use inference mode whenever possible, cleanup

* Update train_diffusion_prior.py

* Delete train_diffusion_prior.py

* Cosine similarity logging.

* Update train_diffusion_prior.py

* Report Cosine metrics every N steps.

README.md

@@ -10,7 +10,7 @@ The main novelty seems to be an extra layer of indirection with the prior networ
 
 This model is SOTA for text-to-image for now.
 
-Please join <a href="https://discord.gg/xBPBXfcFHd"><img alt="Join us on Discord" src="https://img.shields.io/discord/823813159592001537?color=5865F2&logo=discord&logoColor=white"></a> if you are interested in helping out with the replication
+Please join <a href="https://discord.gg/xBPBXfcFHd"><img alt="Join us on Discord" src="https://img.shields.io/discord/823813159592001537?color=5865F2&logo=discord&logoColor=white"></a> if you are interested in helping out with the replication with the <a href="https://laion.ai/">LAION</a> community | <a href="https://www.youtube.com/watch?v=AIOE1l1W0Tw">Yannic Interview</a>
 
 There was enough interest for a <a href="https://github.com/lucidrains/dalle2-jax">Jax version</a>. I will also eventually extend this to <a href="https://github.com/lucidrains/dalle2-video">text to video</a>, once the repository is in a good place.
 
@@ -821,7 +821,9 @@ Once built, images will be saved to the same directory the command is invoked
 - [x] just take care of the training for the decoder in a wrapper class, as each unet in the cascade will need its own optimizer
 - [x] bring in tools to train vqgan-vae
 - [x] add convnext backbone for vqgan-vae (in addition to vit [vit-vqgan] + resnet)
-- [ ] become an expert with unets, cleanup unet code, make it fully configurable, port all learnings over to https://github.com/lucidrains/x-unet
+- [x] make sure DDPMs can be run with traditional resnet blocks (but leave convnext as an option for experimentation)
+- [x] make sure for the latter unets in the cascade, one can train on crops for learning super resolution (constrain the unet to be only convolutions in that case, or allow conv-like attention with rel pos bias)
+- [ ] become an expert with unets, cleanup unet code, make it fully configurable, port all learnings over to https://github.com/lucidrains/x-unet (test out unet² in ddpm repo)
 - [ ] 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
 - [ ] pull logic for training diffusion prior into a class DiffusionPriorTrainer, for eventual script based + CLI based training
@@ -831,6 +833,10 @@ Once built, images will be saved to the same directory the command is invoked
 - [ ] bring in cross-scale embedding from iclr paper https://github.com/lucidrains/vit-pytorch/blob/main/vit_pytorch/crossformer.py#L14
 - [ ] figure out if possible to augment with external memory, as described in https://arxiv.org/abs/2204.11824
 - [ ] test out grid attention in cascading ddpm locally, decide whether to keep or remove
+- [ ] use an experimental tracker agnostic setup, as done <a href="https://github.com/lucidrains/tf-bind-transformer#simple-trainer-class-for-fine-tuning">here</a>
+- [ ] interface out the vqgan-vae so a pretrained one can be pulled off the shelf to validate latent diffusion + DALL-E2
+- [ ] make sure FILIP works with DALL-E2 from x-clip https://arxiv.org/abs/2111.07783
+- [ ] make sure resnet | convnext block hyperparameters can be configurable across unet depth (groups and expansion factor)
 
 ## Citations
 
@@ -896,4 +902,14 @@ Once built, images will be saved to the same directory the command is invoked
 }
 ```
 
-*Creating noise from data is easy; creating data from noise is generative modeling.* - Yang Song's <a href="https://arxiv.org/abs/2011.13456">paper</a>
+```bibtex
+@article{Shleifer2021NormFormerIT,
+    title   = {NormFormer: Improved Transformer Pretraining with Extra Normalization},
+    author  = {Sam Shleifer and Jason Weston and Myle Ott},
