Commit 160c377d authored by Patrick von Platen's avatar Patrick von Platen
Browse files

Make style

parent bb22d546
...@@ -32,8 +32,7 @@ def preprocess(image, w, h): ...@@ -32,8 +32,7 @@ def preprocess(image, w, h):
image = [image] image = [image]
if isinstance(image[0], PIL.Image.Image): if isinstance(image[0], PIL.Image.Image):
image = [np.array(i.resize((w, h), resample=PIL_INTERPOLATION['lanczos']))[ image = [np.array(i.resize((w, h), resample=PIL_INTERPOLATION["lanczos"]))[None, :] for i in image]
None, :] for i in image]
image = np.concatenate(image, axis=0) image = np.concatenate(image, axis=0)
image = np.array(image).astype(np.float32) / 255.0 image = np.array(image).astype(np.float32) / 255.0
image = image.transpose(0, 3, 1, 2) image = image.transpose(0, 3, 1, 2)
...@@ -45,7 +44,6 @@ def preprocess(image, w, h): ...@@ -45,7 +44,6 @@ def preprocess(image, w, h):
def slerp(t, v0, v1, DOT_THRESHOLD=0.9995): def slerp(t, v0, v1, DOT_THRESHOLD=0.9995):
if not isinstance(v0, np.ndarray): if not isinstance(v0, np.ndarray):
inputs_are_torch = True inputs_are_torch = True
input_device = v0.device input_device = v0.device
...@@ -82,7 +80,6 @@ def set_requires_grad(model, value): ...@@ -82,7 +80,6 @@ def set_requires_grad(model, value):
class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
def __init__( def __init__(
self, self,
vae: AutoencoderKL, vae: AutoencoderKL,
...@@ -112,15 +109,14 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -112,15 +109,14 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
self.feature_extractor_size = ( self.feature_extractor_size = (
feature_extractor.size feature_extractor.size
if isinstance(feature_extractor.size, int) if isinstance(feature_extractor.size, int)
else feature_extractor.size['shortest_edge'] else feature_extractor.size["shortest_edge"]
) )
self.normalize = transforms.Normalize( self.normalize = transforms.Normalize(mean=feature_extractor.image_mean, std=feature_extractor.image_std)
mean=feature_extractor.image_mean, std=feature_extractor.image_std)
set_requires_grad(self.text_encoder, False) set_requires_grad(self.text_encoder, False)
set_requires_grad(self.clip_model, False) set_requires_grad(self.clip_model, False)
def enable_attention_slicing(self, slice_size: Optional[Union[str, int]] = 'auto'): def enable_attention_slicing(self, slice_size: Optional[Union[str, int]] = "auto"):
if slice_size == 'auto': if slice_size == "auto":
# half the attention head size is usually a good trade-off between # half the attention head size is usually a good trade-off between
# speed and memory # speed and memory
slice_size = self.unet.config.attention_head_dim // 2 slice_size = self.unet.config.attention_head_dim // 2
...@@ -143,8 +139,7 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -143,8 +139,7 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
def get_timesteps(self, num_inference_steps, strength, device): def get_timesteps(self, num_inference_steps, strength, device):
# get the original timestep using init_timestep # get the original timestep using init_timestep
init_timestep = min( init_timestep = min(int(num_inference_steps * strength), num_inference_steps)
int(num_inference_steps * strength), num_inference_steps)
t_start = max(num_inference_steps - init_timestep, 0) t_start = max(num_inference_steps - init_timestep, 0)
timesteps = self.scheduler.timesteps[t_start:] timesteps = self.scheduler.timesteps[t_start:]
...@@ -153,15 +148,13 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -153,15 +148,13 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
def prepare_latents(self, image, timestep, batch_size, dtype, device, generator=None): def prepare_latents(self, image, timestep, batch_size, dtype, device, generator=None):
if not isinstance(image, torch.Tensor): if not isinstance(image, torch.Tensor):
raise ValueError( raise ValueError(f"`image` has to be of type `torch.Tensor` but is {type(image)}")
f'`image` has to be of type `torch.Tensor` but is {type(image)}'
)
image = image.to(device=device, dtype=dtype) image = image.to(device=device, dtype=dtype)
if isinstance(generator, list): if isinstance(generator, list):
init_latents = [ init_latents = [
self.vae.encode(image[i: i + 1]).latent_dist.sample(generator[i]) for i in range(batch_size) self.vae.encode(image[i : i + 1]).latent_dist.sample(generator[i]) for i in range(batch_size)
