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sdnext/modules/postprocess/pixelart.py
Vladimir Mandic e55d473374 lint
Signed-off-by: Vladimir Mandic <mandic00@live.com>
2025-08-23 13:10:36 -04:00

340 lines
14 KiB
Python

from typing import List
import math
import torch
import torchvision
import numpy as np
from PIL import Image
from diffusers.utils import CONFIG_NAME
from diffusers.image_processor import PipelineImageInput
from diffusers.configuration_utils import ConfigMixin, register_to_config
from transformers import ImageProcessingMixin
from modules import devices
@devices.inference_context()
def img_to_pixelart(image: PipelineImageInput, sharpen: float = 0, block_size: int = 8, return_type: str = "pil", device: torch.device = "cpu") -> PipelineImageInput:
block_size_sq = block_size * block_size
processor = JPEGEncoder(block_size=block_size, cbcr_downscale=1)
new_image = processor.encode(image, device=device)
y = new_image[:,0,:,:].unsqueeze(1)
cb = new_image[:,block_size_sq,:,:].unsqueeze(1)
cr = new_image[:,block_size_sq*2,:,:].unsqueeze(1)
if sharpen > 0:
ycbcr = torch.cat([y,cb,cr], dim=1)
laplacian_kernel = torch.tensor(
[
[[[ 0, 1, 0], [1, -4, 1], [ 0, 1, 0]]],
[[[ 0, 1, 0], [1, -4, 1], [ 0, 1, 0]]],
[[[ 0, 1, 0], [1, -4, 1], [ 0, 1, 0]]],
],
dtype=torch.float32,
).to(device)
ycbcr = ycbcr.sub_(torch.nn.functional.conv2d(ycbcr, laplacian_kernel, padding=1, groups=3), alpha=sharpen)
y = ycbcr[:,0,:,:].unsqueeze(1)
cb = ycbcr[:,1,:,:].unsqueeze(1)
cr = ycbcr[:,2,:,:].unsqueeze(1)
new_image = torch.zeros_like(new_image)
new_image[:,0,:,:] = y
new_image[:,block_size_sq,:,:] = cb
new_image[:,block_size_sq*2,:,:] = cr
new_image = processor.decode(new_image, return_type=return_type)
return new_image
@devices.inference_context()
def edge_detect_for_pixelart(image: PipelineImageInput, image_weight: float = 1.0, block_size: int = 8, device: torch.device = "cpu") -> torch.Tensor:
block_size_sq = block_size * block_size
new_image = process_image_input(image).to(device).to(dtype=torch.float32) / 255
new_image = new_image.permute(0,3,1,2)
batch_size, _channels, height, width = new_image.shape
block_height = height // block_size
block_width = width // block_size
min_pool = -torch.nn.functional.max_pool2d(-new_image, block_size, 1, block_size//2, 1, False, False)
min_pool = min_pool[:, :, :height, :width]
greyscale = (new_image[:,0,:,:] * 0.299).add_(new_image[:,1,:,:], alpha=0.587).add_(new_image[:,2,:,:], alpha=0.114)
greyscale = greyscale[:, :(new_image.shape[-2]//block_size)*block_size, :(new_image.shape[-1]//block_size)*block_size] # crop to a multiple of block_size
greyscale_reshaped = greyscale.reshape(batch_size, block_size, block_height, block_size, block_width)
greyscale_reshaped = greyscale_reshaped.permute(0,1,3,2,4)
greyscale_reshaped = greyscale_reshaped.reshape(batch_size, block_size_sq, block_height, block_width)
greyscale_range = greyscale_reshaped.amax(dim=1, keepdim=True).sub_(greyscale_reshaped.amin(dim=1, keepdim=True))
upsample = torchvision.transforms.Resize((height, width), interpolation=torchvision.transforms.InterpolationMode.BICUBIC)
range_weight = upsample(greyscale_range)