+    journal = {ArXiv},
+    year    = {2021},
+    volume  = {abs/2110.09456}
+}
+```
+
+*Creating noise from data is easy; creating data from noise is generative modeling.* - <a href="https://arxiv.org/abs/2011.13456">Yang Song's paper</a>

dalle2_pytorch/cli.py

@@ -1,6 +1,7 @@
 import click
 import torch
 import torchvision.transforms as T
+from functools import reduce
 from pathlib import Path
 
 from dalle2_pytorch import DALLE2, Decoder, DiffusionPrior

dalle2_pytorch/dalle2_pytorch.py

@@ -16,6 +16,7 @@ from einops_exts import rearrange_many, repeat_many, check_shape
 from einops_exts.torch import EinopsToAndFrom
 
 from kornia.filters import gaussian_blur2d
+import kornia.augmentation as K
 
 from dalle2_pytorch.tokenizer import tokenizer
 from dalle2_pytorch.vqgan_vae import NullVQGanVAE, VQGanVAE
@@ -29,6 +30,9 @@ from x_clip import CLIP
 def exists(val):
     return val is not None
 
+def identity(t, *args, **kwargs):
+    return t
+
 def default(val, d):
     if exists(val):
         return val
@@ -496,7 +500,12 @@ class SwiGLU(nn.Module):
         x, gate = x.chunk(2, dim = -1)
         return x * F.silu(gate)
 
-def FeedForward(dim, mult = 4, dropout = 0., post_activation_norm = False):
+def FeedForward(
+    dim,
+    mult = 4,
+    dropout = 0.,
+    post_activation_norm = False
+):
     """ post-activation norm https://arxiv.org/abs/2110.09456 """
 
     inner_dim = int(mult * dim)
@@ -519,7 +528,8 @@ class Attention(nn.Module):
         dim_head = 64,
         heads = 8,
         dropout = 0.,
-        causal = False
+        causal = False,
+        post_norm = False
     ):
         super().__init__()
         self.scale = dim_head ** -0.5
@@ -534,7 +544,11 @@ class Attention(nn.Module):
         self.null_kv = nn.Parameter(torch.randn(2, dim_head))
         self.to_q = nn.Linear(dim, inner_dim, bias = False)
         self.to_kv = nn.Linear(dim, dim_head * 2, bias = False)
-        self.to_out = nn.Linear(inner_dim, dim, bias = False)
+
+        self.to_out = nn.Sequential(
+            nn.Linear(inner_dim, dim, bias = False),
+            LayerNorm(dim) if post_norm else nn.Identity()
+        )
 
     def forward(self, x, mask = None, attn_bias = None):
         b, n, device = *x.shape[:2], x.device
@@ -596,10 +610,11 @@ class CausalTransformer(nn.Module):
         dim_head = 64,
         heads = 8,
         ff_mult = 4,
-        norm_out = False,
+        norm_out = True,
         attn_dropout = 0.,
         ff_dropout = 0.,
-        final_proj = True
+        final_proj = True,
+        normformer = False
     ):
         super().__init__()
         self.rel_pos_bias = RelPosBias(heads = heads)
@@ -607,8 +622,8 @@ class CausalTransformer(nn.Module):
         self.layers = nn.ModuleList([])
         for _ in range(depth):
             self.layers.append(nn.ModuleList([
-                Attention(dim = dim, causal = True, dim_head = dim_head, heads = heads, dropout = attn_dropout),
+                Attention(dim = dim, causal = True, dim_head = dim_head, heads = heads, dropout = attn_dropout, post_norm = normformer),
-                FeedForward(dim = dim, mult = ff_mult, dropout = ff_dropout)
+                FeedForward(dim = dim, mult = ff_mult, dropout = ff_dropout, post_activation_norm = normformer)
             ]))
 
         self.norm = LayerNorm(dim) if norm_out else nn.Identity()  # unclear in paper whether they projected after the classic layer norm for the final denoised image embedding, or just had the transformer output it directly: plan on offering both options
@@ -635,12 +650,14 @@ class DiffusionPriorNetwork(nn.Module):
         self,
         dim,
         num_timesteps = None,
+        l2norm_output = False,  # whether to restrict image embedding output with l2norm at the end (may make it easier to learn?)
