fix another bug thanks to @xiankgx

README.md

@@ -647,11 +647,12 @@ Once built, images will be saved to the same directory the command is invoked
 - [x] use attention-based upsampling https://arxiv.org/abs/2112.11435
 - [x] use inheritance just this once for sharing logic between decoder and prior network ddpms
 - [x] bring in vit-vqgan https://arxiv.org/abs/2110.04627 for the latent diffusion
-- [ ] abstract interface for CLIP adapter class, so other CLIPs can be brought in
+- [x] abstract interface for CLIP adapter class, so other CLIPs can be brought in
 - [ ] become an expert with unets, cleanup unet code, make it fully configurable, port all learnings over to https://github.com/lucidrains/x-unet
 - [ ] copy the cascading ddpm code to a separate repo (perhaps https://github.com/lucidrains/denoising-diffusion-pytorch) as the main contribution of dalle2 really is just the prior network
 - [ ] transcribe code to Jax, which lowers the activation energy for distributed training, given access to TPUs
 - [ ] train on a toy task, offer in colab
+- [ ] think about how best to design a declarative training config that handles preencoding for prior and training of multiple networks in decoder
 - [ ] extend diffusion head to use diffusion-gan (potentially using lightweight-gan) to speed up inference
 - [ ] bring in tools to train vqgan-vae
 

dalle2_pytorch/dalle2_pytorch.py

@@ -7,6 +7,7 @@ from contextlib import contextmanager
 import torch
 import torch.nn.functional as F
 from torch import nn, einsum
+import torchvision.transforms as T
 
 from einops import rearrange, repeat
 from einops.layers.torch import Rearrange
@@ -89,6 +90,59 @@ def resize_image_to(t, image_size, mode = 'bilinear'): # take a look at https://
 
     return F.interpolate(t, size = shape, mode = mode, align_corners = False)
 
+# clip related adapters
+
+class BaseClipAdapter(nn.Module):
+    def __init__(self, clip):
+        super().__init__()
+        self.clip = clip
+
+    @property
+    def dim_latent(self):
+        raise NotImplementedError
+
+    @property
+    def image_size(self):
+        raise NotImplementedError
+
+    @property
+    def image_channels(self):
+        raise NotImplementedError
+
+    def embed_text(self, text):
+        raise NotImplementedError
+
+    def embed_image(self, image):
+        raise NotImplementedError
+
+class XClipAdapter(BaseClipAdapter):
+    @property
+    def dim_latent(self):
+        return self.clip.dim_latent
+
+    @property
+    def image_size(self):
+        return self.clip.image_size
+
+    @property
+    def image_channels(self):
+        return self.clip.image_channels
+
+    @torch.no_grad()
+    def embed_text(self, text):
+        encoder_output = self.clip.text_transformer(text)
+        text_cls, text_encodings = encoder_output[:, 0], encoder_output[:, 1:]
+        text_embed = self.clip.to_text_latent(text_cls)
+        return l2norm(text_embed), text_encodings
+
+    @torch.no_grad()
+    def embed_image(self, image):
+        image = resize_image_to(image, self.image_size)
+        encoder_output = self.clip.visual_transformer(image)
+        image_cls, image_encodings = encoder_output[:, 0], encoder_output[:, 1:]
+        image_embed = self.clip.to_visual_latent(image_cls)
+        return l2norm(image_embed), image_encodings
+
 # classifier free guidance functions
 
 def prob_mask_like(shape, prob, device):
@@ -169,7 +223,18 @@ class BaseGaussianDiffusion(nn.Module):
 
         timesteps, = betas.shape
         self.num_timesteps = int(timesteps)
+
+        if loss_type == 'l1':
+            loss_fn = F.l1_loss
+        elif loss_type == 'l2':
+            loss_fn = F.mse_loss
+        elif loss_type == 'huber':
+            loss_fn = F.smooth_l1_loss
+        else:
+            raise NotImplementedError()
+
         self.loss_type = loss_type
+        self.loss_fn = loss_fn
 
         self.register_buffer('betas', betas)
         self.register_buffer('alphas_cumprod', alphas_cumprod)
@@ -593,7 +658,10 @@ class DiffusionPrior(BaseGaussianDiffusion):
         )
 
         if exists(clip):
-            assert isinstance(clip, CLIP)
+            if isinstance(clip, CLIP):
+                clip = XClipAdapter(clip)
+
+            assert isinstance(clip, BaseClipAdapter)
             freeze_model_and_make_eval_(clip)
             self.clip = clip
         else:
@@ -610,29 +678,6 @@ class DiffusionPrior(BaseGaussianDiffusion):
         self.predict_x_start = predict_x_start
         # in paper, they do not predict the noise, but predict x0 directly for image embedding, claiming empirically better results. I'll just offer both.
 
