InvokeAI/ldm/models/diffusion/shared_invokeai_diffusion.py
Jonathan 093174942b
Add thresholding for all diffusers types (#2479)
`generator` now asks `InvokeAIDiffuserComponent` to do postprocessing work on latents after every step. Thresholding - now implemented as replacing latents outside of the threshold with random noise - is called at this point. This postprocessing step is also where we can hook up symmetry and other image latent manipulations in the future.

Note: code at this layer doesn't need to worry about MPS as relevant torch functions are wrapped and made MPS-safe by `generator.py`.
2023-02-14 18:00:34 -06:00

407 lines
21 KiB
Python

import math
from contextlib import contextmanager
from dataclasses import dataclass
from math import ceil
from typing import Callable, Optional, Union, Any, Dict
import numpy as np
import torch
from diffusers.models.cross_attention import AttnProcessor
from ldm.models.diffusion.cross_attention_control import Arguments, \
restore_default_cross_attention, override_cross_attention, Context, get_cross_attention_modules, \
CrossAttentionType, SwapCrossAttnContext
from ldm.models.diffusion.cross_attention_map_saving import AttentionMapSaver
@dataclass(frozen=True)
class PostprocessingSettings:
threshold: float
warmup: float
class InvokeAIDiffuserComponent:
'''
The aim of this component is to provide a single place for code that can be applied identically to
all InvokeAI diffusion procedures.
At the moment it includes the following features:
* Cross attention control ("prompt2prompt")
* Hybrid conditioning (used for inpainting)
'''
debug_thresholding = False
@dataclass
class ExtraConditioningInfo:
tokens_count_including_eos_bos: int
cross_attention_control_args: Optional[Arguments] = None
@property
def wants_cross_attention_control(self):
return self.cross_attention_control_args is not None
def __init__(self, model, model_forward_callback:
Callable[[torch.Tensor, torch.Tensor, torch.Tensor, Optional[dict[str,Any]]], torch.Tensor],
is_running_diffusers: bool=False,
):
"""
:param model: the unet model to pass through to cross attention control
:param model_forward_callback: a lambda with arguments (x, sigma, conditioning_to_apply). will be called repeatedly. most likely, this should simply call model.forward(x, sigma, conditioning)
"""
self.conditioning = None
self.model = model
self.is_running_diffusers = is_running_diffusers
self.model_forward_callback = model_forward_callback
self.cross_attention_control_context = None
@contextmanager
def custom_attention_context(self,
extra_conditioning_info: Optional[ExtraConditioningInfo],
step_count: int):
do_swap = extra_conditioning_info is not None and extra_conditioning_info.wants_cross_attention_control
old_attn_processor = None
if do_swap:
old_attn_processor = self.override_cross_attention(extra_conditioning_info,
step_count=step_count)
try:
yield None
finally:
if old_attn_processor is not None:
self.restore_default_cross_attention(old_attn_processor)
# TODO resuscitate attention map saving
#self.remove_attention_map_saving()
def override_cross_attention(self, conditioning: ExtraConditioningInfo, step_count: int) -> Dict[str, AttnProcessor]:
"""
setup cross attention .swap control. for diffusers this replaces the attention processor, so
the previous attention processor is returned so that the caller can restore it later.