         **kwargs
     ):
         super().__init__()
         self.time_embeddings = nn.Embedding(num_timesteps, dim) if exists(num_timesteps) else nn.Sequential(Rearrange('b -> b 1'), MLP(1, dim)) # also offer a continuous version of timestep embeddings, with a 2 layer MLP
         self.learned_query = nn.Parameter(torch.randn(dim))
         self.causal_transformer = CausalTransformer(dim = dim, **kwargs)
+        self.l2norm_output = l2norm_output
 
     def forward_with_cond_scale(
         self,
@@ -719,7 +736,8 @@ class DiffusionPriorNetwork(nn.Module):
 
         pred_image_embed = tokens[..., -1, :]
 
-        return pred_image_embed
+        output_fn = l2norm if self.l2norm_output else identity
+        return output_fn(pred_image_embed)
 
 class DiffusionPrior(BaseGaussianDiffusion):
     def __init__(
@@ -787,7 +805,7 @@ class DiffusionPrior(BaseGaussianDiffusion):
         model_mean, posterior_variance, posterior_log_variance = self.q_posterior(x_start=x_recon, x_t=x, t=t)
         return model_mean, posterior_variance, posterior_log_variance
 
-    @torch.no_grad()
+    @torch.inference_mode()
     def p_sample(self, x, t, text_cond = None, clip_denoised = True, repeat_noise = False):
         b, *_, device = *x.shape, x.device
         model_mean, _, model_log_variance = self.p_mean_variance(x = x, t = t, text_cond = text_cond, clip_denoised = clip_denoised)
@@ -796,7 +814,7 @@ class DiffusionPrior(BaseGaussianDiffusion):
         nonzero_mask = (1 - (t == 0).float()).reshape(b, *((1,) * (len(x.shape) - 1)))
         return model_mean + nonzero_mask * (0.5 * model_log_variance).exp() * noise
 
-    @torch.no_grad()
+    @torch.inference_mode()
     def p_sample_loop(self, shape, text_cond):
         device = self.betas.device
 
@@ -824,7 +842,7 @@ class DiffusionPrior(BaseGaussianDiffusion):
         loss = self.loss_fn(pred, target)
         return loss
 
-    @torch.no_grad()
+    @torch.inference_mode()
     @eval_decorator
     def sample(self, text, num_samples_per_batch = 2):
         # in the paper, what they did was
@@ -913,6 +931,72 @@ class SinusoidalPosEmb(nn.Module):
         emb = rearrange(x, 'i -> i 1') * rearrange(emb, 'j -> 1 j')
         return torch.cat((emb.sin(), emb.cos()), dim = -1)
 
+class Block(nn.Module):
+    def __init__(
+        self,
+        dim,
+        dim_out,
+        groups = 8
+    ):
+        super().__init__()
+        self.block = nn.Sequential(
+            nn.Conv2d(dim, dim_out, 3, padding = 1),
+            nn.GroupNorm(groups, dim_out),
+            nn.SiLU()
+        )
+    def forward(self, x):
+        return self.block(x)
+
+class ResnetBlock(nn.Module):
+    def __init__(
+        self,
+        dim,
+        dim_out,
+        *,
+        cond_dim = None,
+        time_cond_dim = None,
+        groups = 8
+    ):
+        super().__init__()
+
+        self.time_mlp = None
+
+        if exists(time_cond_dim):
+            self.time_mlp = nn.Sequential(
+                nn.SiLU(),
+                nn.Linear(time_cond_dim, dim_out)
+            )
+
+        self.cross_attn = None
+
+        if exists(cond_dim):
+            self.cross_attn = EinopsToAndFrom(
+                'b c h w',
+                'b (h w) c',
+                CrossAttention(
+                    dim = dim_out,
+                    context_dim = cond_dim
+                )
+            )
+
+        self.block1 = Block(dim, dim_out, groups = groups)
+        self.block2 = Block(dim_out, dim_out, groups = groups)
+        self.res_conv = nn.Conv2d(dim, dim_out, 1) if dim != dim_out else nn.Identity()
+
+    def forward(self, x, cond = None, time_emb = None):
+        h = self.block1(x)
+
+        if exists(self.time_mlp) and exists(time_emb):
+            time_emb = self.time_mlp(time_emb)
+            h = rearrange(time_emb, 'b c -> b c 1 1') + h
+
+        if exists(self.cross_attn):
+            assert exists(cond)
+            h = self.cross_attn(h, context = cond) + h
+
+        h = self.block2(h)
+        return h + self.res_conv(x)
+
 class ConvNextBlock(nn.Module):
