ComfyUI/comfy_extras/nodes_ideogram4.py
2026-06-03 08:41:44 -07:00

65 lines
2.2 KiB
Python

"""Ideogram 4 sampling helper
"""
import math
import torch
from typing_extensions import override
from comfy_api.latest import ComfyExtension, io
_LOGSNR_MIN = -15.0
_LOGSNR_MAX = 18.0
def _logit_normal_schedule(u, mean, std):
# Reference time (0=noise..1=clean) via the probit/ndtri quantile.
u = torch.as_tensor(u, dtype=torch.float64)
t = 1.0 - torch.special.expit(mean + std * torch.special.ndtri(u))
t_min = 1.0 / (1.0 + math.exp(0.5 * _LOGSNR_MAX))
t_max = 1.0 / (1.0 + math.exp(0.5 * _LOGSNR_MIN))
return t.clamp(t_min, t_max)
def ideogram4_sigmas(num_steps, width, height, mu, std):
"""Descending sigmas (len num_steps+1) for the reference schedule.
mu + the resolution term form the logSNR shift; std is the spread.
"""
mean = mu + 0.5 * math.log((width * height) / (512 * 512))
u = torch.linspace(0.0, 1.0, num_steps + 1, dtype=torch.float64)
sigmas = (1.0 - _logit_normal_schedule(u, mean, std)).flip(0)
sigmas[-1] = 0.0 # clamp leaves ~6e-4; force full denoise
return sigmas.to(torch.float32)
class Ideogram4Scheduler(io.ComfyNode):
@classmethod
def define_schema(cls) -> io.Schema:
return io.Schema(
node_id="Ideogram4Scheduler",
display_name="Ideogram 4 Scheduler",
category="sampling/custom_sampling/schedulers",
inputs=[
io.Int.Input("steps", default=20, min=1, max=200),
io.Int.Input("width", default=1024, min=256, max=8192, step=16),
io.Int.Input("height", default=1024, min=256, max=8192, step=16),
io.Float.Input("mu", default=0.0, min=-10.0, max=10.0, step=0.05),
io.Float.Input("std", default=1.75, min=0.1, max=5.0, step=0.05),
],
outputs=[io.Sigmas.Output()],
)
@classmethod
def execute(cls, steps, width, height, mu, std) -> io.NodeOutput:
return io.NodeOutput(ideogram4_sigmas(steps, width, height, mu, std))
class Ideogram4Extension(ComfyExtension):
@override
async def get_node_list(self) -> list[type[io.ComfyNode]]:
return [Ideogram4Scheduler]
async def comfy_entrypoint() -> Ideogram4Extension:
return Ideogram4Extension()