InvokeAI/ldm/simplet2i.py
2022-08-25 15:13:07 -07:00

552 lines
24 KiB
Python

# Copyright (c) 2022 Lincoln D. Stein (https://github.com/lstein)
# Derived from source code carrying the following copyrights
# Copyright (c) 2022 Machine Vision and Learning Group, LMU Munich
# Copyright (c) 2022 Robin Rombach and Patrick Esser and contributors
import torch
import numpy as np
import random
import sys
import os
from omegaconf import OmegaConf
from PIL import Image
from tqdm import tqdm, trange
from itertools import islice
from einops import rearrange, repeat
from torchvision.utils import make_grid
from pytorch_lightning import seed_everything
from torch import autocast
from contextlib import contextmanager, nullcontext
import transformers
import time
import re
import traceback
from ldm.util import instantiate_from_config
from ldm.models.diffusion.ddim import DDIMSampler
from ldm.models.diffusion.plms import PLMSSampler
from ldm.models.diffusion.ksampler import KSampler
from ldm.dream_util import PngWriter
"""Simplified text to image API for stable diffusion/latent diffusion
Example Usage:
from ldm.simplet2i import T2I
# Create an object with default values
t2i = T2I(model = <path> // models/ldm/stable-diffusion-v1/model.ckpt
config = <path> // configs/stable-diffusion/v1-inference.yaml
iterations = <integer> // how many times to run the sampling (1)
batch_size = <integer> // how many images to generate per sampling (1)
steps = <integer> // 50
seed = <integer> // current system time
sampler_name= ['ddim', 'k_dpm_2_a', 'k_dpm_2', 'k_euler_a', 'k_euler', 'k_heun', 'k_lms', 'plms'] // k_lms
grid = <boolean> // false
width = <integer> // image width, multiple of 64 (512)
height = <integer> // image height, multiple of 64 (512)
cfg_scale = <float> // unconditional guidance scale (7.5)
)
# do the slow model initialization
t2i.load_model()
# Do the fast inference & image generation. Any options passed here
# override the default values assigned during class initialization
# Will call load_model() if the model was not previously loaded and so
# may be slow at first.
# The method returns a list of images. Each row of the list is a sub-list of [filename,seed]
results = t2i.prompt2png(prompt = "an astronaut riding a horse",
outdir = "./outputs/samples",
iterations = 3)
for row in results:
print(f'filename={row[0]}')
print(f'seed ={row[1]}')
# Same thing, but using an initial image.
results = t2i.prompt2png(prompt = "an astronaut riding a horse",
outdir = "./outputs/,
iterations = 3,
init_img = "./sketches/horse+rider.png")
for row in results:
print(f'filename={row[0]}')
print(f'seed ={row[1]}')
# Same thing, but we return a series of Image objects, which lets you manipulate them,
# combine them, and save them under arbitrary names
results = t2i.prompt2image(prompt = "an astronaut riding a horse"
outdir = "./outputs/")
for row in results:
im = row[0]
seed = row[1]
im.save(f'./outputs/samples/an_astronaut_riding_a_horse-{seed}.png')
im.thumbnail(100,100).save('./outputs/samples/astronaut_thumb.jpg')
Note that the old txt2img() and img2img() calls are deprecated but will
still work.
"""
class T2I:
"""T2I class
Attributes
----------
model
config
iterations
batch_size
steps
seed
sampler_name
width
height
cfg_scale
latent_channels
downsampling_factor
precision
strength
embedding_path
The vast majority of these arguments default to reasonable values.
"""
def __init__(self,
batch_size=1,
iterations = 1,
steps=50,
seed=None,
cfg_scale=7.5,
weights="models/ldm/stable-diffusion-v1/model.ckpt",
config = "configs/stable-diffusion/v1-inference.yaml",
width=512,
height=512,
sampler_name="klms",
latent_channels=4,
downsampling_factor=8,
ddim_eta=0.0, # deterministic
precision='autocast',
full_precision=False,
strength=0.75, # default in scripts/img2img.py
embedding_path=None,
latent_diffusion_weights=False, # just to keep track of this parameter when regenerating prompt
device='cuda'
):
self.batch_size = batch_size
self.iterations = iterations
self.width = width
self.height = height
self.steps = steps
self.cfg_scale = cfg_scale
self.weights = weights
self.config = config
self.sampler_name = sampler_name
self.latent_channels = latent_channels
self.downsampling_factor = downsampling_factor
self.ddim_eta = ddim_eta
self.precision = precision
self.full_precision = full_precision
self.strength = strength
self.embedding_path = embedding_path
self.model = None # empty for now
self.sampler = None
self.latent_diffusion_weights=latent_diffusion_weights
self.device = device
if seed is None:
self.seed = self._new_seed()
else:
self.seed = seed
transformers.logging.set_verbosity_error()
def prompt2png(self,prompt,outdir,**kwargs):
'''
Takes a prompt and an output directory, writes out the requested number
of PNG files, and returns an array of [[filename,seed],[filename,seed]...]