     """ https://arxiv.org/abs/2201.03545 """
 
@@ -923,8 +1007,7 @@ class ConvNextBlock(nn.Module):
         *,
         cond_dim = None,
         time_cond_dim = None,
-        mult = 2,
+        mult = 2
-        norm = True
     ):
         super().__init__()
         need_projection = dim != dim_out
@@ -953,7 +1036,7 @@ class ConvNextBlock(nn.Module):
 
         inner_dim = int(dim_out * mult)
         self.net = nn.Sequential(
-            ChanLayerNorm(dim) if norm else nn.Identity(),
+            ChanLayerNorm(dim),
             nn.Conv2d(dim, inner_dim, 3, padding = 1),
             nn.GELU(),
             nn.Conv2d(inner_dim, dim_out, 3, padding = 1)
@@ -1065,7 +1148,11 @@ class LinearAttention(nn.Module):
 
         self.nonlin = nn.GELU()
         self.to_qkv = nn.Conv2d(dim, inner_dim * 3, 1, bias = False)
-        self.to_out = nn.Conv2d(inner_dim, dim, 1, bias = False)
+
+        self.to_out = nn.Sequential(
+            nn.Conv2d(inner_dim, dim, 1, bias = False),
+            ChanLayerNorm(dim)
+        )
 
     def forward(self, fmap):
         h, x, y = self.heads, *fmap.shape[-2:]
@@ -1108,7 +1195,11 @@ class Unet(nn.Module):
         max_text_len = 256,
         cond_on_image_embeds = False,
         init_dim = None,
-        init_conv_kernel_size = 7
+        init_conv_kernel_size = 7,
+        block_type = 'resnet',
+        block_resnet_groups = 8,
+        block_convnext_mult = 2,
+        **kwargs
     ):
         super().__init__()
         # save locals to take care of some hyperparameters for cascading DDPM
@@ -1183,6 +1274,15 @@ class Unet(nn.Module):
 
         attn_kwargs = dict(heads = attn_heads, dim_head = attn_dim_head)
 
+        # whether to use resnet or the (improved?) convnext blocks
+
+        if block_type == 'resnet':
+            block_klass = partial(ResnetBlock, groups = block_resnet_groups)
+        elif block_type == 'convnext':
+            block_klass = partial(ConvNextBlock, mult = block_convnext_mult)
+        else:
+            raise ValueError(f'unimplemented block type {block_type}')
+
         # layers
 
         self.downs = nn.ModuleList([])
@@ -1195,32 +1295,32 @@ class Unet(nn.Module):
             layer_cond_dim = cond_dim if not is_first else None
 
             self.downs.append(nn.ModuleList([
-                ConvNextBlock(dim_in, dim_out, time_cond_dim = time_cond_dim, norm = ind != 0),
+                block_klass(dim_in, dim_out, time_cond_dim = time_cond_dim),
                 Residual(LinearAttention(dim_out, **attn_kwargs)) if sparse_attn else nn.Identity(),
-                ConvNextBlock(dim_out, dim_out, cond_dim = layer_cond_dim, time_cond_dim = time_cond_dim),
+                block_klass(dim_out, dim_out, cond_dim = layer_cond_dim, time_cond_dim = time_cond_dim),
                 Downsample(dim_out) if not is_last else nn.Identity()
             ]))
 
         mid_dim = dims[-1]
 
-        self.mid_block1 = ConvNextBlock(mid_dim, mid_dim, cond_dim = cond_dim, time_cond_dim = time_cond_dim)
+        self.mid_block1 = block_klass(mid_dim, mid_dim, cond_dim = cond_dim, time_cond_dim = time_cond_dim)
         self.mid_attn = EinopsToAndFrom('b c h w', 'b (h w) c', Residual(Attention(mid_dim, **attn_kwargs))) if attend_at_middle else None
-        self.mid_block2 = ConvNextBlock(mid_dim, mid_dim, cond_dim = cond_dim, time_cond_dim = time_cond_dim)
+        self.mid_block2 = block_klass(mid_dim, mid_dim, cond_dim = cond_dim, time_cond_dim = time_cond_dim)
 
         for ind, (dim_in, dim_out) in enumerate(reversed(in_out[1:])):
             is_last = ind >= (num_resolutions - 2)
             layer_cond_dim = cond_dim if not is_last else None
 
             self.ups.append(nn.ModuleList([
-                ConvNextBlock(dim_out * 2, dim_in, cond_dim = layer_cond_dim, time_cond_dim = time_cond_dim),
+                block_klass(dim_out * 2, dim_in, cond_dim = layer_cond_dim, time_cond_dim = time_cond_dim),
                 Residual(LinearAttention(dim_in, **attn_kwargs)) if sparse_attn else nn.Identity(),
