InvokeAI/ldm/invoke/generator/img2img.py
2022-12-07 19:25:21 -05:00

98 lines
3.5 KiB
Python

'''
ldm.invoke.generator.img2img descends from ldm.invoke.generator
'''
import torch
import numpy as np
import PIL
from torch import Tensor
from PIL import Image
from ldm.invoke.devices import choose_autocast
from ldm.invoke.generator.base import Generator
from ldm.models.diffusion.ddim import DDIMSampler
from ldm.models.diffusion.shared_invokeai_diffusion import InvokeAIDiffuserComponent
class Img2Img(Generator):
def __init__(self, model, precision):
super().__init__(model, precision)
self.init_latent = None # by get_noise()
def get_make_image(self,prompt,sampler,steps,cfg_scale,ddim_eta,
conditioning,init_image,strength,step_callback=None,threshold=0.0,perlin=0.0,**kwargs):
"""
Returns a function returning an image derived from the prompt and the initial image
Return value depends on the seed at the time you call it.
"""
self.perlin = perlin
sampler.make_schedule(
ddim_num_steps=steps, ddim_eta=ddim_eta, verbose=False
)
if isinstance(init_image, PIL.Image.Image):
init_image = self._image_to_tensor(init_image.convert('RGB'))
scope = choose_autocast(self.precision)
with scope(self.model.device.type):
self.init_latent = self.model.get_first_stage_encoding(
self.model.encode_first_stage(init_image)
) # move to latent space
t_enc = int(strength * steps)
uc, c, extra_conditioning_info = conditioning
def make_image(x_T):
# encode (scaled latent)
z_enc = sampler.stochastic_encode(
self.init_latent,
torch.tensor([t_enc]).to(self.model.device),
noise=x_T
)
if self.free_gpu_mem and self.model.model.device != self.model.device:
self.model.model.to(self.model.device)
# decode it
samples = sampler.decode(
z_enc,
c,
t_enc,
img_callback = step_callback,
unconditional_guidance_scale=cfg_scale,
unconditional_conditioning=uc,
init_latent = self.init_latent, # changes how noising is performed in ksampler
extra_conditioning_info = extra_conditioning_info,
all_timesteps_count = steps
)
if self.free_gpu_mem:
self.model.model.to("cpu")
return self.sample_to_image(samples)
return make_image
def get_noise(self,width,height):
device = self.model.device
init_latent = self.init_latent
assert init_latent is not None,'call to get_noise() when init_latent not set'
if device.type == 'mps':
x = torch.randn_like(init_latent, device='cpu').to(device)
else:
x = torch.randn_like(init_latent, device=device)
if self.perlin > 0.0:
shape = init_latent.shape
x = (1-self.perlin)*x + self.perlin*self.get_perlin_noise(shape[3], shape[2])
return x
def _image_to_tensor(self, image:Image, normalize:bool=True)->Tensor:
image = np.array(image).astype(np.float32) / 255.0
if len(image.shape) == 2: # 'L' image, as in a mask
image = image[None,None]
else: # 'RGB' image
image = image[None].transpose(0, 3, 1, 2)
image = torch.from_numpy(image)
if normalize:
image = 2.0 * image - 1.0
return image.to(self.model.device)