img2img is now working; small refactoring of grid code in simplet2i.py

ldm/simplet2i.py

@@ -26,23 +26,22 @@ t2i.load_model()
 # override the default values assigned during class initialization
 # Will call load_model() if the model was not previously loaded.
 # The method returns a list of images. Each row of the list is a sub-list of [filename,seed]
-results = t2i.txt2img(prompt = <string>           // required
+results = t2i.txt2img(prompt = "an astronaut riding a horse"
-                      outdir = <path>             // the remaining option arguments override constructur value when present
+                      outdir = "./outputs/txt2img-samples)
-                      iterations  = <integer>
+            )
-                      batch       = <integer>
-                      steps       = <integer>
-                      seed        = <integer>     
-                      sampler     = ['ddim','plms']
-                      grid        = <boolean>
-                      width       = <integer> 
-                      height      = <integer>
-                      cfg_scale   = <float>
-            ) -> boolean
 
 for row in results:
     print(f'filename={row[0]}')
     print(f'seed    ={row[1]}')
+
+# Same thing, but using an initial image.
+results = t2i.img2img(prompt   = "an astronaut riding a horse"
+                      outdir   = "./outputs/img2img-samples"
+                      init_img = "./sketches/horse+rider.png")
                  
+for row in results:
+    print(f'filename={row[0]}')
+    print(f'seed    ={row[1]}')
 """
 
 import torch
@@ -54,7 +53,7 @@ from omegaconf import OmegaConf
 from PIL import Image
 from tqdm import tqdm, trange
 from itertools import islice
-from einops import rearrange
+from einops import rearrange, repeat
 from torchvision.utils import make_grid
 from pytorch_lightning import seed_everything
 from torch import autocast
@@ -87,6 +86,7 @@ class T2I:
     latent_channels
     downsampling_factor
     precision
+    strength
 """
     def __init__(self,
                  outdir="outputs/txt2img-samples",
@@ -106,7 +106,8 @@ class T2I:
                  downsampling_factor=8,
                  ddim_eta=0.0,  # deterministic
                  fixed_code=False,
-                 precision='autocast'
+                 precision='autocast',
+                 strength=0.75 # default in scripts/img2img.py
     ):
         self.outdir     = outdir
         self.batch      = batch
@@ -124,15 +125,17 @@ class T2I:
         self.downsampling_factor = downsampling_factor
         self.ddim_eta            = ddim_eta
         self.precision           = precision
+        self.strength            = strength
         self.model      = None     # empty for now
         self.sampler    = None
         if seed is None:
             self.seed = self._new_seed()
         else:
             self.seed = seed
+
     def txt2img(self,prompt,outdir=None,batch=None,iterations=None,
                 steps=None,seed=None,grid=None,individual=None,width=None,height=None,
-                cfg_scale=None,ddim_eta=None):
+                cfg_scale=None,ddim_eta=None,strength=None,init_img=None):
         """
         Generate an image from the prompt, writing iteration images into the outdir
         The output is a list of lists in the format: [[filename1,seed1], [filename2,seed2],...]
@@ -146,6 +149,7 @@ class T2I:
         ddim_eta   = ddim_eta   or self.ddim_eta
         batch      = batch or self.batch
         iterations = iterations or self.iterations
+        strength   = strength   or self.strength     # not actually used here, but preserved for code refactoring
 
         model = self.load_model()  # will instantiate the model or return it from cache
 
@@ -218,24 +222,146 @@ class T2I:
                         seed = self._new_seed()
  
                     if grid:
-                        n_rows = batch if batch>1 else int(math.sqrt(batch * iterations))
+                        images = self._make_grid(samples=all_samples,
-                        # save as grid
+                                                 seeds=seeds,
-                        grid = torch.stack(all_samples, 0)
+                                                 batch_size=batch,
-                        grid = rearrange(grid, 'n b c h w -> (n b) c h w')
+                                                 iterations=iterations,
-                        grid = make_grid(grid, nrow=n_rows)
+                                                 outdir=outdir)
-
-                        # to image
-                        grid = 255. * rearrange(grid, 'c h w -> h w c').cpu().numpy()
-                        filename = os.path.join(outdir, f"{base_count:05}.png")
-                        Image.fromarray(grid.astype(np.uint8)).save(filename)
-                        for s in seeds:
-                            images.append([filename,s])
 
         toc = time.time()
         print(f'{batch * iterations} images generated in',"%4.2fs"% (toc-tic))
 