-                ConvNextBlock(dim_in, dim_in, cond_dim = layer_cond_dim, time_cond_dim = time_cond_dim),
+                block_klass(dim_in, dim_in, cond_dim = layer_cond_dim, time_cond_dim = time_cond_dim),
                 Upsample(dim_in)
             ]))
 
         out_dim = default(out_dim, channels)
         self.final_conv = nn.Sequential(
-            ConvNextBlock(dim, dim),
+            block_klass(dim, dim),
             nn.Conv2d(dim, out_dim, 1)
         )
 
@@ -1351,10 +1451,10 @@ class Unet(nn.Module):
 
         hiddens = []
 
-        for convnext, sparse_attn, convnext2, downsample in self.downs:
+        for block1, sparse_attn, block2, downsample in self.downs:
-            x = convnext(x, c, t)
+            x = block1(x, c, t)
             x = sparse_attn(x)
-            x = convnext2(x, c, t)
+            x = block2(x, c, t)
             hiddens.append(x)
             x = downsample(x)
 
@@ -1365,11 +1465,11 @@ class Unet(nn.Module):
 
         x = self.mid_block2(x, mid_c, t)
 
-        for convnext, sparse_attn, convnext2, upsample in self.ups:
+        for block1, sparse_attn, block2, upsample in self.ups:
             x = torch.cat((x, hiddens.pop()), dim=1)
-            x = convnext(x, c, t)
+            x = block1(x, c, t)
             x = sparse_attn(x)
-            x = convnext2(x, c, t)
+            x = block2(x, c, t)
             x = upsample(x)
 
         return self.final_conv(x)
@@ -1427,6 +1527,7 @@ class Decoder(BaseGaussianDiffusion):
         predict_x_start = False,
         predict_x_start_for_latent_diffusion = False,
         image_sizes = None,                         # for cascading ddpm, image size at each stage
+        random_crop_sizes = None,                   # whether to random crop the image at that stage in the cascade (super resoluting convolutions at the end may be able to generalize on smaller crops)
         lowres_cond_upsample_mode = 'bilinear',     # cascading ddpm - low resolution upsample mode
         lowres_downsample_first = True,             # cascading ddpm - resizes to lower resolution, then to next conditional resolution + blur
         blur_sigma = 0.1,                           # cascading ddpm - blur sigma
@@ -1489,6 +1590,10 @@ class Decoder(BaseGaussianDiffusion):
         self.image_sizes = image_sizes
         self.sample_channels = cast_tuple(self.channels, len(image_sizes))
 
+        # random crop sizes (for super-resoluting unets at the end of cascade?)
+
+        self.random_crop_sizes = cast_tuple(random_crop_sizes, len(image_sizes))
+
         # predict x0 config
 
         self.predict_x_start = cast_tuple(predict_x_start, len(unets)) if not predict_x_start_for_latent_diffusion else tuple(map(lambda t: isinstance(t, VQGanVAE), self.vaes))
@@ -1534,12 +1639,6 @@ class Decoder(BaseGaussianDiffusion):
         yield
         unet.cpu()
 
-
-    @torch.no_grad()
-    def get_image_embed(self, image):
-        image_embed, _ = self.clip.embed_image(image)
-        return image_embed
-
     def p_mean_variance(self, unet, x, t, image_embed, text_encodings = None, text_mask = None, lowres_cond_img = None, clip_denoised = True, predict_x_start = False, cond_scale = 1.):
         pred = unet.forward_with_cond_scale(x, t, image_embed = image_embed, text_encodings = text_encodings, text_mask = text_mask, cond_scale = cond_scale, lowres_cond_img = lowres_cond_img)
 
@@ -1554,7 +1653,7 @@ class Decoder(BaseGaussianDiffusion):
         model_mean, posterior_variance, posterior_log_variance = self.q_posterior(x_start=x_recon, x_t=x, t=t)
         return model_mean, posterior_variance, posterior_log_variance
 
-    @torch.no_grad()
+    @torch.inference_mode()
     def p_sample(self, unet, x, t, image_embed, text_encodings = None, text_mask = None, cond_scale = 1., lowres_cond_img = None, predict_x_start = False, clip_denoised = True, repeat_noise = False):
         b, *_, device = *x.shape, x.device
         model_mean, _, model_log_variance = self.p_mean_variance(unet, x = x, t = t, image_embed = image_embed, text_encodings = text_encodings, text_mask = text_mask, cond_scale = cond_scale, lowres_cond_img = lowres_cond_img, clip_denoised = clip_denoised, predict_x_start = predict_x_start)