"""
self.conditioning = conditioning
self.cross_attention_control_context = Context(
arguments=self.conditioning.cross_attention_control_args,
step_count=step_count
)
return override_cross_attention(self.model,
self.cross_attention_control_context,
is_running_diffusers=self.is_running_diffusers)
def restore_default_cross_attention(self, restore_attention_processor: Optional['AttnProcessor']=None):
self.conditioning = None
self.cross_attention_control_context = None
restore_default_cross_attention(self.model,
is_running_diffusers=self.is_running_diffusers,
restore_attention_processor=restore_attention_processor)
def setup_attention_map_saving(self, saver: AttentionMapSaver):
def callback(slice, dim, offset, slice_size, key):
if dim is not None:
# sliced tokens attention map saving is not implemented
return
saver.add_attention_maps(slice, key)
tokens_cross_attention_modules = get_cross_attention_modules(self.model, CrossAttentionType.TOKENS)
for identifier, module in tokens_cross_attention_modules:
key = ('down' if identifier.startswith('down') else
'up' if identifier.startswith('up') else
'mid')
module.set_attention_slice_calculated_callback(
lambda slice, dim, offset, slice_size, key=key: callback(slice, dim, offset, slice_size, key))
def remove_attention_map_saving(self):
tokens_cross_attention_modules = get_cross_attention_modules(self.model, CrossAttentionType.TOKENS)
for _, module in tokens_cross_attention_modules:
module.set_attention_slice_calculated_callback(None)
def do_diffusion_step(self, x: torch.Tensor, sigma: torch.Tensor,
unconditioning: Union[torch.Tensor,dict],
conditioning: Union[torch.Tensor,dict],
unconditional_guidance_scale: float,
step_index: Optional[int]=None,
total_step_count: Optional[int]=None,
):
"""
:param x: current latents
:param sigma: aka t, passed to the internal model to control how much denoising will occur
:param unconditioning: embeddings for unconditioned output. for hybrid conditioning this is a dict of tensors [B x 77 x 768], otherwise a single tensor [B x 77 x 768]
:param conditioning: embeddings for conditioned output. for hybrid conditioning this is a dict of tensors [B x 77 x 768], otherwise a single tensor [B x 77 x 768]
:param unconditional_guidance_scale: aka CFG scale, controls how much effect the conditioning tensor has
:param step_index: counts upwards from 0 to (step_count-1) (as passed to setup_cross_attention_control, if using). May be called multiple times for a single step, therefore do not assume that its value will monotically increase. If None, will be estimated by comparing sigma against self.model.sigmas .
:return: the new latents after applying the model to x using unscaled unconditioning and CFG-scaled conditioning.
"""
cross_attention_control_types_to_do = []
context: Context = self.cross_attention_control_context
if self.cross_attention_control_context is not None:
percent_through = self.calculate_percent_through(sigma, step_index, total_step_count)
cross_attention_control_types_to_do = context.get_active_cross_attention_control_types_for_step(percent_through)
wants_cross_attention_control = (len(cross_attention_control_types_to_do) > 0)
wants_hybrid_conditioning = isinstance(conditioning, dict)
if wants_hybrid_conditioning:
unconditioned_next_x, conditioned_next_x = self.apply_hybrid_conditioning(x, sigma, unconditioning, conditioning)
elif wants_cross_attention_control:
unconditioned_next_x, conditioned_next_x = self.apply_cross_attention_controlled_conditioning(x, sigma, unconditioning, conditioning, cross_attention_control_types_to_do)
else:
unconditioned_next_x, conditioned_next_x = self.apply_standard_conditioning(x, sigma, unconditioning, conditioning)
combined_next_x = self._combine(unconditioned_next_x, conditioned_next_x, unconditional_guidance_scale)
return combined_next_x
def do_latent_postprocessing(
self,
postprocessing_settings: PostprocessingSettings,
latents: torch.Tensor,
sigma,
step_index,
total_step_count
) -> torch.Tensor:
if postprocessing_settings is not None:
percent_through = self.calculate_percent_through(sigma, step_index, total_step_count)
latents = self.apply_threshold(postprocessing_settings, latents, percent_through)
return latents
def calculate_percent_through(self, sigma, step_index, total_step_count):
if step_index is not None and total_step_count is not None:
# 🧨diffusers codepath
percent_through = step_index / total_step_count # will never reach 1.0 - this is deliberate
else:
# legacy compvis codepath
# TODO remove when compvis codepath support is dropped
if step_index is None and sigma is None:
raise ValueError(
f"Either step_index or sigma is required when doing cross attention control, but both are None.")
percent_through = self.estimate_percent_through(step_index, sigma)
return percent_through
# methods below are called from do_diffusion_step and should be considered private to this class.
def apply_standard_conditioning(self, x, sigma, unconditioning, conditioning):
# fast batched path
x_twice = torch.cat([x] * 2)
sigma_twice = torch.cat([sigma] * 2)
both_conditionings = torch.cat([unconditioning, conditioning])
both_results = self.model_forward_callback(x_twice, sigma_twice, both_conditionings)
unconditioned_next_x, conditioned_next_x = both_results.chunk(2)
if conditioned_next_x.device.type == 'mps':