range_weight = range_weight.div_(range_weight.max())
weight_map = upsample((greyscale > greyscale.median()).to(dtype=torch.float32))
weight_map = weight_map.unsqueeze(0).add_(range_weight).mul_(image_weight / 2)
new_image = new_image.mul_(weight_map).addcmul_(min_pool, (1-weight_map))
new_image = new_image.permute(0,2,3,1).mul_(255).clamp_(0, 255)
return new_image
@devices.inference_context()
def rgb_to_ycbcr_tensor(image: torch.ByteTensor) -> torch.FloatTensor:
if image.dtype != torch.float32:
img = image.to(torch.float32).div_(255)
else:
img = image / 255
y = (img[:,:,:,0] * 0.299).add_(img[:,:,:,1], alpha=0.587).add_(img[:,:,:,2], alpha=0.114)
cb = (img[:,:,:,0] * -0.168935).add_(img[:,:,:,1], alpha=-0.331665).add_(img[:,:,:,2], alpha=0.50059).add_(0.5)
cr = (img[:,:,:,0] * 0.499813).add_(img[:,:,:,1], alpha=-0.418531).add_(img[:,:,:,2], alpha=-0.081282).add_(0.5)
ycbcr = torch.add(-1, torch.stack([y,cb,cr], dim=1), alpha=2)
return ycbcr
@devices.inference_context()
def ycbcr_tensor_to_rgb(ycbcr: torch.FloatTensor) -> torch.ByteTensor:
ycbcr_img = ycbcr / 2
y = ycbcr_img[:,0,:,:].add_(0.5)
cb = ycbcr_img[:,1,:,:]
cr = ycbcr_img[:,2,:,:]
r = (cr * 1.402525).add_(y)
g = (cb * -0.343730).add_(cr, alpha=-0.714401).add_(y)
b = (cb * 1.769905).add_(cr, alpha=0.000013).add_(y)
rgb = torch.stack([r,g,b], dim=-1).mul_(255).round_().clamp_(0,255).to(torch.uint8)
return rgb
@devices.inference_context()
def encode_single_channel_dct_2d(img: torch.FloatTensor, block_size: int=16, norm: str='ortho') -> torch.FloatTensor:
batch_size, height, width = img.shape
h_blocks = int(height//block_size)
w_blocks = int(width//block_size)
# batch_size, h_blocks, w_blocks, block_size_h, block_size_w
dct_tensor = img.view(batch_size, h_blocks, block_size, w_blocks, block_size).transpose(2,3).to(torch.float32)
dct_tensor = dct_2d(dct_tensor, norm=norm)
# batch_size, combined_block_size, h_blocks, w_blocks
dct_tensor = dct_tensor.reshape(batch_size, h_blocks, w_blocks, block_size*block_size).permute(0,3,1,2)
return dct_tensor
@devices.inference_context()
def decode_single_channel_dct_2d(img: torch.FloatTensor, norm: str='ortho') -> torch.FloatTensor:
batch_size, combined_block_size, h_blocks, w_blocks = img.shape
block_size = int(math.sqrt(combined_block_size))
height = int(h_blocks*block_size)
width = int(w_blocks*block_size)
img_tensor = img.permute(0,2,3,1).view(batch_size, h_blocks, w_blocks, block_size, block_size)
img_tensor = idct_2d(img_tensor, norm=norm)
img_tensor = img_tensor.permute(0,1,3,2,4).reshape(batch_size, height, width)
return img_tensor
@devices.inference_context()
def encode_jpeg_tensor(img: torch.FloatTensor, block_size: int=16, cbcr_downscale: int=2, norm: str='ortho') -> torch.FloatTensor:
img = img[:, :, :(img.shape[-2]//block_size)*block_size, :(img.shape[-1]//block_size)*block_size] # crop to a multiply of block_size
cbcr_block_size = block_size//cbcr_downscale
_, _, height, width = img.shape
downsample = torchvision.transforms.Resize((height//cbcr_downscale, width//cbcr_downscale), interpolation=torchvision.transforms.InterpolationMode.BICUBIC)
down_img = downsample(img[:, 1:,:,:])
y = encode_single_channel_dct_2d(img[:, 0, :,:], block_size=block_size, norm=norm)