Optional named arguments are the same as those passed to T2I and prompt2image()
'''
results = self.prompt2image(prompt,**kwargs)
pngwriter = PngWriter(outdir,prompt,kwargs.get('batch_size',self.batch_size))
for r in results:
metadata_str = f'prompt2png("{prompt}" {kwargs} seed={r[1]}' # gets written into the PNG
pngwriter.write_image(r[0],r[1])
return pngwriter.files_written
def txt2img(self,prompt,**kwargs):
outdir = kwargs.get('outdir','outputs/img-samples')
return self.prompt2png(prompt,outdir,**kwargs)
def img2img(self,prompt,**kwargs):
outdir = kwargs.get('outdir','outputs/img-samples')
assert 'init_img' in kwargs,'call to img2img() must include the init_img argument'
return self.prompt2png(prompt,outdir,**kwargs)
def prompt2image(self,
# these are common
prompt,
batch_size=None,
iterations=None,
steps=None,
seed=None,
cfg_scale=None,
ddim_eta=None,
skip_normalize=False,
image_callback=None,
# these are specific to txt2img
width=None,
height=None,
# these are specific to img2img
init_img=None,
strength=None,
variants=None,
**args): # eat up additional cruft
'''
ldm.prompt2image() is the common entry point for txt2img() and img2img()
It takes the following arguments:
prompt // prompt string (no default)
iterations // iterations (1); image count=iterations x batch_size
batch_size // images per iteration (1)
steps // refinement steps per iteration
seed // seed for random number generator
width // width of image, in multiples of 64 (512)
height // height of image, in multiples of 64 (512)
cfg_scale // how strongly the prompt influences the image (7.5) (must be >1)
init_img // path to an initial image - its dimensions override width and height
strength // strength for noising/unnoising init_img. 0.0 preserves image exactly, 1.0 replaces it completely
ddim_eta // image randomness (eta=0.0 means the same seed always produces the same image)
variants // if >0, the 1st generated image will be passed back to img2img to generate the requested number of variants
callback // a function or method that will be called each time an image is generated
To use the callback, define a function of method that receives two arguments, an Image object
and the seed. You can then do whatever you like with the image, including converting it to
different formats and manipulating it. For example:
def process_image(image,seed):
image.save(f{'images/seed.png'})
The callback used by the prompt2png() can be found in ldm/dream_util.py. It contains code
to create the requested output directory, select a unique informative name for each image, and
write the prompt into the PNG metadata.
'''
steps = steps or self.steps
seed = seed or self.seed
width = width or self.width
height = height or self.height
cfg_scale = cfg_scale or self.cfg_scale
ddim_eta = ddim_eta or self.ddim_eta
batch_size = batch_size or self.batch_size
iterations = iterations or self.iterations
strength = strength or self.strength
model = self.load_model() # will instantiate the model or return it from cache
assert cfg_scale>1.0, "CFG_Scale (-C) must be >1.0"
assert 0. <= strength <= 1., 'can only work with strength in [0.0, 1.0]'
w = int(width/64) * 64
h = int(height/64) * 64
if h != height or w != width:
print(f'Height and width must be multiples of 64. Resizing to {h}x{w}')
height = h
width = w
data = [batch_size * [prompt]]
scope = autocast if self.precision=="autocast" else nullcontext
tic = time.time()
results = list()
def prompt_callback(image, seed):
results.append([image, seed])
if image_callback is not None:
image_callback(image, seed)
try:
if init_img:
assert os.path.exists(init_img),f'{init_img}: File not found'
self._img2img(prompt,
data=data,precision_scope=scope,
batch_size=batch_size,iterations=iterations,
steps=steps,seed=seed,cfg_scale=cfg_scale,ddim_eta=ddim_eta,
skip_normalize=skip_normalize,
init_img=init_img,strength=strength,variants=variants,
callback=prompt_callback)
else:
self._txt2img(prompt,
data=data,precision_scope=scope,
batch_size=batch_size,iterations=iterations,
steps=steps,seed=seed,cfg_scale=cfg_scale,ddim_eta=ddim_eta,
skip_normalize=skip_normalize,
width=width,height=height,
callback=prompt_callback)
except KeyboardInterrupt:
print('*interrupted*')
print('Partial results will be returned; if --grid was requested, nothing will be returned.')
except RuntimeError as e:
print(str(e))
toc = time.time()
print(f'{len(results)} images generated in',"%4.2fs"% (toc-tic))
return results
@torch.no_grad()
def _txt2img(self,prompt,
data,precision_scope,
batch_size,iterations,
steps,seed,cfg_scale,ddim_eta,
skip_normalize,
width,height,
callback): # the callback is called each time a new Image is generated
"""
Generate an image from the prompt, writing iteration images into the outdir
The output is a list of lists in the format: [[image1,seed1], [image2,seed2],...]
