remove convnext blocks, they are illsuited for generative work, validated by early experimental results at https://github.com/lucidrains/video-diffusion-pytorch

README.md

@@ -866,14 +866,6 @@ Once built, images will be saved to the same directory the command is invoked
 }
 ```
 
-```bibtex
-@inproceedings{Liu2022ACF,
-    title   = {A ConvNet for the 2020s},
-    author  = {Zhuang Liu and Hanzi Mao and Chaozheng Wu and Christoph Feichtenhofer and Trevor Darrell and Saining Xie},
-    year    = {2022}
-}
-```
-
 ```bibtex
 @article{shen2019efficient,
     author  = {Zhuoran Shen and Mingyuan Zhang and Haiyu Zhao and Shuai Yi and Hongsheng Li},

dalle2_pytorch/dalle2_pytorch.py

@@ -21,6 +21,8 @@ import kornia.augmentation as K
 from dalle2_pytorch.tokenizer import tokenizer
 from dalle2_pytorch.vqgan_vae import NullVQGanVAE, VQGanVAE
 
+from resize_right import resize
+
 # use x-clip
 
 from x_clip import CLIP
@@ -86,14 +88,14 @@ def freeze_model_and_make_eval_(model):
 def l2norm(t):
     return F.normalize(t, dim = -1)
 
-def resize_image_to(t, image_size, mode = 'bilinear'): # take a look at https://github.com/assafshocher/ResizeRight
-    shape = cast_tuple(image_size, 2)
-    orig_image_size = t.shape[-2:]
+def resize_image_to(image, target_image_size):
+    orig_image_size = image.shape[-1]
 
-    if orig_image_size == shape:
-        return t
+    if orig_image_size == target_image_size:
+        return image
 
-    return F.interpolate(t, size = shape, mode = mode, align_corners = False)
+    scale_factors = target_image_size / orig_image_size
+    return resize(image, scale_factors = scale_factors)
 
 # image normalization functions
 # ddpms expect images to be in the range of -1 to 1
@@ -997,68 +999,6 @@ class ResnetBlock(nn.Module):
         h = self.block2(h)
         return h + self.res_conv(x)
 
-class ConvNextBlock(nn.Module):
-    """ https://arxiv.org/abs/2201.03545 """
-
-    def __init__(
-        self,
-        dim,
-        dim_out,
-        *,
-        cond_dim = None,
-        time_cond_dim = None,
-        mult = 2
-    ):
-        super().__init__()
-        need_projection = 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,
-                    context_dim = cond_dim
-                )
-            )
-
-        self.time_mlp = None
-
-        if exists(time_cond_dim):
-            self.time_mlp = nn.Sequential(
-                nn.GELU(),
-                nn.Linear(time_cond_dim, dim)
-            )
-
-        self.ds_conv = nn.Conv2d(dim, dim, 7, padding = 3, groups = dim)
-
-        inner_dim = int(dim_out * mult)
-        self.net = nn.Sequential(
-            ChanLayerNorm(dim),
-            nn.Conv2d(dim, inner_dim, 3, padding = 1),
-            nn.GELU(),
-            nn.Conv2d(inner_dim, dim_out, 3, padding = 1)
-        )
-
-        self.res_conv = nn.Conv2d(dim, dim_out, 1) if need_projection else nn.Identity()
-
-    def forward(self, x, cond = None, time = None):
-        h = self.ds_conv(x)
-
-        if exists(time) and exists(self.time_mlp):
-            t = self.time_mlp(time)
-            h = rearrange(t, '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.net(h)
-
-        return h + self.res_conv(x)
-
 class CrossAttention(nn.Module):
     def __init__(
         self,
@@ -1198,7 +1138,6 @@ class Unet(nn.Module):
         init_conv_kernel_size = 7,
         block_type = 'resnet',
         block_resnet_groups = 8,
-        block_convnext_mult = 2,
         **kwargs
     ):
         super().__init__()
@@ -1274,14 +1213,9 @@ class Unet(nn.Module):
 
         attn_kwargs = dict(heads = attn_heads, dim_head = attn_dim_head)
 