-    @torch.no_grad()
-    def get_image_embed(self, image):
-        assert exists(self.clip)
-
-        image_encoding = self.clip.visual_transformer(image)
-        image_cls = image_encoding[:, 0]
-        image_embed = self.clip.to_visual_latent(image_cls)
-        return l2norm(image_embed)
-
-    @torch.no_grad()
-    def get_text_cond(self, text):
-        assert exists(self.clip)
-
-        text_encodings = self.clip.text_transformer(text)
-        text_cls, text_encodings = text_encodings[:, 0], text_encodings[:, 1:]
-        text_embed = self.clip.to_text_latent(text_cls)
-        text_embed = l2norm(text_embed)
-
-        if not self.condition_on_text_encodings:            
-            return dict(text_embed = text_embed)
-
-        return dict(text_encodings = text_encodings, text_embed = text_embed, mask = text != 0)
-
     def p_mean_variance(self, x, t, text_cond, clip_denoised: bool):
         pred = self.net(x, t, **text_cond)
 
@@ -669,29 +714,21 @@ class DiffusionPrior(BaseGaussianDiffusion):
             img = self.p_sample(img, torch.full((b,), i, device = device, dtype = torch.long), text_cond = text_cond)
         return img
 
-    def p_losses(self, image_embed, t, text_cond, noise = None):
+    def p_losses(self, image_embed, times, text_cond, noise = None):
         noise = default(noise, lambda: torch.randn_like(image_embed))
 
-        image_embed_noisy = self.q_sample(x_start = image_embed, t = t, noise = noise)
+        image_embed_noisy = self.q_sample(x_start = image_embed, t = times, noise = noise)
 
-        x_recon = self.net(
+        pred = self.net(
             image_embed_noisy,
-            t,
+            times,
             cond_drop_prob = self.cond_drop_prob,
             **text_cond
         )
 
-        to_predict = noise if not self.predict_x_start else image_embed
+        target = noise if not self.predict_x_start else image_embed
-
-        if self.loss_type == 'l1':
-            loss = F.l1_loss(to_predict, x_recon)
-        elif self.loss_type == 'l2':
-            loss = F.mse_loss(to_predict, x_recon)
-        elif self.loss_type == "huber":
-            loss = F.smooth_l1_loss(to_predict, x_recon)
-        else:
-            raise NotImplementedError()
 
+        loss = self.loss_fn(pred, target)
         return loss
 
     @torch.no_grad()
@@ -704,7 +741,12 @@ class DiffusionPrior(BaseGaussianDiffusion):
         batch_size = text.shape[0]
         image_embed_dim = self.image_embed_dim
 
-        text_cond = self.get_text_cond(text)
+        text_embed, text_encodings = self.clip.embed_text(text)
+
+        text_cond = dict(text_embed = text_embed)
+
+        if self.condition_on_text_encodings:
+            text_cond = {**text_cond, 'text_encodings': text_encodings, 'mask': text != 0}
 
         image_embeds = self.p_sample_loop((batch_size, image_embed_dim), text_cond = text_cond)
         text_embeds = text_cond['text_embed']
@@ -736,18 +778,19 @@ class DiffusionPrior(BaseGaussianDiffusion):
         assert not (self.condition_on_text_encodings and (not exists(text_encodings) and not exists(text))), 'text encodings must be present if you specified you wish to condition on it on initialization'
 
         if exists(image):
-            image_embed = self.get_image_embed(image)
+            image_embed, _ = self.clip.embed_image(image)
 
