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blepping 553127a766 Add more tensor operations
Fixes

Documentation improvements
2024-08-04 08:42:54 -06:00

115 lines
3.2 KiB
Python

import torch
import torch.nn.functional as F
from comfy.utils import bislerp
from .external import MODULES as EXT
# The following is modified to work with latent images of ~0 mean from https://github.com/Jamy-L/Pytorch-Contrast-Adaptive-Sharpening/tree/main.
def contrast_adaptive_sharpening(x, amount=0.8, *, epsilon=1e-06):
"""
Performs a contrast adaptive sharpening on the batch of images x.
The algorithm is directly implemented from FidelityFX's source code,
that can be found here
https://github.com/GPUOpen-Effects/FidelityFX-CAS/blob/master/ffx-cas/ffx_cas.h
Parameters
----------
x : Tensor
Image or stack of images, of shape [batch, channels, ny, nx].
Batch and channel dimensions can be ommited.
amount : int [0, 1]
Amount of sharpening to do, 0 being minimum and 1 maximum
Returns
-------
Tensor
Processed stack of images.
"""
def on_abs_stacked(tensor_list, f, *args, **kwargs):
return f(torch.abs(torch.stack(tensor_list)), *args, **kwargs)[0]
x_padded = F.pad(x, pad=(1, 1, 1, 1))
x_padded = torch.complex(x_padded, torch.zeros_like(x_padded))
# each side gets padded with 1 pixel
# padding = same by default
# Extracting the 3x3 neighborhood around each pixel
# a b c
# d e f
# g h i
a = x_padded[..., :-2, :-2]
b = x_padded[..., :-2, 1:-1]
c = x_padded[..., :-2, 2:]
d = x_padded[..., 1:-1, :-2]
e = x_padded[..., 1:-1, 1:-1]
f = x_padded[..., 1:-1, 2:]
g = x_padded[..., 2:, :-2]
h = x_padded[..., 2:, 1:-1]
i = x_padded[..., 2:, 2:]
# Computing contrast
cross = (b, d, e, f, h)
mn = on_abs_stacked(cross, torch.min, axis=0)
mx = on_abs_stacked(cross, torch.max, axis=0)
diag = (a, c, g, i)
mn2 = on_abs_stacked(diag, torch.min, axis=0)
mx2 = on_abs_stacked(diag, torch.max, axis=0)
mx = mx + mx2
mn = mn + mn2
# Computing local weight
inv_mx = torch.reciprocal(mx + epsilon) # 1/mx
amp = inv_mx * mn
# scaling
amp = torch.sqrt(amp)
w = -amp * (amount * (1 / 5 - 1 / 8) + 1 / 8)
# w scales from 0 when amp=0 to K for amp=1
# K scales from -1/5 when amount=1 to -1/8 for amount=0
# The local conv filter is
# 0 w 0
# w 1 w
# 0 w 0
div = torch.reciprocal(1 + 4 * w)
output = ((b + d + f + h) * w + e) * div
return output.real.clamp(x.min(), x.max())
if "bleh" in EXT:
scale_samples = EXT["bleh"].latent_utils.scale_samples
UPSCALE_METHODS = EXT["bleh"].latent_utils.UPSCALE_METHODS
else:
UPSCALE_METHODS = ("bicubic", "bislerp", "bilinear", "nearest-exact", "area")
def scale_samples(
samples,
width,
height,
mode="bicubic",
sigma=None, # noqa: ARG001
):
if mode == "bislerp":
return bislerp(samples, width, height)
return F.interpolate(samples, size=(height, width), mode=mode)
if "sonar" in EXT:
get_noise_sampler = EXT["sonar"].noise.get_noise_sampler
else:
def get_noise_sampler(noise_type, x, *_args: list, **_kwargs: dict):
if noise_type != "gaussian":
raise ValueError("Only gaussian noise supported")
return lambda _s, _sn: torch.randn_like(x)