] ]
init_latents = torch.cat(init_latents, dim=0) init_latents = torch.cat(init_latents, dim=0)
else: else:
...@@ -171,8 +164,7 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -171,8 +164,7 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
init_latents = 0.18215 * init_latents init_latents = 0.18215 * init_latents
init_latents = init_latents.repeat_interleave(batch_size, dim=0) init_latents = init_latents.repeat_interleave(batch_size, dim=0)
noise = randn_tensor(init_latents.shape, noise = randn_tensor(init_latents.shape, generator=generator, device=device, dtype=dtype)
generator=generator, device=device, dtype=dtype)
# get latents # get latents
init_latents = self.scheduler.add_noise(init_latents, noise, timestep) init_latents = self.scheduler.add_noise(init_latents, noise, timestep)
...@@ -183,21 +175,16 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -183,21 +175,16 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
def get_image_description(self, image): def get_image_description(self, image):
transformed_image = self.coca_transform(image).unsqueeze(0) transformed_image = self.coca_transform(image).unsqueeze(0)
with torch.no_grad(), torch.cuda.amp.autocast(): with torch.no_grad(), torch.cuda.amp.autocast():
generated = self.coca_model.generate(transformed_image.to( generated = self.coca_model.generate(transformed_image.to(device=self.device, dtype=self.coca_model.dtype))
device=self.device, dtype=self.coca_model.dtype))
generated = self.coca_tokenizer.decode(generated[0].cpu().numpy()) generated = self.coca_tokenizer.decode(generated[0].cpu().numpy())
return generated.split('<end_of_text>')[0].replace('<start_of_text>', '').rstrip(' .,') return generated.split("<end_of_text>")[0].replace("<start_of_text>", "").rstrip(" .,")
def get_clip_image_embeddings(self, image, batch_size): def get_clip_image_embeddings(self, image, batch_size):
clip_image_input = self.feature_extractor.preprocess(image) clip_image_input = self.feature_extractor.preprocess(image)
clip_image_features = torch.from_numpy( clip_image_features = torch.from_numpy(clip_image_input["pixel_values"][0]).unsqueeze(0).to(self.device).half()
clip_image_input['pixel_values'][0]).unsqueeze(0).to(self.device).half() image_embeddings_clip = self.clip_model.get_image_features(clip_image_features)
image_embeddings_clip = self.clip_model.get_image_features( image_embeddings_clip = image_embeddings_clip / image_embeddings_clip.norm(p=2, dim=-1, keepdim=True)
clip_image_features) image_embeddings_clip = image_embeddings_clip.repeat_interleave(batch_size, dim=0)
image_embeddings_clip = image_embeddings_clip / \
image_embeddings_clip.norm(p=2, dim=-1, keepdim=True)
image_embeddings_clip = image_embeddings_clip.repeat_interleave(
batch_size, dim=0)
return image_embeddings_clip return image_embeddings_clip
@torch.enable_grad() @torch.enable_grad()
...@@ -213,20 +200,17 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -213,20 +200,17 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
): ):
latents = latents.detach().requires_grad_() latents = latents.detach().requires_grad_()
latent_model_input = self.scheduler.scale_model_input( latent_model_input = self.scheduler.scale_model_input(latents, timestep)
latents, timestep)
# predict the noise residual # predict the noise residual
noise_pred = self.unet(latent_model_input, timestep, noise_pred = self.unet(latent_model_input, timestep, encoder_hidden_states=text_embeddings).sample
encoder_hidden_states=text_embeddings).sample
if isinstance(self.scheduler, (PNDMScheduler, DDIMScheduler, DPMSolverMultistepScheduler)): if isinstance(self.scheduler, (PNDMScheduler, DDIMScheduler, DPMSolverMultistepScheduler)):
alpha_prod_t = self.scheduler.alphas_cumprod[timestep] alpha_prod_t = self.scheduler.alphas_cumprod[timestep]
beta_prod_t = 1 - alpha_prod_t beta_prod_t = 1 - alpha_prod_t
# compute predicted original sample from predicted noise also called # compute predicted original sample from predicted noise also called
# "predicted x_0" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf # "predicted x_0" of formula (12) from https://arxiv.org/pdf/2010.02502.pdf
pred_original_sample = ( pred_original_sample = (latents - beta_prod_t ** (0.5) * noise_pred) / alpha_prod_t ** (0.5)
latents - beta_prod_t ** (0.5) * noise_pred) / alpha_prod_t ** (0.5)