         # calculate text conditionings, based on what is passed in
 
         if exists(text):
-            text_cond = self.get_text_cond(text)
+            text_embed, text_encodings = self.clip.embed_text(text)
-        else:
+            text_mask = text != 0
-            text_cond = dict(
+
-                text_embed = text_embed,
+        text_cond = dict(text_embed = text_embed)
-                text_encodings = text_encodings,
+
-                mask = text_mask
+        if self.condition_on_text_encodings:
-            )
+            assert exists(text_encodings), 'text encodings must be present for diffusion prior if specified'
+            text_cond = {**text_cond, 'text_encodings': text_encodings, 'mask': text_mask}
 
         # timestep conditioning from ddpm
 
@@ -756,8 +799,7 @@ class DiffusionPrior(BaseGaussianDiffusion):
 
         # calculate forward loss
 
-        loss = self.p_losses(image_embed, times, text_cond = text_cond, *args, **kwargs)
+        return self.p_losses(image_embed, times, text_cond = text_cond, *args, **kwargs)
-        return loss
 
 # decoder
 
@@ -1027,13 +1069,14 @@ class Unet(nn.Module):
         self,
         *,
         lowres_cond,
-        channels
+        channels,
+        cond_on_image_embeds
     ):
-        if lowres_cond == self.lowres_cond and channels == self.channels:
+        if lowres_cond == self.lowres_cond and channels == self.channels and cond_on_image_embeds == self.cond_on_image_embeds:
             return self
 
-        updated_kwargs = {**self._locals, 'lowres_cond': lowres_cond, 'channels': channels}
+        updated_kwargs = {'lowres_cond': lowres_cond, 'channels': channels, 'cond_on_image_embeds': cond_on_image_embeds}
-        return self.__class__(**updated_kwargs)
+        return self.__class__(**{**self._locals, **updated_kwargs})
 
     def forward_with_cond_scale(
         self,
@@ -1170,7 +1213,7 @@ class LowresConditioner(nn.Module):
         target_image_size = cast_tuple(target_image_size, 2)
 
         if self.training and self.downsample_first and exists(downsample_image_size):
-            cond_fmap = resize_image_to(cond_fmap, target_image_size, mode = self.cond_upsample_mode)
+            cond_fmap = resize_image_to(cond_fmap, downsample_image_size, mode = self.cond_upsample_mode)
 
         if self.training:
             # when training, blur the low resolution conditional image
@@ -1208,8 +1251,12 @@ class Decoder(BaseGaussianDiffusion):
             loss_type = loss_type
         )
 
-        assert isinstance(clip, CLIP)
+        if isinstance(clip, CLIP):
+            clip = XClipAdapter(clip)
+
         freeze_model_and_make_eval_(clip)
+        assert isinstance(clip, BaseClipAdapter)
+
         self.clip = clip
         self.clip_image_size = clip.image_size
         self.channels = clip.image_channels
@@ -1236,6 +1283,7 @@ class Decoder(BaseGaussianDiffusion):
 
             one_unet = one_unet.cast_model_parameters(
                 lowres_cond = not is_first,
+                cond_on_image_embeds = is_first,
                 channels = unet_channels
             )
 
@@ -1290,10 +1338,6 @@ class Decoder(BaseGaussianDiffusion):
         yield
         unet.cpu()
 
-    @torch.no_grad()
-    def get_text_encodings(self, text):
-        text_encodings = self.clip.text_transformer(text)
-        return text_encodings[:, 1:]
 
     @torch.no_grad()
     def get_image_embed(self, image):
@@ -1347,14 +1391,14 @@ class Decoder(BaseGaussianDiffusion):
 
         return img
 
-    def p_losses(self, unet, x_start, t, *, image_embed, lowres_cond_img = None, text_encodings = None, predict_x_start = False, noise = None):
+    def p_losses(self, unet, x_start, times, *, image_embed, lowres_cond_img = None, text_encodings = None, predict_x_start = False, noise = None):
         noise = default(noise, lambda: torch.randn_like(x_start))
 
-        x_noisy = self.q_sample(x_start = x_start, t = t, noise = noise)
+        x_noisy = self.q_sample(x_start = x_start, t = times, noise = noise)
 