# prevent a result filled with zeros. seems to be a torch bug.
conditioned_next_x = conditioned_next_x.clone()
return unconditioned_next_x, conditioned_next_x
def apply_hybrid_conditioning(self, x, sigma, unconditioning, conditioning):
assert isinstance(conditioning, dict)
assert isinstance(unconditioning, dict)
x_twice = torch.cat([x] * 2)
sigma_twice = torch.cat([sigma] * 2)
both_conditionings = dict()
for k in conditioning:
if isinstance(conditioning[k], list):
both_conditionings[k] = [
torch.cat([unconditioning[k][i], conditioning[k][i]])
for i in range(len(conditioning[k]))
]
else:
both_conditionings[k] = torch.cat([unconditioning[k], conditioning[k]])
unconditioned_next_x, conditioned_next_x = self.model_forward_callback(x_twice, sigma_twice, both_conditionings).chunk(2)
return unconditioned_next_x, conditioned_next_x
def apply_cross_attention_controlled_conditioning(self,
x: torch.Tensor,
sigma,
unconditioning,
conditioning,
cross_attention_control_types_to_do):
if self.is_running_diffusers:
return self.apply_cross_attention_controlled_conditioning__diffusers(x, sigma, unconditioning, conditioning, cross_attention_control_types_to_do)
else:
return self.apply_cross_attention_controlled_conditioning__compvis(x, sigma, unconditioning, conditioning, cross_attention_control_types_to_do)
def apply_cross_attention_controlled_conditioning__diffusers(self,
x: torch.Tensor,
sigma,
unconditioning,
conditioning,
cross_attention_control_types_to_do):
context: Context = self.cross_attention_control_context
cross_attn_processor_context = SwapCrossAttnContext(modified_text_embeddings=context.arguments.edited_conditioning,
index_map=context.cross_attention_index_map,
mask=context.cross_attention_mask,
cross_attention_types_to_do=[])
# no cross attention for unconditioning (negative prompt)
unconditioned_next_x = self.model_forward_callback(x, sigma, unconditioning,
{"swap_cross_attn_context": cross_attn_processor_context})
# do requested cross attention types for conditioning (positive prompt)
cross_attn_processor_context.cross_attention_types_to_do = cross_attention_control_types_to_do
conditioned_next_x = self.model_forward_callback(x, sigma, conditioning,
{"swap_cross_attn_context": cross_attn_processor_context})
return unconditioned_next_x, conditioned_next_x
def apply_cross_attention_controlled_conditioning__compvis(self, x:torch.Tensor, sigma, unconditioning, conditioning, cross_attention_control_types_to_do):
# print('pct', percent_through, ': doing cross attention control on', cross_attention_control_types_to_do)
# slower non-batched path (20% slower on mac MPS)
# We are only interested in using attention maps for conditioned_next_x, but batching them with generation of
# unconditioned_next_x causes attention maps to *also* be saved for the unconditioned_next_x.
# This messes app their application later, due to mismatched shape of dim 0 (seems to be 16 for batched vs. 8)
# (For the batched invocation the `wrangler` function gets attention tensor with shape[0]=16,
# representing batched uncond + cond, but then when it comes to applying the saved attention, the
# wrangler gets an attention tensor which only has shape[0]=8, representing just self.edited_conditionings.)
# todo: give CrossAttentionControl's `wrangler` function more info so it can work with a batched call as well.
context:Context = self.cross_attention_control_context
try:
unconditioned_next_x = self.model_forward_callback(x, sigma, unconditioning)
# process x using the original prompt, saving the attention maps
#print("saving attention maps for", cross_attention_control_types_to_do)
for ca_type in cross_attention_control_types_to_do:
context.request_save_attention_maps(ca_type)
_ = self.model_forward_callback(x, sigma, conditioning)
context.clear_requests(cleanup=False)
# process x again, using the saved attention maps to control where self.edited_conditioning will be applied
#print("applying saved attention maps for", cross_attention_control_types_to_do)
for ca_type in cross_attention_control_types_to_do:
context.request_apply_saved_attention_maps(ca_type)
edited_conditioning = self.conditioning.cross_attention_control_args.edited_conditioning
conditioned_next_x = self.model_forward_callback(x, sigma, edited_conditioning)
context.clear_requests(cleanup=True)
except:
context.clear_requests(cleanup=True)
raise
return unconditioned_next_x, conditioned_next_x
def _combine(self, unconditioned_next_x, conditioned_next_x, guidance_scale):
# to scale how much effect conditioning has, calculate the changes it does and then scale that
scaled_delta = (conditioned_next_x - unconditioned_next_x) * guidance_scale
combined_next_x = unconditioned_next_x + scaled_delta
return combined_next_x
def apply_threshold(
self,
postprocessing_settings: PostprocessingSettings,
latents: torch.Tensor,
percent_through
) -> torch.Tensor:
threshold = postprocessing_settings.threshold
warmup = postprocessing_settings.warmup
if percent_through < warmup:
current_threshold = threshold + threshold * 5 * (1 - (percent_through / warmup))
else:
current_threshold = threshold
if current_threshold <= 0:
return latents
maxval = latents.max().item()
minval = latents.min().item()
scale = 0.7 # default value from #395
if self.debug_thresholding:
std, mean = [i.item() for i in torch.std_mean(latents)]
outside = torch.count_nonzero((latents < -current_threshold) | (latents > current_threshold))
print(f"\nThreshold: %={percent_through} threshold={current_threshold:.3f} (of {threshold:.3f})\n"
f" | min, mean, max = {minval:.3f}, {mean:.3f}, {maxval:.3f}\tstd={std}\n"
f" | {outside / latents.numel() * 100:.2f}% values outside threshold")
if maxval < current_threshold and minval > -current_threshold:
return latents
num_altered = 0
# MPS torch.rand_like is fine because torch.rand_like is wrapped in generate.py!
if maxval > current_threshold:
latents = torch.clone(latents)
maxval = np.clip(maxval * scale, 1, current_threshold)
num_altered += torch.count_nonzero(latents > maxval)
latents[latents > maxval] = torch.rand_like(latents[latents > maxval]) * maxval
if minval < -current_threshold:
latents = torch.clone(latents)
minval = np.clip(minval * scale, -current_threshold, -1)
num_altered += torch.count_nonzero(latents < minval)
latents[latents < minval] = torch.rand_like(latents[latents < minval]) * minval
if self.debug_thresholding:
print(f" | min, , max = {minval:.3f}, , {maxval:.3f}\t(scaled by {scale})\n"
f" | {num_altered / latents.numel() * 100:.2f}% values altered")
return latents
def estimate_percent_through(self, step_index, sigma):
if step_index is not None and self.cross_attention_control_context is not None:
# percent_through will never reach 1.0 (but this is intended)
return float(step_index) / float(self.cross_attention_control_context.step_count)
# find the best possible index of the current sigma in the sigma sequence
smaller_sigmas = torch.nonzero(self.model.sigmas <= sigma)
sigma_index = smaller_sigmas[-1].item() if smaller_sigmas.shape[0] > 0 else 0
# flip because sigmas[0] is for the fully denoised image
# percent_through must be <1
return 1.0 - float(sigma_index + 1) / float(self.model.sigmas.shape[0])
# print('estimated percent_through', percent_through, 'from sigma', sigma.item())
# todo: make this work
@classmethod
def apply_conjunction(cls, x, t, forward_func, uc, c_or_weighted_c_list, global_guidance_scale):
x_in = torch.cat([x] * 2)
t_in = torch.cat([t] * 2) # aka sigmas
deltas = None
uncond_latents = None
weighted_cond_list = c_or_weighted_c_list if type(c_or_weighted_c_list) is list else [(c_or_weighted_c_list, 1)]
# below is fugly omg
num_actual_conditionings = len(c_or_weighted_c_list)
conditionings = [uc] + [c for c,weight in weighted_cond_list]
weights = [1] + [weight for c,weight in weighted_cond_list]
chunk_count = ceil(len(conditionings)/2)
deltas = None
for chunk_index in range(chunk_count):
offset = chunk_index*2
chunk_size = min(2, len(conditionings)-offset)
if chunk_size == 1:
c_in = conditionings[offset]
latents_a = forward_func(x_in[:-1], t_in[:-1], c_in)
latents_b = None
else:
c_in = torch.cat(conditionings[offset:offset+2])
latents_a, latents_b = forward_func(x_in, t_in, c_in).chunk(2)
# first chunk is guaranteed to be 2 entries: uncond_latents + first conditioining
if chunk_index == 0:
uncond_latents = latents_a
deltas = latents_b - uncond_latents
else:
deltas = torch.cat((deltas, latents_a - uncond_latents))
if latents_b is not None:
deltas = torch.cat((deltas, latents_b - uncond_latents))
# merge the weighted deltas together into a single merged delta
per_delta_weights = torch.tensor(weights[1:], dtype=deltas.dtype, device=deltas.device)
normalize = False
if normalize:
per_delta_weights /= torch.sum(per_delta_weights)
reshaped_weights = per_delta_weights.reshape(per_delta_weights.shape + (1, 1, 1))
deltas_merged = torch.sum(deltas * reshaped_weights, dim=0, keepdim=True)
# old_return_value = super().forward(x, sigma, uncond, cond, cond_scale)
# assert(0 == len(torch.nonzero(old_return_value - (uncond_latents + deltas_merged * cond_scale))))
return uncond_latents + deltas_merged * global_guidance_scale