@@ -1563,7 +1662,7 @@ class Decoder(BaseGaussianDiffusion):
         nonzero_mask = (1 - (t == 0).float()).reshape(b, *((1,) * (len(x.shape) - 1)))
         return model_mean + nonzero_mask * (0.5 * model_log_variance).exp() * noise
 
-    @torch.no_grad()
+    @torch.inference_mode()
     def p_sample_loop(self, unet, shape, image_embed, predict_x_start = False, clip_denoised = True, lowres_cond_img = None, text_encodings = None, text_mask = None, cond_scale = 1):
         device = self.betas.device
 
@@ -1607,7 +1706,7 @@ class Decoder(BaseGaussianDiffusion):
         loss = self.loss_fn(pred, target)
         return loss
 
-    @torch.no_grad()
+    @torch.inference_mode()
     @eval_decorator
     def sample(
         self,
@@ -1678,10 +1777,10 @@ class Decoder(BaseGaussianDiffusion):
 
         unet = self.get_unet(unet_number)
 
-        target_image_size = self.image_sizes[unet_index]
+        vae                 = self.vaes[unet_index]
-        vae = self.vaes[unet_index]
+        target_image_size   = self.image_sizes[unet_index]
-        predict_x_start = self.predict_x_start[unet_index]
+        predict_x_start     = self.predict_x_start[unet_index]
-
+        random_crop_size    = self.random_crop_sizes[unet_index]
         b, c, h, w, device, = *image.shape, image.device
 
         check_shape(image, 'b c h w', c = self.channels)
@@ -1702,6 +1801,14 @@ class Decoder(BaseGaussianDiffusion):
         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)
 
+        if exists(random_crop_size):
+            aug = K.RandomCrop((random_crop_size, random_crop_size), p = 1.)
+
+            # make sure low res conditioner and image both get augmented the same way
+            # detailed https://kornia.readthedocs.io/en/latest/augmentation.module.html?highlight=randomcrop#kornia.augmentation.RandomCrop
+            image = aug(image)
+            lowres_cond_img = aug(lowres_cond_img, params = aug._params)
+
         vae.eval()
         with torch.no_grad():
             image = vae.encode(image)
@@ -1732,7 +1839,7 @@ class DALLE2(nn.Module):
 
         self.to_pil = T.ToPILImage()
 
-    @torch.no_grad()
+    @torch.inference_mode()
     @eval_decorator
     def forward(
         self,

dalle2_pytorch/train.py

@@ -159,12 +159,13 @@ class DecoderTrainer(nn.Module):
         index = unet_number - 1
         unet = self.decoder.unets[index]
 
-        if exists(self.max_grad_norm):
-            nn.utils.clip_grad_norm_(unet.parameters(), self.max_grad_norm)
-
         optimizer = getattr(self, f'optim{index}')
         scaler = getattr(self, f'scaler{index}')
 
+        if exists(self.max_grad_norm):
+            scaler.unscale_(optimizer)
+            nn.utils.clip_grad_norm_(unet.parameters(), self.max_grad_norm)
+
         scaler.step(optimizer)
         scaler.update()
         optimizer.zero_grad()

setup.py

@@ -10,7 +10,7 @@ setup(
       'dream = dalle2_pytorch.cli:dream'
     ],
   },
-  version = '0.0.89',
+  version = '0.0.99',
   license='MIT',
   description = 'DALL-E 2',
   author = 'Phil Wang',

train_diffusion_prior.py

@@ -1,36 +1,78 @@
 import os
 import math
 import argparse
+import numpy as np
 
 import torch
 from torch import nn
 from embedding_reader import EmbeddingReader
 from dalle2_pytorch import DiffusionPrior, DiffusionPriorNetwork
 from dalle2_pytorch.optimizer import get_optimizer
+from torch.cuda.amp import autocast,GradScaler
 
 import time
 from tqdm import tqdm
 
 import wandb
 os.environ["WANDB_SILENT"] = "true"
+NUM_TEST_EMBEDDINGS = 100 # for cosine similarity reporting during training
+REPORT_METRICS_EVERY = 100 # for cosine similarity and other metric reporting during training
+
 
 def eval_model(model,device,image_reader,text_reader,start,end,batch_size,loss_type,phase="Validation"):
     model.eval()
     with torch.no_grad():
-        for emb_images,emb_text in zip(image_reader(batch_size=batch_size, start=start, end=end),
+        total_loss = 0.
+        total_samples = 0.