fac = torch.sqrt(beta_prod_t) fac = torch.sqrt(beta_prod_t)
sample = pred_original_sample * (fac) + latents * (1 - fac) sample = pred_original_sample * (fac) + latents * (1 - fac)
...@@ -234,8 +218,7 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -234,8 +218,7 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
sigma = self.scheduler.sigmas[index] sigma = self.scheduler.sigmas[index]
sample = latents - sigma * noise_pred sample = latents - sigma * noise_pred
else: else:
raise ValueError( raise ValueError(f"scheduler type {type(self.scheduler)} not supported")
f'scheduler type {type(self.scheduler)} not supported')
# Hardcode 0.18215 because stable-diffusion-2-base has not self.vae.config.scaling_factor # Hardcode 0.18215 because stable-diffusion-2-base has not self.vae.config.scaling_factor
sample = 1 / 0.18215 * sample sample = 1 / 0.18215 * sample
...@@ -246,11 +229,9 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -246,11 +229,9 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
image = self.normalize(image).to(latents.dtype) image = self.normalize(image).to(latents.dtype)
image_embeddings_clip = self.clip_model.get_image_features(image) image_embeddings_clip = self.clip_model.get_image_features(image)
image_embeddings_clip = image_embeddings_clip / \ image_embeddings_clip = image_embeddings_clip / image_embeddings_clip.norm(p=2, dim=-1, keepdim=True)
image_embeddings_clip.norm(p=2, dim=-1, keepdim=True)
loss = spherical_dist_loss( loss = spherical_dist_loss(image_embeddings_clip, original_image_embeddings_clip).mean() * clip_guidance_scale
image_embeddings_clip, original_image_embeddings_clip).mean() * clip_guidance_scale
grads = -torch.autograd.grad(loss, latents)[0] grads = -torch.autograd.grad(loss, latents)[0]
...@@ -277,121 +258,101 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -277,121 +258,101 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
eta: float = 0.0, eta: float = 0.0,
clip_guidance_scale: Optional[float] = 100, clip_guidance_scale: Optional[float] = 100,
generator: Optional[torch.Generator] = None, generator: Optional[torch.Generator] = None,
output_type: Optional[str] = 'pil', output_type: Optional[str] = "pil",
return_dict: bool = True, return_dict: bool = True,
slerp_latent_style_strength: float = 0.8, slerp_latent_style_strength: float = 0.8,
slerp_prompt_style_strength: float = 0.1, slerp_prompt_style_strength: float = 0.1,
slerp_clip_image_style_strength: float = 0.1, slerp_clip_image_style_strength: float = 0.1,
): ):
if isinstance(generator, list) and len(generator) != batch_size: if isinstance(generator, list) and len(generator) != batch_size:
raise ValueError( raise ValueError(f"You have passed {batch_size} batch_size, but only {len(generator)} generators.")
f'You have passed {batch_size} batch_size, but only {len(generator)} generators.')
if height % 8 != 0 or width % 8 != 0: if height % 8 != 0 or width % 8 != 0:
raise ValueError( raise ValueError(f"`height` and `width` have to be divisible by 8 but are {height} and {width}.")
f'`height` and `width` have to be divisible by 8 but are {height} and {width}.')
if isinstance(generator, torch.Generator) and batch_size > 1: if isinstance(generator, torch.Generator) and batch_size > 1:
generator = [generator] + [None] * (batch_size - 1) generator = [generator] + [None] * (batch_size - 1)
coca_is_none = [ coca_is_none = [
('model', self.coca_model is None), ("model", self.coca_model is None),
('tokenizer', self.coca_tokenizer is None), ("tokenizer", self.coca_tokenizer is None),
('transform', self.coca_transform is None) ("transform", self.coca_transform is None),
] ]
coca_is_none = [x[0] for x in coca_is_none if x[1]] coca_is_none = [x[0] for x in coca_is_none if x[1]]
coca_is_none_str = ', '.join(coca_is_none) coca_is_none_str = ", ".join(coca_is_none)
# generate prompts with coca model if prompt is None # generate prompts with coca model if prompt is None
if content_prompt is None: if content_prompt is None:
if len(coca_is_none): if len(coca_is_none):
raise ValueError( raise ValueError(
f'Content prompt is None and CoCa [{coca_is_none_str}] is None.' f"Content prompt is None and CoCa [{coca_is_none_str}] is None."
f'Set prompt or pass Coca [{coca_is_none_str}] to DiffusionPipeline.' f"Set prompt or pass Coca [{coca_is_none_str}] to DiffusionPipeline."