-        # whether to use resnet or the (improved?) convnext blocks
+        # resnet block klass
 
-        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}')
+        block_klass = partial(ResnetBlock, groups = block_resnet_groups)
 
         # layers
 
@@ -1477,13 +1411,11 @@ class Unet(nn.Module):
 class LowresConditioner(nn.Module):
     def __init__(
         self,
-        cond_upsample_mode = 'bilinear',
         downsample_first = True,
         blur_sigma = 0.1,
         blur_kernel_size = 3,
     ):
         super().__init__()
-        self.cond_upsample_mode = cond_upsample_mode
         self.downsample_first = downsample_first
         self.blur_sigma = blur_sigma
         self.blur_kernel_size = blur_kernel_size
@@ -1497,10 +1429,8 @@ class LowresConditioner(nn.Module):
         blur_sigma = None,
         blur_kernel_size = None
     ):
-        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, downsample_image_size, mode = self.cond_upsample_mode)
+            cond_fmap = resize_image_to(cond_fmap, downsample_image_size)
 
         if self.training:
             # when training, blur the low resolution conditional image
@@ -1508,7 +1438,7 @@ class LowresConditioner(nn.Module):
             blur_kernel_size = default(blur_kernel_size, self.blur_kernel_size)
             cond_fmap = gaussian_blur2d(cond_fmap, cast_tuple(blur_kernel_size, 2), cast_tuple(blur_sigma, 2))
 
-        cond_fmap = resize_image_to(cond_fmap, target_image_size, mode = self.cond_upsample_mode)
+        cond_fmap = resize_image_to(cond_fmap, target_image_size)
 
         return cond_fmap
 
@@ -1528,7 +1458,6 @@ class Decoder(BaseGaussianDiffusion):
         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
         blur_kernel_size = 3,                       # cascading ddpm - blur kernel size
@@ -1604,7 +1533,6 @@ class Decoder(BaseGaussianDiffusion):
         assert lowres_conditions == (False, *((True,) * (len(self.unets) - 1))), 'the first unet must be unconditioned (by low resolution image), and the rest of the unets must have `lowres_cond` set to True'
 
         self.to_lowres_cond = LowresConditioner(
-            cond_upsample_mode = lowres_cond_upsample_mode,
             downsample_first = lowres_downsample_first,
             blur_sigma = blur_sigma,
             blur_kernel_size = blur_kernel_size,

dalle2_pytorch/vqgan_vae.py

@@ -331,112 +331,6 @@ class ResBlock(nn.Module):
     def forward(self, x):
         return self.net(x) + x
 