+
+        for emb_images, emb_text in zip(image_reader(batch_size=batch_size, start=start, end=end),
                 text_reader(batch_size=batch_size, start=start, end=end)):
+
             emb_images_tensor = torch.tensor(emb_images[0]).to(device)
             emb_text_tensor = torch.tensor(emb_text[0]).to(device)
+
+            batches = emb_images_tensor.shape[0]
+
             loss = model(text_embed = emb_text_tensor, image_embed = emb_images_tensor)
 
-            # Log to wandb
+            total_loss += loss.item() * batches
-            wandb.log({f'{phase} {loss_type}': loss})
+            total_samples += batches
 
-def save_model(save_path,state_dict):
+        avg_loss = (total_loss / total_samples)
+        wandb.log({f'{phase} {loss_type}': avg_loss})
+
+def save_model(save_path, state_dict):
     # Saving State Dict
     print("====================================== Saving checkpoint ======================================")
     torch.save(state_dict, save_path+'/'+str(time.time())+'_saved_model.pth')
 
+def report_cosine_sims(diffusion_prior,image_reader,text_reader,train_set_size,val_set_size,NUM_TEST_EMBEDDINGS,device):
+    cos = nn.CosineSimilarity(dim=1, eps=1e-6)
+
+    tstart = train_set_size+val_set_size
+    tend = train_set_size+val_set_size+NUM_TEST_EMBEDDINGS
+
+    for embt, embi in zip(text_reader(batch_size = NUM_TEST_EMBEDDINGS, start=tstart, end = tend),image_reader(batch_size = NUM_TEST_EMBEDDINGS, start=tstart, end = tend)):
+        text_embed = torch.tensor(embt[0]).to(device)
+        text_embed = text_embed /  text_embed.norm(dim=1, keepdim=True)
+        test_text_cond = dict(text_embed = text_embed)
+
+        test_image_embeddings = torch.tensor(embi[0]).to(device)
+        test_image_embeddings = test_image_embeddings /  test_image_embeddings.norm(dim=1, keepdim=True)
+
+        predicted_image_embeddings = diffusion_prior.p_sample_loop((NUM_TEST_EMBEDDINGS, 768), text_cond = test_text_cond)
+        predicted_image_embeddings = predicted_image_embeddings / predicted_image_embeddings.norm(dim=1, keepdim=True)
+
+        original_similarity = cos(text_embed,test_image_embeddings).cpu().numpy()
+        predicted_similarity = cos(text_embed,predicted_image_embeddings).cpu().numpy()
+
+        wandb.log({"CosineSimilarity(text_embed,image_embed)": np.mean(original_similarity)})
+        wandb.log({"CosineSimilarity(text_embed,predicted_image_embed)":np.mean(predicted_similarity)})
+
+    return np.mean(predicted_similarity - original_similarity)
+
+
+
 def train(image_embed_dim,
           image_embed_url,
           text_embed_url,
@@ -43,6 +85,8 @@ def train(image_embed_dim,
           clip,
           dp_condition_on_text_encodings,
           dp_timesteps,
+          dp_l2norm_output,
+          dp_normformer,
           dp_cond_drop_prob,
           dpn_depth,
           dpn_dim_head,
@@ -52,14 +96,17 @@ def train(image_embed_dim,
           device,
           learning_rate=0.001,
           max_grad_norm=0.5,
-          weight_decay=0.01):
+          weight_decay=0.01,
+          amp=False):
 
     # DiffusionPriorNetwork 
     prior_network = DiffusionPriorNetwork( 
             dim = image_embed_dim, 
             depth = dpn_depth, 
             dim_head = dpn_dim_head, 
-            heads = dpn_heads).to(device)
+            heads = dpn_heads,
+            normformer = dp_normformer,
+            l2norm_output = dp_l2norm_output).to(device)
     
     # DiffusionPrior with text embeddings and image embeddings pre-computed
     diffusion_prior = DiffusionPrior( 
@@ -82,6 +129,7 @@ def train(image_embed_dim,
         os.makedirs(save_path)
 
     ### Training code ###
+    scaler = GradScaler(enabled=amp)
     optimizer = get_optimizer(diffusion_prior.net.parameters(), wd=weight_decay, lr=learning_rate)
     epochs = num_epochs
 
@@ -98,23 +146,45 @@ def train(image_embed_dim,
                 text_reader(batch_size=batch_size, start=0, end=train_set_size)):
             emb_images_tensor = torch.tensor(emb_images[0]).to(device)
             emb_text_tensor = torch.tensor(emb_text[0]).to(device)
-            optimizer.zero_grad()
+
-            loss = diffusion_prior(text_embed = emb_text_tensor,image_embed = emb_images_tensor)
+            with autocast(enabled=amp):
-            loss.backward()
+                loss = diffusion_prior(text_embed = emb_text_tensor,image_embed = emb_images_tensor)
+                scaler.scale(loss).backward()
