implement token warmup

library/train_util.py

@@ -277,6 +277,8 @@ class BaseSubset:
         caption_dropout_rate: float,
         caption_dropout_every_n_epochs: int,
         caption_tag_dropout_rate: float,
+        token_warmup_min: int,
+        token_warmup_step: Union[float,int],
     ) -> None:
         self.image_dir = image_dir
         self.num_repeats = num_repeats
@@ -290,6 +292,9 @@ class BaseSubset:
         self.caption_dropout_every_n_epochs = caption_dropout_every_n_epochs
         self.caption_tag_dropout_rate = caption_tag_dropout_rate
 
+        self.token_warmup_min = token_warmup_min  # step=0におけるタグの数
+        self.token_warmup_step = token_warmup_step  # N（N<1ならN*max_train_steps）ステップ目でタグの数が最大になる
+
         self.img_count = 0
 
 
@@ -310,6 +315,8 @@ class DreamBoothSubset(BaseSubset):
         caption_dropout_rate,
         caption_dropout_every_n_epochs,
         caption_tag_dropout_rate,
+        token_warmup_min,
+        token_warmup_step,
     ) -> None:
         assert image_dir is not None, "image_dir must be specified / image_dirは指定が必須です"
 
@@ -325,6 +332,8 @@ class DreamBoothSubset(BaseSubset):
             caption_dropout_rate,
             caption_dropout_every_n_epochs,
             caption_tag_dropout_rate,
+            token_warmup_min,
+            token_warmup_step,
         )
 
         self.is_reg = is_reg
@@ -352,6 +361,8 @@ class FineTuningSubset(BaseSubset):
         caption_dropout_rate,
         caption_dropout_every_n_epochs,
         caption_tag_dropout_rate,
+        token_warmup_min,
+        token_warmup_step,
     ) -> None:
         assert metadata_file is not None, "metadata_file must be specified / metadata_fileは指定が必須です"
 
@@ -367,6 +378,8 @@ class FineTuningSubset(BaseSubset):
             caption_dropout_rate,
             caption_dropout_every_n_epochs,
             caption_tag_dropout_rate,
+            token_warmup_min,
+            token_warmup_step,
         )
 
         self.metadata_file = metadata_file
@@ -405,6 +418,9 @@ class BaseDataset(torch.utils.data.Dataset):
 
         self.current_epoch: int = 0  # インスタンスがepochごとに新しく作られるようなので外側から渡さないとダメ
 
+        self.current_step: int = 0
+        self.max_train_steps: int = 0
+
         # augmentation
         self.aug_helper = AugHelper()
 
@@ -424,6 +440,12 @@ class BaseDataset(torch.utils.data.Dataset):
         self.current_epoch = epoch
         self.shuffle_buckets()
 
+    def set_current_step(self, step):
+        self.current_step = step
+
+    def set_max_train_steps(self, max_train_steps):
+        self.max_train_steps = max_train_steps
+
     def set_tag_frequency(self, dir_name, captions):
         frequency_for_dir = self.tag_frequency.get(dir_name, {})
         self.tag_frequency[dir_name] = frequency_for_dir
@@ -453,7 +475,7 @@ class BaseDataset(torch.utils.data.Dataset):
         if is_drop_out:
             caption = ""
         else:
-            if subset.shuffle_caption or subset.caption_tag_dropout_rate > 0:
+            if subset.shuffle_caption or subset.token_warmup_step > 0 or subset.caption_tag_dropout_rate > 0:
 
                 def dropout_tags(tokens):
                     if subset.caption_tag_dropout_rate <= 0:
@@ -474,8 +496,15 @@ class BaseDataset(torch.utils.data.Dataset):
                     random.shuffle(flex_tokens)
 
                 flex_tokens = dropout_tags(flex_tokens)
+                tokens = fixed_tokens + flex_tokens
 
-                caption = ", ".join(fixed_tokens + flex_tokens)
+                if subset.token_warmup_step < 1:
+                    subset.token_warmup_step = math.floor(subset.token_warmup_step * self.max_train_steps)
+                if subset.token_warmup_step and self.current_step < subset.token_warmup_step:
+                    tokens_len = math.floor((self.current_step)*((len(tokens)-subset.token_warmup_min)/(subset.token_warmup_step)))+subset.token_warmup_min
+                    tokens = tokens[:tokens_len]
+
+                caption = ", ".join(tokens)
 
             # textual inversion対応
             for str_from, str_to in self.replacements.items():
@@ -1249,6 +1278,14 @@ class DatasetGroup(torch.utils.data.ConcatDataset):
         for dataset in self.datasets:
             dataset.set_current_epoch(epoch)
 
+    def set_current_step(self, step):
+        for dataset in self.datasets:
+            dataset.set_current_step(step)
+
+    def set_max_train_steps(self, max_train_steps):
+        for dataset in self.datasets:
+            dataset.set_max_train_steps(max_train_steps)
+
     def disable_token_padding(self):
         for dataset in self.datasets:
             dataset.disable_token_padding()
@@ -2001,6 +2038,20 @@ def add_dataset_arguments(
         "--bucket_no_upscale", action="store_true", help="make bucket for each image without upscaling / 画像を拡大せずbucketを作成します"
     )
 
+    parser.add_argument(
+        "--token_warmup_min",
+        type=int,
+        default=1,
+        help="start learning at N tags (token means comma separated strinfloatgs) / タグ数をN個から増やしながら学習する",
+    )
+
+    parser.add_argument(
+        "--token_warmup_steps",
+        type=float,
+        default=0,
+        help="tag length reaches maximum on N steps (or N*max_train_steps if N<1) / N（N<1ならN*max_train_steps）ステップでタグ長が最大になる。デフォルトは0（最初から最大）",
+    )
+    
     if support_caption_dropout:
         # Textual Inversion はcaptionのdropoutをsupportしない
         # いわゆるtensorのDropoutと紛らわしいのでprefixにcaptionを付けておく　every_n_epochsは他と平仄を合わせてdefault Noneに