Add support for unCLIP SD2.x models.

See _for_testing/unclip in the UI for the new nodes.

unCLIPCheckpointLoader is used to load them.

unCLIPConditioning is used to add the image cond and takes as input a
CLIPVisionEncode output which has been moved to the conditioning section.

comfy/ldm/models/diffusion/ddpm.py

@@ -1801,3 +1801,75 @@ class LatentUpscaleFinetuneDiffusion(LatentFinetuneDiffusion):
         log = super().log_images(*args, **kwargs)
         log["lr"] = rearrange(args[0]["lr"], 'b h w c -> b c h w')
         return log
+
+
+class ImageEmbeddingConditionedLatentDiffusion(LatentDiffusion):
+    def __init__(self, embedder_config=None, embedding_key="jpg", embedding_dropout=0.5,
+                 freeze_embedder=True, noise_aug_config=None, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.embed_key = embedding_key
+        self.embedding_dropout = embedding_dropout
+        # self._init_embedder(embedder_config, freeze_embedder)
+        self._init_noise_aug(noise_aug_config)
+
+    def _init_embedder(self, config, freeze=True):
+        embedder = instantiate_from_config(config)
+        if freeze:
+            self.embedder = embedder.eval()
+            self.embedder.train = disabled_train
+            for param in self.embedder.parameters():
+                param.requires_grad = False
+
+    def _init_noise_aug(self, config):
+        if config is not None:
+            # use the KARLO schedule for noise augmentation on CLIP image embeddings
+            noise_augmentor = instantiate_from_config(config)
+            assert isinstance(noise_augmentor, nn.Module)
+            noise_augmentor = noise_augmentor.eval()
+            noise_augmentor.train = disabled_train
+            self.noise_augmentor = noise_augmentor
+        else:
+            self.noise_augmentor = None
+
+    def get_input(self, batch, k, cond_key=None, bs=None, **kwargs):
+        outputs = LatentDiffusion.get_input(self, batch, k, bs=bs, **kwargs)
+        z, c = outputs[0], outputs[1]
+        img = batch[self.embed_key][:bs]
+        img = rearrange(img, 'b h w c -> b c h w')
+        c_adm = self.embedder(img)
+        if self.noise_augmentor is not None:
+            c_adm, noise_level_emb = self.noise_augmentor(c_adm)
+            # assume this gives embeddings of noise levels
+            c_adm = torch.cat((c_adm, noise_level_emb), 1)
+        if self.training:
+            c_adm = torch.bernoulli((1. - self.embedding_dropout) * torch.ones(c_adm.shape[0],
+                                                                               device=c_adm.device)[:, None]) * c_adm
+        all_conds = {"c_crossattn": [c], "c_adm": c_adm}
+        noutputs = [z, all_conds]
+        noutputs.extend(outputs[2:])
+        return noutputs
+
+    @torch.no_grad()
+    def log_images(self, batch, N=8, n_row=4, **kwargs):
+        log = dict()
+        z, c, x, xrec, xc = self.get_input(batch, self.first_stage_key, bs=N, return_first_stage_outputs=True,
+                                           return_original_cond=True)
+        log["inputs"] = x
+        log["reconstruction"] = xrec
+        assert self.model.conditioning_key is not None
+        assert self.cond_stage_key in ["caption", "txt"]
+        xc = log_txt_as_img((x.shape[2], x.shape[3]), batch[self.cond_stage_key], size=x.shape[2] // 25)
+        log["conditioning"] = xc
+        uc = self.get_unconditional_conditioning(N, kwargs.get('unconditional_guidance_label', ''))
+        unconditional_guidance_scale = kwargs.get('unconditional_guidance_scale', 5.)
+
+        uc_ = {"c_crossattn": [uc], "c_adm": c["c_adm"]}
+        ema_scope = self.ema_scope if kwargs.get('use_ema_scope', True) else nullcontext
+        with ema_scope(f"Sampling"):
+            samples_cfg, _ = self.sample_log(cond=c, batch_size=N, ddim=True,
+                                             ddim_steps=kwargs.get('ddim_steps', 50), eta=kwargs.get('ddim_eta', 0.),
+                                             unconditional_guidance_scale=unconditional_guidance_scale,
+                                             unconditional_conditioning=uc_, )
+            x_samples_cfg = self.decode_first_stage(samples_cfg)
+            log[f"samplescfg_scale_{unconditional_guidance_scale:.2f}"] = x_samples_cfg
+        return log