-# convnext enc dec
-
-class ChanLayerNorm(nn.Module):
-    def __init__(self, dim, eps = 1e-5):
-        super().__init__()
-        self.eps = eps
-        self.g = nn.Parameter(torch.ones(1, dim, 1, 1))
-
-    def forward(self, x):
-        var = torch.var(x, dim = 1, unbiased = False, keepdim = True)
-        mean = torch.mean(x, dim = 1, keepdim = True)
-        return (x - mean) / (var + self.eps).sqrt() * self.g
-
-class ConvNext(nn.Module):
-    def __init__(self, dim, mult = 4, kernel_size = 3, ds_kernel_size = 7):
-        super().__init__()
-        inner_dim = int(dim * mult)
-        self.net = nn.Sequential(
-            nn.Conv2d(dim, dim, ds_kernel_size, padding = ds_kernel_size // 2, groups = dim),
-            ChanLayerNorm(dim),
-            nn.Conv2d(dim, inner_dim, kernel_size, padding = kernel_size // 2),
-            nn.GELU(),
-            nn.Conv2d(inner_dim, dim, kernel_size, padding = kernel_size // 2)
-        )
-
-    def forward(self, x):
-        return self.net(x) + x
-
-class ConvNextEncDec(nn.Module):
-    def __init__(
-        self,
-        dim,
-        *,
-        channels = 3,
-        layers = 4,
-        layer_mults = None,
-        num_blocks = 1,
-        first_conv_kernel_size = 5,
-        use_attn = True,
-        attn_dim_head = 64,
-        attn_heads = 8,
-        attn_dropout = 0.,
-    ):
-        super().__init__()
-
-        self.layers = layers
-
-        self.encoders = MList([])
-        self.decoders = MList([])
-
-        layer_mults = default(layer_mults, list(map(lambda t: 2 ** t, range(layers))))
-        assert len(layer_mults) == layers, 'layer multipliers must be equal to designated number of layers'
-
-        layer_dims = [dim * mult for mult in layer_mults]
-        dims = (dim, *layer_dims)
-
-        self.encoded_dim = dims[-1]
-
-        dim_pairs = zip(dims[:-1], dims[1:])
-
-        append = lambda arr, t: arr.append(t)
-        prepend = lambda arr, t: arr.insert(0, t)
-
-        if not isinstance(num_blocks, tuple):
-            num_blocks = (*((0,) * (layers - 1)), num_blocks)
-
-        if not isinstance(use_attn, tuple):
-            use_attn = (*((False,) * (layers - 1)), use_attn)
-
-        assert len(num_blocks) == layers, 'number of blocks config must be equal to number of layers'
-        assert len(use_attn) == layers
-
-        for layer_index, (dim_in, dim_out), layer_num_blocks, layer_use_attn in zip(range(layers), dim_pairs, num_blocks, use_attn):
-            append(self.encoders, nn.Sequential(nn.Conv2d(dim_in, dim_out, 4, stride = 2, padding = 1), leaky_relu()))
-            prepend(self.decoders, nn.Sequential(nn.ConvTranspose2d(dim_out, dim_in, 4, 2, 1), leaky_relu()))
-
-            if layer_use_attn:
-                prepend(self.decoders, VQGanAttention(dim = dim_out, heads = attn_heads, dim_head = attn_dim_head, dropout = attn_dropout))
-
-            for _ in range(layer_num_blocks):
-                append(self.encoders, ConvNext(dim_out))
-                prepend(self.decoders, ConvNext(dim_out))
-
-            if layer_use_attn:
-                append(self.encoders, VQGanAttention(dim = dim_out, heads = attn_heads, dim_head = attn_dim_head, dropout = attn_dropout))
-
-        prepend(self.encoders, nn.Conv2d(channels, dim, first_conv_kernel_size, padding = first_conv_kernel_size // 2))
-        append(self.decoders, nn.Conv2d(dim, channels, 1))
-
-    def get_encoded_fmap_size(self, image_size):
-        return image_size // (2 ** self.layers)
-
-    @property
-    def last_dec_layer(self):
-        return self.decoders[-1].weight
-
-    def encode(self, x):
-        for enc in self.encoders:
-            x = enc(x)
-        return x
-
-    def decode(self, x):
-        for dec in self.decoders:
-            x = dec(x)
-        return x
-
 # vqgan attention layer
 
 class VQGanAttention(nn.Module):
@@ -682,8 +576,6 @@ class VQGanVAE(nn.Module):
             enc_dec_klass = ResnetEncDec
         elif vae_type == 'vit':
             enc_dec_klass = ViTEncDec
-        elif vae_type == 'convnext':
-            enc_dec_klass = ConvNextEncDec
         else:
             raise ValueError(f'{vae_type} not valid')
 

setup.py

@@ -10,7 +10,7 @@ setup(
       'dream = dalle2_pytorch.cli:dream'
     ],
   },
-  version = '0.0.99',
+  version = '0.0.101',
   license='MIT',
   description = 'DALL-E 2',
   author = 'Phil Wang',
@@ -29,6 +29,7 @@ setup(
     'embedding-reader',
     'kornia>=0.5.4',
     'pillow',
+    'resize-right>=0.0.2',
     'torch>=1.10',
     'torchvision',
     'tqdm',