyUI_experiments/sampler_tonemap.py

import torch


class ModelSamplerTonemapNoiseTest:
    @classmethod
    def INPUT_TYPES(s):
        return {"required": { "model": ("MODEL",),
                              "multiplier": ("FLOAT", {"default": 1.0, "min": 0.0, "max": 100.0, "step": 0.01}),
                              }}
    RETURN_TYPES = ("MODEL",)
    FUNCTION = "patch"

    CATEGORY = "custom_node_experiments"

    def patch(self, model, multiplier):
        
        def sampler_tonemap_reinhard(args):
            cond = args["cond"]
            uncond = args["uncond"]
            cond_scale = args["cond_scale"]
            noise_pred = (cond - uncond)
            noise_pred_vector_magnitude = (torch.linalg.vector_norm(noise_pred, dim=(1)) + 0.0000000001)[:,None]
            noise_pred /= noise_pred_vector_magnitude

            mean = torch.mean(noise_pred_vector_magnitude, dim=(1,2,3), keepdim=True)
            std = torch.std(noise_pred_vector_magnitude, dim=(1,2,3), keepdim=True)

            top = (std * 3 + mean) * multiplier

            #reinhard
            noise_pred_vector_magnitude *= (1.0 / top)
            new_magnitude = noise_pred_vector_magnitude / (noise_pred_vector_magnitude + 1.0)
            new_magnitude *= top

            return uncond + noise_pred * new_magnitude * cond_scale

        m = model.clone()
        m.set_model_sampler_cfg_function(sampler_tonemap_reinhard)
        return (m, )


NODE_CLASS_MAPPINGS = {
    "ModelSamplerTonemapNoiseTest": ModelSamplerTonemapNoiseTest,
}