cb = encode_single_channel_dct_2d(down_img[:, 0, :,:], block_size=cbcr_block_size, norm=norm)
cr = encode_single_channel_dct_2d(down_img[:, 1, :,:], block_size=cbcr_block_size, norm=norm)
return torch.cat([y,cb,cr], dim=1)
@devices.inference_context()
def decode_jpeg_tensor(jpeg_img: torch.FloatTensor, block_size: int=16, cbcr_downscale: int=2, norm: str='ortho') -> torch.FloatTensor:
_, _, h_blocks, w_blocks = jpeg_img.shape
y_block_size = block_size*block_size
cbcr_block_size = int((block_size//cbcr_downscale) ** 2)
cr_start = y_block_size + cbcr_block_size
y = jpeg_img[:, :y_block_size]
cb = jpeg_img[:, y_block_size:cr_start]
cr = jpeg_img[:, cr_start:]
y = decode_single_channel_dct_2d(y, norm=norm)
cb = decode_single_channel_dct_2d(cb, norm=norm)
cr = decode_single_channel_dct_2d(cr, norm=norm)
upsample = torchvision.transforms.Resize((h_blocks*block_size, w_blocks*block_size), interpolation=torchvision.transforms.InterpolationMode.BICUBIC)
cb = upsample(cb)
cr = upsample(cr)
return torch.stack([y,cb,cr], dim=1)
def process_image_input(images: PipelineImageInput) -> torch.ByteTensor:
if isinstance(images, list):
combined_images = []
for img in images:
if isinstance(img, Image.Image):
img = torch.from_numpy(np.asarray(img).copy()).unsqueeze(0)
combined_images.append(img)
elif isinstance(img, np.ndarray):
img = torch.from_numpy(img)
if img.ndim == 3:
img = img.unsqueeze(0)
combined_images.append(img)
elif isinstance(img, torch.Tensor):
if img.ndim == 3:
img = img.unsqueeze(0)
combined_images.append(img)
else:
raise RuntimeError(f"Invalid input! Given: {type(img)} should be in ('torch.Tensor', 'np.ndarray', 'PIL.Image.Image')")
combined_images = torch.cat(combined_images, dim=0)
elif isinstance(images, Image.Image):
combined_images = torch.from_numpy(np.asarray(images).copy()).unsqueeze(0)
elif isinstance(images, np.ndarray):
combined_images = torch.from_numpy(images)
if combined_images.ndim == 3:
combined_images = combined_images.unsqueeze(0)
elif isinstance(images, torch.Tensor):
combined_images = images
if combined_images.ndim == 3:
combined_images = combined_images.unsqueeze(0)
else:
raise RuntimeError(f"Invalid input! Given: {type(images)} should be in ('torch.Tensor', 'np.ndarray', 'PIL.Image.Image')")
return combined_images
class JPEGEncoder(ImageProcessingMixin, ConfigMixin):
config_name = CONFIG_NAME
@register_to_config
def __init__(
self,
block_size: int = 16,
cbcr_downscale: int = 2,
norm: str = "ortho",
latents_std: List[float] = None,
latents_mean: List[float] = None,
):
self.block_size = block_size
self.cbcr_downscale = cbcr_downscale
self.norm = norm
self.latents_std = latents_std
self.latents_mean = latents_mean
super().__init__()
@devices.inference_context()
def encode(self, images: PipelineImageInput, device: str="cpu") -> torch.FloatTensor:
"""
Encode RGB 0-255 image to JPEG Latents.
Args:
image (`PIL.Image.Image`, `np.ndarray` or `torch.Tensor`):
The image input, can be a PIL image, numpy array or pytorch tensor.
Must be an RGB image or a list of RGB images with 0-255 range and (batch_size, height, width, channels) shape.
Returns:
`torch.Tensor`:
The encoded JPEG Latents.