) )
content_prompt = self.get_image_description(content_image) content_prompt = self.get_image_description(content_image)
if style_prompt is None: if style_prompt is None:
if len(coca_is_none): if len(coca_is_none):
raise ValueError( raise ValueError(
f'Style prompt is None and CoCa [{coca_is_none_str}] is None.' f"Style prompt is None and CoCa [{coca_is_none_str}] is None."
f' Set prompt or pass Coca [{coca_is_none_str}] to DiffusionPipeline.' f" Set prompt or pass Coca [{coca_is_none_str}] to DiffusionPipeline."
) )
style_prompt = self.get_image_description(style_image) style_prompt = self.get_image_description(style_image)
# get prompt text embeddings for content and style # get prompt text embeddings for content and style
content_text_input = self.tokenizer( content_text_input = self.tokenizer(
content_prompt, content_prompt,
padding='max_length', padding="max_length",
max_length=self.tokenizer.model_max_length, max_length=self.tokenizer.model_max_length,
truncation=True, truncation=True,
return_tensors='pt', return_tensors="pt",
) )
content_text_embeddings = self.text_encoder( content_text_embeddings = self.text_encoder(content_text_input.input_ids.to(self.device))[0]
content_text_input.input_ids.to(self.device))[0]
style_text_input = self.tokenizer( style_text_input = self.tokenizer(
style_prompt, style_prompt,
padding='max_length', padding="max_length",
max_length=self.tokenizer.model_max_length, max_length=self.tokenizer.model_max_length,
truncation=True, truncation=True,
return_tensors='pt', return_tensors="pt",
) )
style_text_embeddings = self.text_encoder( style_text_embeddings = self.text_encoder(style_text_input.input_ids.to(self.device))[0]
style_text_input.input_ids.to(self.device))[0]
text_embeddings = slerp( text_embeddings = slerp(slerp_prompt_style_strength, content_text_embeddings, style_text_embeddings)
slerp_prompt_style_strength, content_text_embeddings, style_text_embeddings)
# duplicate text embeddings for each generation per prompt # duplicate text embeddings for each generation per prompt
text_embeddings = text_embeddings.repeat_interleave(batch_size, dim=0) text_embeddings = text_embeddings.repeat_interleave(batch_size, dim=0)
# set timesteps # set timesteps
accepts_offset = 'offset' in set(inspect.signature( accepts_offset = "offset" in set(inspect.signature(self.scheduler.set_timesteps).parameters.keys())
self.scheduler.set_timesteps).parameters.keys())
extra_set_kwargs = {} extra_set_kwargs = {}
if accepts_offset: if accepts_offset:
extra_set_kwargs['offset'] = 1 extra_set_kwargs["offset"] = 1
self.scheduler.set_timesteps(num_inference_steps, **extra_set_kwargs) self.scheduler.set_timesteps(num_inference_steps, **extra_set_kwargs)
# Some schedulers like PNDM have timesteps as arrays # Some schedulers like PNDM have timesteps as arrays
# It's more optimized to move all timesteps to correct device beforehand # It's more optimized to move all timesteps to correct device beforehand
self.scheduler.timesteps.to(self.device) self.scheduler.timesteps.to(self.device)
timesteps, num_inference_steps = self.get_timesteps( timesteps, num_inference_steps = self.get_timesteps(num_inference_steps, noise_strength, self.device)
num_inference_steps, noise_strength, self.device)
latent_timestep = timesteps[:1].repeat(batch_size) latent_timestep = timesteps[:1].repeat(batch_size)
# Preprocess image # Preprocess image
preprocessed_content_image = preprocess(content_image, width, height) preprocessed_content_image = preprocess(content_image, width, height)
content_latents = self.prepare_latents( content_latents = self.prepare_latents(
preprocessed_content_image, preprocessed_content_image, latent_timestep, batch_size, text_embeddings.dtype, self.device, generator
latent_timestep,
batch_size,
text_embeddings.dtype,
self.device,
generator
) )
preprocessed_style_image = preprocess(style_image, width, height) preprocessed_style_image = preprocess(style_image, width, height)
style_latents = self.prepare_latents( style_latents = self.prepare_latents(
preprocessed_style_image, preprocessed_style_image, latent_timestep, batch_size, text_embeddings.dtype, self.device, generator
latent_timestep,
batch_size,
text_embeddings.dtype,
self.device,
generator
) )
latents = slerp(slerp_latent_style_strength, latents = slerp(slerp_latent_style_strength, content_latents, style_latents)
content_latents, style_latents)
if clip_guidance_scale > 0: if clip_guidance_scale > 0:
content_clip_image_embedding = self.get_clip_image_embeddings( content_clip_image_embedding = self.get_clip_image_embeddings(content_image, batch_size)
content_image, batch_size) style_clip_image_embedding = self.get_clip_image_embeddings(style_image, batch_size)
style_clip_image_embedding = self.get_clip_image_embeddings(
style_image, batch_size)
clip_image_embeddings = slerp( clip_image_embeddings = slerp(
slerp_clip_image_style_strength, content_clip_image_embedding, style_clip_image_embedding) slerp_clip_image_style_strength, content_clip_image_embedding, style_clip_image_embedding
)
# here `guidance_scale` is defined analog to the guidance weight `w` of equation (2) # here `guidance_scale` is defined analog to the guidance weight `w` of equation (2)
# of the Imagen paper: https://arxiv.org/pdf/2205.11487.pdf . `guidance_scale = 1` # of the Imagen paper: https://arxiv.org/pdf/2205.11487.pdf . `guidance_scale = 1`
...@@ -400,13 +361,10 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -400,13 +361,10 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
# get unconditional embeddings for classifier free guidance # get unconditional embeddings for classifier free guidance
if do_classifier_free_guidance: if do_classifier_free_guidance:
max_length = content_text_input.input_ids.shape[-1] max_length = content_text_input.input_ids.shape[-1]
uncond_input = self.tokenizer( uncond_input = self.tokenizer([""], padding="max_length", max_length=max_length, return_tensors="pt")
[''], padding='max_length', max_length=max_length, return_tensors='pt') uncond_embeddings = self.text_encoder(uncond_input.input_ids.to(self.device))[0]
uncond_embeddings = self.text_encoder(
uncond_input.input_ids.to(self.device))[0]
# duplicate unconditional embeddings for each generation per prompt # duplicate unconditional embeddings for each generation per prompt
uncond_embeddings = uncond_embeddings.repeat_interleave( uncond_embeddings = uncond_embeddings.repeat_interleave(batch_size, dim=0)
batch_size, dim=0)
# For classifier free guidance, we need to do two forward passes. # For classifier free guidance, we need to do two forward passes.
# Here we concatenate the unconditional and text embeddings into a single batch # Here we concatenate the unconditional and text embeddings into a single batch
...@@ -418,25 +376,19 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -418,25 +376,19 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
# Unlike in other pipelines, latents need to be generated in the target device # Unlike in other pipelines, latents need to be generated in the target device
# for 1-to-1 results reproducibility with the CompVis implementation. # for 1-to-1 results reproducibility with the CompVis implementation.
# However this currently doesn't work in `mps`. # However this currently doesn't work in `mps`.
latents_shape = ( latents_shape = (batch_size, self.unet.config.in_channels, height // 8, width // 8)
batch_size, self.unet.config.in_channels, height // 8, width // 8)
latents_dtype = text_embeddings.dtype latents_dtype = text_embeddings.dtype
if latents is None: if latents is None:
if self.device.type == 'mps': if self.device.type == "mps":
# randn does not work reproducibly on mps # randn does not work reproducibly on mps
latents = torch.randn( latents = torch.randn(latents_shape, generator=generator, device="cpu", dtype=latents_dtype).to(
latents_shape, self.device
generator=generator, )
device='cpu',
dtype=latents_dtype
).to(self.device)
else: else:
latents = torch.randn( latents = torch.randn(latents_shape, generator=generator, device=self.device, dtype=latents_dtype)
latents_shape, generator=generator, device=self.device, dtype=latents_dtype)
else: else:
if latents.shape != latents_shape: if latents.shape != latents_shape:
raise ValueError( raise ValueError(f"Unexpected latents shape, got {latents.shape}, expected {latents_shape}")
f'Unexpected latents shape, got {latents.shape}, expected {latents_shape}')
latents = latents.to(self.device) latents = latents.to(self.device)
# scale the initial noise by the standard deviation required by the scheduler # scale the initial noise by the standard deviation required by the scheduler
...@@ -446,41 +398,34 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -446,41 +398,34 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
# eta (η) is only used with the DDIMScheduler, it will be ignored for other schedulers. # eta (η) is only used with the DDIMScheduler, it will be ignored for other schedulers.