"""
sampler = self.sampler
images = list()
image_count = 0
# Gawd. Too many levels of indent here. Need to refactor into smaller routines!
with precision_scope(self.device.type), self.model.ema_scope():
all_samples = list()
for n in trange(iterations, desc="Sampling"):
seed_everything(seed)
for prompts in tqdm(data, desc="data", dynamic_ncols=True):
uc = None
if cfg_scale != 1.0:
uc = self.model.get_learned_conditioning(batch_size * [""])
if isinstance(prompts, tuple):
prompts = list(prompts)
# weighted sub-prompts
subprompts,weights = T2I._split_weighted_subprompts(prompts[0])
if len(subprompts) > 1:
# i dont know if this is correct.. but it works
c = torch.zeros_like(uc)
# get total weight for normalizing
totalWeight = sum(weights)
# normalize each "sub prompt" and add it
for i in range(0,len(subprompts)):
weight = weights[i]
if not skip_normalize:
weight = weight / totalWeight
c = torch.add(c,self.model.get_learned_conditioning(subprompts[i]), alpha=weight)
else: # just standard 1 prompt
c = self.model.get_learned_conditioning(prompts)
shape = [self.latent_channels, height // self.downsampling_factor, width // self.downsampling_factor]
samples_ddim, _ = sampler.sample(S=steps,
conditioning=c,
batch_size=batch_size,
shape=shape,
verbose=False,
unconditional_guidance_scale=cfg_scale,
unconditional_conditioning=uc,
eta=ddim_eta)
x_samples_ddim = self.model.decode_first_stage(samples_ddim)
x_samples_ddim = torch.clamp((x_samples_ddim + 1.0) / 2.0, min=0.0, max=1.0)
for x_sample in x_samples_ddim:
x_sample = 255. * rearrange(x_sample.cpu().numpy(), 'c h w -> h w c')
image = Image.fromarray(x_sample.astype(np.uint8))
images.append([image,seed])
if callback is not None:
callback(image,seed)
seed = self._new_seed()
return images
@torch.no_grad()
def _img2img(self,prompt,
data,precision_scope,
batch_size,iterations,
steps,seed,cfg_scale,ddim_eta,
skip_normalize,
init_img,strength,variants,
callback):
"""
Generate an image from the prompt and the initial image, writing iteration images into the outdir
The output is a list of lists in the format: [[image,seed1], [image,seed2],...]
"""
# PLMS sampler not supported yet, so ignore previous sampler
if self.sampler_name!='ddim':
print(f"sampler '{self.sampler_name}' is not yet supported. Using DDM sampler")
sampler = DDIMSampler(self.model, device=self.device)
else:
sampler = self.sampler
init_image = self._load_img(init_img).to(self.device)
init_image = repeat(init_image, '1 ... -> b ...', b=batch_size)
with precision_scope(self.device.type):
init_latent = self.model.get_first_stage_encoding(self.model.encode_first_stage(init_image)) # move to latent space
sampler.make_schedule(ddim_num_steps=steps, ddim_eta=ddim_eta, verbose=False)
t_enc = int(strength * steps)
# print(f"target t_enc is {t_enc} steps")
images = list()
with precision_scope(self.device.type), self.model.ema_scope():
all_samples = list()
for n in trange(iterations, desc="Sampling"):
seed_everything(seed)
for prompts in tqdm(data, desc="data", dynamic_ncols=True):
uc = None
if cfg_scale != 1.0:
uc = self.model.get_learned_conditioning(batch_size * [""])
if isinstance(prompts, tuple):
prompts = list(prompts)
# weighted sub-prompts
subprompts,weights = T2I._split_weighted_subprompts(prompts[0])
if len(subprompts) > 1:
# i dont know if this is correct.. but it works
c = torch.zeros_like(uc)
# get total weight for normalizing
totalWeight = sum(weights)
# normalize each "sub prompt" and add it
for i in range(0,len(subprompts)):
weight = weights[i]
if not skip_normalize:
weight = weight / totalWeight
c = torch.add(c,self.model.get_learned_conditioning(subprompts[i]), alpha=weight)
else: # just standard 1 prompt
c = self.model.get_learned_conditioning(prompts)
# encode (scaled latent)
z_enc = sampler.stochastic_encode(init_latent, torch.tensor([t_enc]*batch_size).to(self.device))
# decode it
samples = sampler.decode(z_enc, c, t_enc, unconditional_guidance_scale=cfg_scale,
unconditional_conditioning=uc,)
x_samples = self.model.decode_first_stage(samples)
x_samples = torch.clamp((x_samples + 1.0) / 2.0, min=0.0, max=1.0)
for x_sample in x_samples:
x_sample = 255. * rearrange(x_sample.cpu().numpy(), 'c h w -> h w c')