+
             # Samples per second
             step+=1
             samples_per_sec = batch_size*step/(time.time()-t)
             # Save checkpoint every save_interval minutes
             if(int(time.time()-t) >= 60*save_interval):
                 t = time.time()
-                save_model(save_path,diffusion_prior.state_dict())
+
+                save_model(
+                    save_path,
+                    dict(model=diffusion_prior.state_dict(), optimizer=optimizer.state_dict(), scaler=scaler.state_dict()))
+
             # Log to wandb
             wandb.log({"Training loss": loss.item(),
                         "Steps": step,
                         "Samples per second": samples_per_sec})
+            # Log cosineSim(text_embed,predicted_image_embed) - cosineSim(text_embed,image_embed)
+            # Use NUM_TEST_EMBEDDINGS samples from the test set each time
+            # Get embeddings from the most recently saved model
+            if(step % REPORT_METRICS_EVERY) == 0:
+                diff_cosine_sim = report_cosine_sims(diffusion_prior,
+                        image_reader,
+                        text_reader,
+                        train_set_size,
+                        val_set_size,
+                        NUM_TEST_EMBEDDINGS,
+                        device)
+                wandb.log({"Cosine similarity difference": diff_cosine_sim})
 
-            nn.init.clip_grad_norm_(diffusion_prior.parameters(), max_grad_norm)
+            scaler.unscale_(optimizer)
-            optimizer.step()
+            nn.utils.clip_grad_norm_(diffusion_prior.parameters(), max_grad_norm)
+
+            scaler.step(optimizer)
+            scaler.update()
+            optimizer.zero_grad()
 
         ### Evaluate model(validation run) ###
         start = train_set_size
@@ -139,8 +209,8 @@ def main():
     parser.add_argument("--image-embed-url", type=str, default="https://mystic.the-eye.eu/public/AI/cah/laion5b/embeddings/laion2B-en/img_emb/")
     parser.add_argument("--text-embed-url", type=str, default="https://mystic.the-eye.eu/public/AI/cah/laion5b/embeddings/laion2B-en/text_emb/")
     # Hyperparameters
-    parser.add_argument("--learning-rate", type=float, default=0.001)
+    parser.add_argument("--learning-rate", type=float, default=1.1e-4)
-    parser.add_argument("--weight-decay", type=float, default=0.01)
+    parser.add_argument("--weight-decay", type=float, default=6.02e-2)
     parser.add_argument("--max-grad-norm", type=float, default=0.5)
     parser.add_argument("--batch-size", type=int, default=10**4)
     parser.add_argument("--num-epochs", type=int, default=5)
@@ -158,15 +228,20 @@ def main():
     # DiffusionPrior(dp) parameters
     parser.add_argument("--dp-condition-on-text-encodings", type=bool, default=False)
     parser.add_argument("--dp-timesteps", type=int, default=100)
-    parser.add_argument("--dp-cond-drop-prob", type=float, default=0.2)
+    parser.add_argument("--dp-l2norm-output", type=bool, default=False)
+    parser.add_argument("--dp-normformer", type=bool, default=False)
+    parser.add_argument("--dp-cond-drop-prob", type=float, default=0.1)
     parser.add_argument("--dp-loss-type", type=str, default="l2")
     parser.add_argument("--clip", type=str, default=None)
+    parser.add_argument("--amp", type=bool, default=False)
     # Model checkpointing interval(minutes)
     parser.add_argument("--save-interval", type=int, default=30)
     parser.add_argument("--save-path", type=str, default="./diffusion_prior_checkpoints")
 
     args = parser.parse_args()
+
     print("Setting up wandb logging... Please wait...")
+
     wandb.init(
       entity=args.wandb_entity,
       project=args.wandb_project,
@@ -176,6 +251,7 @@ def main():
       "dataset": args.wandb_dataset,
       "epochs": args.num_epochs,
       })
+
     print("wandb logging setup done!")
     # Obtain the utilized device.
 
@@ -197,6 +273,8 @@ def main():
           args.clip,
           args.dp_condition_on_text_encodings,
           args.dp_timesteps,
+          args.dp_l2norm_output,
+          args.dp_normformer,
           args.dp_cond_drop_prob,
           args.dpn_depth,
           args.dpn_dim_head,
@@ -206,7 +284,8 @@ def main():
           device,
           args.learning_rate,
           args.max_grad_norm,
-          args.weight_decay)
+          args.weight_decay,
+          args.amp)
 
 if __name__ == "__main__":
   main()