-        x_recon = unet(
+        pred = unet(
             x_noisy,
-            t,
+            times,
             image_embed = image_embed,
             text_encodings = text_encodings,
             lowres_cond_img = lowres_cond_img,
@@ -1363,15 +1407,7 @@ class Decoder(BaseGaussianDiffusion):
 
         target = noise if not predict_x_start else x_start
 
-        if self.loss_type == 'l1':
+        loss = self.loss_fn(pred, target)
-            loss = F.l1_loss(target, x_recon)
-        elif self.loss_type == 'l2':
-            loss = F.mse_loss(target, x_recon)
-        elif self.loss_type == "huber":
-            loss = F.smooth_l1_loss(target, x_recon)
-        else:
-            raise NotImplementedError()
-
         return loss
 
     @torch.no_grad()
@@ -1379,9 +1415,12 @@ class Decoder(BaseGaussianDiffusion):
     def sample(self, image_embed, text = None, cond_scale = 1.):
         batch_size = image_embed.shape[0]
 
-        text_encodings = self.get_text_encodings(text) if exists(text) else None
+        text_encodings = None
+        if exists(text):
+            _, text_encodings = self.clip.embed_text(text)
 
         assert not (self.condition_on_text_encodings and not exists(text_encodings)), 'text or text encodings must be passed into decoder if specified'
+        assert not (not self.condition_on_text_encodings and exists(text_encodings)), 'decoder specified not to be conditioned on text, yet it is presented'
 
         img = None
 
@@ -1442,11 +1481,14 @@ class Decoder(BaseGaussianDiffusion):
         times = torch.randint(0, self.num_timesteps, (b,), device = device, dtype = torch.long)
 
         if not exists(image_embed):
-            image_embed = self.get_image_embed(image)
+            image_embed, _ = self.clip.embed_image(image)
 
-        text_encodings = self.get_text_encodings(text) if exists(text) and not exists(text_encodings) else None
+        text_encodings = None
+        if exists(text) and not exists(text_encodings):
+            _, text_encodings = self.clip.embed_text(text)
 
         assert not (self.condition_on_text_encodings and not exists(text_encodings)), 'text or text encodings must be passed into decoder if specified'
+        assert not (not self.condition_on_text_encodings and exists(text_encodings)), 'decoder specified not to be conditioned on text, yet it is presented'
 
         lowres_cond_img = self.to_lowres_cond(image, target_image_size = target_image_size, downsample_image_size = self.image_sizes[unet_index - 1]) if unet_number > 1 else None
         image = resize_image_to(image, target_image_size)
@@ -1479,12 +1521,15 @@ class DALLE2(nn.Module):
         self.prior_num_samples = prior_num_samples
         self.decoder_need_text_cond = self.decoder.condition_on_text_encodings
 
+        self.to_pil = T.ToPILImage()
+
     @torch.no_grad()
     @eval_decorator
     def forward(
         self,
         text,
-        cond_scale = 1.
+        cond_scale = 1.,
+        return_pil_images = False
     ):
         device = next(self.parameters()).device
         one_text = isinstance(text, str) or (not is_list_str(text) and text.shape[0] == 1)
@@ -1498,7 +1543,11 @@ class DALLE2(nn.Module):
         text_cond = text if self.decoder_need_text_cond else None
         images = self.decoder.sample(image_embed, text = text_cond, cond_scale = cond_scale)
 
+        if return_pil_images:
+            images = list(map(self.to_pil, images.unbind(dim = 0)))
+
         if one_text:
             return images[0]
 
         return images
+

dalle2_pytorch/vqgan_vae.py

@@ -545,6 +545,7 @@ class VQGanVAE(nn.Module):
         l2_recon_loss = False,
         use_hinge_loss = True,
         vgg = None,
+        vq_codebook_dim = 256,
         vq_codebook_size = 512,
         vq_decay = 0.8,
         vq_commitment_weight = 1.,
@@ -579,6 +580,7 @@ class VQGanVAE(nn.Module):
 
         self.vq = VQ(
             dim = self.enc_dec.encoded_dim,
+            codebook_dim = vq_codebook_dim,
             codebook_size = vq_codebook_size,
             decay = vq_decay,
             commitment_weight = vq_commitment_weight,

setup.py

@@ -10,7 +10,7 @@ setup(
       'dream = dalle2_pytorch.cli:dream'
     ],
   },
-  version = '0.0.56',
+  version = '0.0.65',
   license='MIT',
   description = 'DALL-E 2',
   author = 'Phil Wang',