         return images
         
+    # There is lots of shared code between this and txt2img and should be refactored.
+    def img2img(self,prompt,outdir=None,init_img=None,batch=None,iterations=None,
+                steps=None,seed=None,grid=None,individual=None,width=None,height=None,
+                cfg_scale=None,ddim_eta=None,strength=None):
+        """
+        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: [[filename1,seed1], [filename2,seed2],...]
+        """
+        outdir     = outdir     or self.outdir
+        steps      = steps      or self.steps
+        seed       = seed       or self.seed
+        cfg_scale  = cfg_scale  or self.cfg_scale
+        ddim_eta   = ddim_eta   or self.ddim_eta
+        batch      = batch      or self.batch
+        iterations = iterations or self.iterations
+        strength   = strength   or self.strength
+
+        if init_img is None:
+            print("no init_img provided!")
+            return []
+
+        model = self.load_model()  # will instantiate the model or return it from cache
+
+        # grid and individual are mutually exclusive, with individual taking priority.
+        # not necessary, but needed for compatability with dream bot
+        if (grid is None):
+            grid = self.grid
+        if individual:
+            grid = False
+        
+        data = [batch * [prompt]]
+
+        # 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(model)
+        else:
+            sampler = self.sampler
+
+        # make directories and establish names for the output files
+        os.makedirs(outdir, exist_ok=True)
+        base_count = len(os.listdir(outdir))-1
+
+        assert os.path.isfile(init_img)
+        init_image = self._load_img(init_img).to(self.device)
+        init_image = repeat(init_image, '1 ... -> b ...', b=batch)
+        init_latent = model.get_first_stage_encoding(model.encode_first_stage(init_image))  # move to latent space
+
+        sampler.make_schedule(ddim_num_steps=steps, ddim_eta=ddim_eta, verbose=False)
+
+        try:
+            assert 0. <= strength <= 1., 'can only work with strength in [0.0, 1.0]'
+        except AssertionError:
+            print(f"strength must be between 0.0 and 1.0, but received value {strength}")
+            return []
+        
+        t_enc = int(strength * steps)
+        print(f"target t_enc is {t_enc} steps")
+
+        precision_scope = autocast if self.precision=="autocast" else nullcontext
+        images = list()
+        seeds  = list()
+
+        tic    = time.time()
+        
+        with torch.no_grad():
+            with precision_scope("cuda"):
+                with 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 = model.get_learned_conditioning(batch * [""])
+                            if isinstance(prompts, tuple):
+                                prompts = list(prompts)
+                            c = model.get_learned_conditioning(prompts)
+
+                            # encode (scaled latent)
+                            z_enc = sampler.stochastic_encode(init_latent, torch.tensor([t_enc]*batch).to(self.device))
+                            # decode it
+                            samples = sampler.decode(z_enc, c, t_enc, unconditional_guidance_scale=cfg_scale,
+                                                     unconditional_conditioning=uc,)
+
+                            x_samples = model.decode_first_stage(samples)
+                            x_samples = torch.clamp((x_samples + 1.0) / 2.0, min=0.0, max=1.0)
+
+                            if not grid:
+                                for x_sample in x_samples:
+                                    x_sample = 255. * rearrange(x_sample.cpu().numpy(), 'c h w -> h w c')
+                                    filename = os.path.join(outdir, f"{base_count:05}.png")
+                                    Image.fromarray(x_sample.astype(np.uint8)).save(filename)
+                                    images.append([filename,seed])
+                                    base_count += 1
+                            else:
+                                all_samples.append(x_samples)
+                                seeds.append(seed)
+
+                        seed = self._new_seed()
+
+                    if grid:
+                        images = self._make_grid(samples=all_samples,
+                                                 seeds=seeds,
+                                                 batch_size=batch,
+                                                 iterations=iterations,
+                                                 outdir=outdir)
+
+        toc = time.time()
+        print(f'{batch * iterations} images generated in',"%4.2fs"% (toc-tic))
+
+        return images
+
+    def _make_grid(self,samples,seeds,batch_size,iterations,outdir):
+        images = list()
+        base_count = len(os.listdir(outdir))-1
+        n_rows = batch_size if batch_size>1 else int(math.sqrt(batch_size * iterations))
+        # save as grid
+        grid = torch.stack(samples, 0)
+        grid = rearrange(grid, 'n b c h w -> (n b) c h w')
+        grid = make_grid(grid, nrow=n_rows)
+
+        # to image
+        grid = 255. * rearrange(grid, 'c h w -> h w c').cpu().numpy()
+        filename = os.path.join(outdir, f"{base_count:05}.png")
+        Image.fromarray(grid.astype(np.uint8)).save(filename)
+        for s in seeds:
+            images.append([filename,s])
+        return images
 
     def _new_seed(self):
         self.seed = random.randrange(0,np.iinfo(np.uint32).max)
@@ -277,3 +403,13 @@ class T2I:
         model.eval()
         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.

scripts/dream.py

@@ -92,7 +92,10 @@ def main_loop(t2i,parser,log):
             print("Try again with a prompt!")
             continue
 
-        results = t2i.txt2img(**vars(opt))
+        if opt.init_img is None:
+            results = t2i.txt2img(**vars(opt))
+        else:
+            results = t2i.img2img(**vars(opt))
         print("Outputs:")
         write_log_message(opt,switches,results,log)
 
@@ -161,9 +164,11 @@ def create_cmd_parser():
     parser.add_argument('-b','--batch',type=int,default=1,help="number of images to produce per sampling (currently broken)")
     parser.add_argument('-W','--width',type=int,help="image width, multiple of 64")
     parser.add_argument('-H','--height',type=int,help="image height, multiple of 64")
-    parser.add_argument('-C','--cfg_scale',type=float,help="prompt configuration scale (7.5)")
+    parser.add_argument('-C','--cfg_scale',default=7.5,type=float,help="prompt configuration scale")
     parser.add_argument('-g','--grid',action='store_true',help="generate a grid")
     parser.add_argument('-i','--individual',action='store_true',help="generate individual files (default)")
+    parser.add_argument('-I','--init_img',type=str,help="path to input image (supersedes width and height)")
+    parser.add_argument('-f','--strength',default=0.75,type=float,help="strength for noising/unnoising. 0.0 preserves image exactly, 1.0 replaces it completely")
     return parser
 
 def load_history():