# eta corresponds to η in DDIM paper: https://arxiv.org/abs/2010.02502 # eta corresponds to η in DDIM paper: https://arxiv.org/abs/2010.02502
# and should be between [0, 1] # and should be between [0, 1]
accepts_eta = 'eta' in set(inspect.signature( accepts_eta = "eta" in set(inspect.signature(self.scheduler.step).parameters.keys())
self.scheduler.step).parameters.keys())
extra_step_kwargs = {} extra_step_kwargs = {}
if accepts_eta: if accepts_eta:
extra_step_kwargs['eta'] = eta extra_step_kwargs["eta"] = eta
# check if the scheduler accepts generator # check if the scheduler accepts generator
accepts_generator = 'generator' in set( accepts_generator = "generator" in set(inspect.signature(self.scheduler.step).parameters.keys())
inspect.signature(self.scheduler.step).parameters.keys())
if accepts_generator: if accepts_generator:
extra_step_kwargs['generator'] = generator extra_step_kwargs["generator"] = generator
with self.progress_bar(total=num_inference_steps): with self.progress_bar(total=num_inference_steps):
for i, t in enumerate(timesteps): for i, t in enumerate(timesteps):
# expand the latents if we are doing classifier free guidance # expand the latents if we are doing classifier free guidance
latent_model_input = torch.cat( latent_model_input = torch.cat([latents] * 2) if do_classifier_free_guidance else latents
[latents] * 2) if do_classifier_free_guidance else latents latent_model_input = self.scheduler.scale_model_input(latent_model_input, t)
latent_model_input = self.scheduler.scale_model_input(
latent_model_input, t)
# predict the noise residual # predict the noise residual
noise_pred = self.unet( noise_pred = self.unet(latent_model_input, t, encoder_hidden_states=text_embeddings).sample
latent_model_input, t, encoder_hidden_states=text_embeddings).sample
# perform classifier free guidance # perform classifier free guidance
if do_classifier_free_guidance: if do_classifier_free_guidance:
noise_pred_uncond, noise_pred_text = noise_pred.chunk(2) noise_pred_uncond, noise_pred_text = noise_pred.chunk(2)
noise_pred = noise_pred_uncond + guidance_scale * \ noise_pred = noise_pred_uncond + guidance_scale * (noise_pred_text - noise_pred_uncond)
(noise_pred_text - noise_pred_uncond)
# perform clip guidance # perform clip guidance
if clip_guidance_scale > 0: if clip_guidance_scale > 0:
text_embeddings_for_guidance = ( text_embeddings_for_guidance = (
text_embeddings.chunk( text_embeddings.chunk(2)[1] if do_classifier_free_guidance else text_embeddings
2)[1] if do_classifier_free_guidance else text_embeddings
) )
noise_pred, latents = self.cond_fn( noise_pred, latents = self.cond_fn(
latents, latents,
...@@ -493,8 +438,7 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -493,8 +438,7 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
) )
# compute the previous noisy sample x_t -> x_t-1 # compute the previous noisy sample x_t -> x_t-1
latents = self.scheduler.step( latents = self.scheduler.step(noise_pred, t, latents, **extra_step_kwargs).prev_sample
noise_pred, t, latents, **extra_step_kwargs).prev_sample
# Hardcode 0.18215 because stable-diffusion-2-base has not self.vae.config.scaling_factor # Hardcode 0.18215 because stable-diffusion-2-base has not self.vae.config.scaling_factor
latents = 1 / 0.18215 * latents latents = 1 / 0.18215 * latents
...@@ -503,7 +447,7 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline): ...@@ -503,7 +447,7 @@ class CLIPGuidedImagesMixingStableDiffusion(DiffusionPipeline):
image = (image / 2 + 0.5).clamp(0, 1) image = (image / 2 + 0.5).clamp(0, 1)
image = image.cpu().permute(0, 2, 3, 1).numpy() image = image.cpu().permute(0, 2, 3, 1).numpy()
if output_type == 'pil': if output_type == "pil":
image = self.numpy_to_pil(image) image = self.numpy_to_pil(image)
if not return_dict: if not return_dict:
......
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