"""
combined_images = process_image_input(images).to(device)
latents = rgb_to_ycbcr_tensor(combined_images)
latents = encode_jpeg_tensor(latents, block_size=self.block_size, cbcr_downscale=self.cbcr_downscale, norm=self.norm)
if self.latents_mean is not None:
latents = latents - torch.tensor(self.latents_mean, device=device, dtype=torch.float32).view(1,-1,1,1)
if self.latents_std is not None:
latents = latents / torch.tensor(self.latents_std, device=device, dtype=torch.float32).view(1,-1,1,1)
return latents
@devices.inference_context()
def decode(self, latents: torch.FloatTensor, return_type: str="pil") -> PipelineImageInput:
latents = latents.to(dtype=torch.float32)
if self.latents_std is not None:
latents_std = torch.tensor(self.latents_std, device=latents.device, dtype=torch.float32).view(1,-1,1,1)
if self.latents_mean is not None:
latents_mean = torch.tensor(self.latents_mean, device=latents.device, dtype=torch.float32).view(1,-1,1,1)
latents = torch.addcmul(latents_mean, latents, latents_std)
else:
latents = latents * latents_std
elif self.latents_mean is not None:
latents = latents + torch.tensor(self.latents_mean, device=latents.device, dtype=torch.float32).view(1,-1,1,1)
images = decode_jpeg_tensor(latents, block_size=self.block_size, cbcr_downscale=self.cbcr_downscale, norm=self.norm)
images = ycbcr_tensor_to_rgb(images)
if return_type == "pt":
return images
elif return_type == "np":
return images.detach().cpu().numpy()
elif return_type == "pil":
image_list = []
for i in range(images.shape[0]):
image_list.append(Image.fromarray(images[i].detach().cpu().numpy()))
return image_list
else:
raise RuntimeError(f"Invalid return_type! Given: {return_type} should be in ('pt', 'np', 'pil')")
# dct functions are modified from https://github.com/zh217/torch-dct/blob/master/torch_dct/_dct.py (MIT license)
@devices.inference_context()
def dct(x, norm=None):
x_shape = x.shape
N = x_shape[-1]
x = x.contiguous().view(-1, N)
v = torch.cat([x[:, ::2], x[:, 1::2].flip([1])], dim=1)
Vc = torch.view_as_real(torch.fft.fft(v, dim=1))
k = - torch.arange(N, dtype=x.dtype, device=x.device)[None, :].mul_(math.pi / (2 * N))
W_r = torch.cos(k)
n_W_i = -torch.sin(k)
V = torch.addcmul((Vc[:, :, 0] * W_r), Vc[:, :, 1], n_W_i)
if norm == 'ortho':
V[:, 0].mul_(0.5 / math.sqrt(N))
V[:, 1:].mul_(0.5 / math.sqrt(N / 2))
V = V.view(x_shape).mul_(2)
return V
@devices.inference_context()
def idct(X, norm=None):
x_shape = X.shape
N = x_shape[-1]
X_v = X.contiguous().view(-1, N).div_(2)
if norm == 'ortho':
X_v[:, 0].mul_(math.sqrt(N) * 2)
X_v[:, 1:].mul_(math.sqrt(N / 2) * 2)
k = torch.arange(N, dtype=X.dtype, device=X.device)[None, :].mul_(math.pi / (2 * N))
W_r = torch.cos(k)
W_i = torch.sin(k)
V_t_i = torch.cat([X_v.new_zeros((X_v.shape[0], 1)), -(X_v.flip([1])[:, :-1])], dim=1)
V_r = torch.addcmul((X_v * W_r), V_t_i, -W_i)
V_i = torch.addcmul((X_v * W_i), V_t_i, W_r)
V = torch.cat([V_r.unsqueeze(2), V_i.unsqueeze(2)], dim=2)
v = torch.fft.irfft(torch.view_as_complex(V), n=V.shape[1], dim=1)
x = v.new_zeros(v.shape)
x[:, ::2] = v[:, :N - (N // 2)]
x[:, 1::2] = v.flip([1])[:, :N // 2]
x = x.view(x_shape)
return x
@devices.inference_context()
def dct_2d(x, norm=None):
X1 = dct(x, norm=norm).transpose_(-1, -2)
X2 = dct(X1, norm=norm).transpose_(-1, -2)
return X2
@devices.inference_context()
def idct_2d(X, norm=None):
x1 = idct(X, norm=norm).transpose_(-1, -2)
x2 = idct(x1, norm=norm).transpose_(-1, -2)
return x2