image = Image.fromarray(x_sample.astype(np.uint8))
images.append([image,seed])
if callback is not None:
callback(image,seed)
seed = self._new_seed()
return images
def _new_seed(self):
self.seed = random.randrange(0,np.iinfo(np.uint32).max)
return self.seed
def load_model(self):
""" Load and initialize the model from configuration variables passed at object creation time """
if self.model is None:
seed_everything(self.seed)
try:
config = OmegaConf.load(self.config)
self.device = torch.device(self.device) if torch.cuda.is_available() else torch.device("cpu")
model = self._load_model_from_config(config,self.weights)
if self.embedding_path is not None:
model.embedding_manager.load(self.embedding_path)
self.model = model.to(self.device)
# model.to doesn't change the cond_stage_model.device used to move the tokenizer output, so set it here
self.model.cond_stage_model.device = self.device
except AttributeError:
raise SystemExit
msg = f'setting sampler to {self.sampler_name}'
if self.sampler_name=='plms':
self.sampler = PLMSSampler(self.model, device=self.device)
elif self.sampler_name == 'ddim':
self.sampler = DDIMSampler(self.model, device=self.device)
elif self.sampler_name == 'k_dpm_2_a':
self.sampler = KSampler(self.model, 'dpm_2_ancestral', device=self.device)
elif self.sampler_name == 'k_dpm_2':
self.sampler = KSampler(self.model, 'dpm_2', device=self.device)
elif self.sampler_name == 'k_euler_a':
self.sampler = KSampler(self.model, 'euler_ancestral', device=self.device)
elif self.sampler_name == 'k_euler':
self.sampler = KSampler(self.model, 'euler', device=self.device)
elif self.sampler_name == 'k_heun':
self.sampler = KSampler(self.model, 'heun', device=self.device)
elif self.sampler_name == 'k_lms':
self.sampler = KSampler(self.model, 'lms', device=self.device)
else:
msg = f'unsupported sampler {self.sampler_name}, defaulting to plms'
self.sampler = PLMSSampler(self.model, device=self.device)
print(msg)
return self.model
def _load_model_from_config(self, config, ckpt):
print(f"Loading model from {ckpt}")
pl_sd = torch.load(ckpt, map_location="cpu")
# if "global_step" in pl_sd:
# print(f"Global Step: {pl_sd['global_step']}")
sd = pl_sd["state_dict"]
model = instantiate_from_config(config.model)
m, u = model.load_state_dict(sd, strict=False)
model.to(self.device)
model.eval()
if self.full_precision:
print('Using slower but more accurate full-precision math (--full_precision)')
else:
print('Using half precision math. Call with --full_precision to use slower but more accurate full precision.')
model.half()
return model
def _load_img(self,path):
image = Image.open(path).convert("RGB")
w, h = image.size
print(f"loaded input image of size ({w}, {h}) from {path}")
w, h = map(lambda x: x - x % 32, (w, h)) # resize to integer multiple of 32
image = image.resize((w, h), resample=Image.Resampling.LANCZOS)
image = np.array(image).astype(np.float32) / 255.0
image = image[None].transpose(0, 3, 1, 2)
image = torch.from_numpy(image)
return 2.*image - 1.
def _split_weighted_subprompts(text):
"""
grabs all text up to the first occurrence of ':'
uses the grabbed text as a sub-prompt, and takes the value following ':' as weight
if ':' has no value defined, defaults to 1.0
repeats until no text remaining
"""
remaining = len(text)
prompts = []
weights = []
while remaining > 0:
if ":" in text:
idx = text.index(":") # first occurrence from start
# grab up to index as sub-prompt
prompt = text[:idx]
remaining -= idx
# remove from main text
text = text[idx+1:]
# find value for weight
if " " in text:
idx = text.index(" ") # first occurence
else: # no space, read to end
idx = len(text)
if idx != 0:
try:
weight = float(text[:idx])
except: # couldn't treat as float
print(f"Warning: '{text[:idx]}' is not a value, are you missing a space?")
weight = 1.0
else: # no value found
weight = 1.0
# remove from main text
remaining -= idx
text = text[idx+1:]
# append the sub-prompt and its weight
prompts.append(prompt)
weights.append(weight)
else: # no : found
if len(text) > 0: # there is still text though
# take remainder as weight 1
prompts.append(text)
weights.append(1.0)
remaining = 0
return prompts, weights