feat: SUPIR model support (CORE-17) (#13250)

comfy/ldm/modules/diffusionmodules/openaimodel.py

@@ -34,6 +34,16 @@ class TimestepBlock(nn.Module):
 #This is needed because accelerate makes a copy of transformer_options which breaks "transformer_index"
 def forward_timestep_embed(ts, x, emb, context=None, transformer_options={}, output_shape=None, time_context=None, num_video_frames=None, image_only_indicator=None):
     for layer in ts:
+        if "patches" in transformer_options and "forward_timestep_embed_patch" in transformer_options["patches"]:
+            found_patched = False
+            for class_type, handler in transformer_options["patches"]["forward_timestep_embed_patch"]:
+                if isinstance(layer, class_type):
+                    x = handler(layer, x, emb, context, transformer_options, output_shape, time_context, num_video_frames, image_only_indicator)
+                    found_patched = True
+                    break
+            if found_patched:
+                continue
+
         if isinstance(layer, VideoResBlock):
             x = layer(x, emb, num_video_frames, image_only_indicator)
         elif isinstance(layer, TimestepBlock):
@@ -49,15 +59,6 @@ def forward_timestep_embed(ts, x, emb, context=None, transformer_options={}, out
         elif isinstance(layer, Upsample):
             x = layer(x, output_shape=output_shape)
         else:
-            if "patches" in transformer_options and "forward_timestep_embed_patch" in transformer_options["patches"]:
-                found_patched = False
-                for class_type, handler in transformer_options["patches"]["forward_timestep_embed_patch"]:
-                    if isinstance(layer, class_type):
-                        x = handler(layer, x, emb, context, transformer_options, output_shape, time_context, num_video_frames, image_only_indicator)
-                        found_patched = True
-                        break
-                if found_patched:
-                    continue
             x = layer(x)
     return x
 
@@ -894,6 +895,12 @@ class UNetModel(nn.Module):
             h = forward_timestep_embed(self.middle_block, h, emb, context, transformer_options, time_context=time_context, num_video_frames=num_video_frames, image_only_indicator=image_only_indicator)
         h = apply_control(h, control, 'middle')
 
+        if "middle_block_after_patch" in transformer_patches:
+            patch = transformer_patches["middle_block_after_patch"]
+            for p in patch:
+                out = p({"h": h, "x": x, "emb": emb, "context": context, "y": y,
+                         "timesteps": timesteps, "transformer_options": transformer_options})
+                h = out["h"]
 
         for id, module in enumerate(self.output_blocks):
             transformer_options["block"] = ("output", id)
@@ -905,8 +912,9 @@ class UNetModel(nn.Module):
                 for p in patch:
                     h, hsp = p(h, hsp, transformer_options)
 
-            h = th.cat([h, hsp], dim=1)
-            del hsp
+            if hsp is not None:
+                h = th.cat([h, hsp], dim=1)
+                del hsp
             if len(hs) > 0:
                 output_shape = hs[-1].shape
             else:

comfy/ldm/supir/supir_modules.py

@@ -0,0 +1,226 @@
+import torch
+import torch.nn as nn
+
+from comfy.ldm.modules.diffusionmodules.util import timestep_embedding
+from comfy.ldm.modules.diffusionmodules.openaimodel import Downsample, TimestepEmbedSequential, ResBlock, SpatialTransformer
+from comfy.ldm.modules.attention import optimized_attention
+
+
+class ZeroSFT(nn.Module):
+    def __init__(self, label_nc, norm_nc, concat_channels=0, dtype=None, device=None, operations=None):
+        super().__init__()
+
+        ks = 3
+        pw = ks // 2
+
+        self.param_free_norm = operations.GroupNorm(32, norm_nc + concat_channels, dtype=dtype, device=device)
+
+        nhidden = 128
+
+        self.mlp_shared = nn.Sequential(
+            operations.Conv2d(label_nc, nhidden, kernel_size=ks, padding=pw, dtype=dtype, device=device),
+            nn.SiLU()
+        )
+        self.zero_mul = operations.Conv2d(nhidden, norm_nc + concat_channels, kernel_size=ks, padding=pw, dtype=dtype, device=device)
+        self.zero_add = operations.Conv2d(nhidden, norm_nc + concat_channels, kernel_size=ks, padding=pw, dtype=dtype, device=device)
+
+        self.zero_conv = operations.Conv2d(label_nc, norm_nc, 1, 1, 0, dtype=dtype, device=device)
+        self.pre_concat = bool(concat_channels != 0)
+
+    def forward(self, c, h, h_ori=None, control_scale=1):
+        if h_ori is not None and self.pre_concat:
+            h_raw = torch.cat([h_ori, h], dim=1)
+        else:
+            h_raw = h
+
+        h = h + self.zero_conv(c)
+        if h_ori is not None and self.pre_concat:
+            h = torch.cat([h_ori, h], dim=1)
+        actv = self.mlp_shared(c)
+        gamma = self.zero_mul(actv)
+        beta = self.zero_add(actv)
+        h = self.param_free_norm(h)
+        h = torch.addcmul(h + beta, h, gamma)
+        if h_ori is not None and not self.pre_concat:
+            h = torch.cat([h_ori, h], dim=1)
+        return torch.lerp(h_raw, h, control_scale)
+
+
+class _CrossAttnInner(nn.Module):
+    """Inner cross-attention module matching the state_dict layout of the original CrossAttention."""
+    def __init__(self, query_dim, context_dim, heads, dim_head, dtype=None, device=None, operations=None):
+        super().__init__()
+        inner_dim = dim_head * heads
+        self.heads = heads
+        self.to_q = operations.Linear(query_dim, inner_dim, bias=False, dtype=dtype, device=device)
+        self.to_k = operations.Linear(context_dim, inner_dim, bias=False, dtype=dtype, device=device)
+        self.to_v = operations.Linear(context_dim, inner_dim, bias=False, dtype=dtype, device=device)
+        self.to_out = nn.Sequential(
+            operations.Linear(inner_dim, query_dim, dtype=dtype, device=device),
+        )
+
+    def forward(self, x, context):
+        q = self.to_q(x)
+        k = self.to_k(context)
+        v = self.to_v(context)
+        return self.to_out(optimized_attention(q, k, v, self.heads))
+
+
+class ZeroCrossAttn(nn.Module):
+    def __init__(self, context_dim, query_dim, dtype=None, device=None, operations=None):
+        super().__init__()
+        heads = query_dim // 64
+        dim_head = 64
+        self.attn = _CrossAttnInner(query_dim, context_dim, heads, dim_head, dtype=dtype, device=device, operations=operations)
+        self.norm1 = operations.GroupNorm(32, query_dim, dtype=dtype, device=device)
+        self.norm2 = operations.GroupNorm(32, context_dim, dtype=dtype, device=device)
+
+    def forward(self, context, x, control_scale=1):
+        b, c, h, w = x.shape
+        x_in = x
+
+        x = self.attn(
+            self.norm1(x).flatten(2).transpose(1, 2),
+            self.norm2(context).flatten(2).transpose(1, 2),
+        ).transpose(1, 2).unflatten(2, (h, w))
+
+        return x_in + x * control_scale
+
+
+class GLVControl(nn.Module):
+    """SUPIR's Guided Latent Vector control encoder. Truncated UNet (input + middle blocks only)."""
+    def __init__(
+        self,
+        in_channels=4,
+        model_channels=320,
+        num_res_blocks=2,
+        attention_resolutions=(4, 2),
+        channel_mult=(1, 2, 4),
+        num_head_channels=64,
+        transformer_depth=(1, 2, 10),
+        context_dim=2048,
+        adm_in_channels=2816,
+        use_linear_in_transformer=True,
+        use_checkpoint=False,
+        dtype=None,
+        device=None,
+        operations=None,
+        **kwargs,
+    ):
+        super().__init__()
+        self.model_channels = model_channels
+        time_embed_dim = model_channels * 4
+
+        self.time_embed = nn.Sequential(
+            operations.Linear(model_channels, time_embed_dim, dtype=dtype, device=device),
+            nn.SiLU(),
+            operations.Linear(time_embed_dim, time_embed_dim, dtype=dtype, device=device),
+        )
+
+        self.label_emb = nn.Sequential(
+            nn.Sequential(
+                operations.Linear(adm_in_channels, time_embed_dim, dtype=dtype, device=device),
+                nn.SiLU(),
+                operations.Linear(time_embed_dim, time_embed_dim, dtype=dtype, device=device),
+            )
+        )
+
+        self.input_blocks = nn.ModuleList([
+            TimestepEmbedSequential(
+                operations.Conv2d(in_channels, model_channels, 3, padding=1, dtype=dtype, device=device)
+            )
+        ])
+        ch = model_channels
+        ds = 1
+        for level, mult in enumerate(channel_mult):
+            for nr in range(num_res_blocks):
+                layers = [
+                    ResBlock(ch, time_embed_dim, 0, out_channels=mult * model_channels,
+                             dtype=dtype, device=device, operations=operations)
+                ]
+                ch = mult * model_channels
+                if ds in attention_resolutions:
+                    num_heads = ch // num_head_channels
+                    layers.append(
+                        SpatialTransformer(ch, num_heads, num_head_channels,
+                                           depth=transformer_depth[level], context_dim=context_dim,
+                                           use_linear=use_linear_in_transformer,
+                                           use_checkpoint=use_checkpoint,
+                                           dtype=dtype, device=device, operations=operations)
+                    )
+                self.input_blocks.append(TimestepEmbedSequential(*layers))
+            if level != len(channel_mult) - 1:
+                self.input_blocks.append(
+                    TimestepEmbedSequential(
+                        Downsample(ch, True, out_channels=ch, dtype=dtype, device=device, operations=operations)
+                    )
+                )
+                ds *= 2
+
+        num_heads = ch // num_head_channels
+        self.middle_block = TimestepEmbedSequential(
+            ResBlock(ch, time_embed_dim, 0, dtype=dtype, device=device, operations=operations),
+            SpatialTransformer(ch, num_heads, num_head_channels,
+                               depth=transformer_depth[-1], context_dim=context_dim,
+                               use_linear=use_linear_in_transformer,
+                               use_checkpoint=use_checkpoint,
+                               dtype=dtype, device=device, operations=operations),
+            ResBlock(ch, time_embed_dim, 0, dtype=dtype, device=device, operations=operations),
+        )
+
+        self.input_hint_block = TimestepEmbedSequential(
+            operations.Conv2d(in_channels, model_channels, 3, padding=1, dtype=dtype, device=device)
+        )
+
+    def forward(self, x, timesteps, xt, context=None, y=None, **kwargs):
+        t_emb = timestep_embedding(timesteps, self.model_channels, repeat_only=False).to(x.dtype)
+        emb = self.time_embed(t_emb) + self.label_emb(y)
+
+        guided_hint = self.input_hint_block(x, emb, context)
+
+        hs = []
+        h = xt
+        for module in self.input_blocks:
+            if guided_hint is not None:
+                h = module(h, emb, context)
+                h += guided_hint
+                guided_hint = None
+            else:
+                h = module(h, emb, context)
+            hs.append(h)
+        h = self.middle_block(h, emb, context)
+        hs.append(h)
+        return hs
+
+
+class SUPIR(nn.Module):
+    """
+    SUPIR model containing GLVControl (control encoder) and project_modules (adapters).
+    State dict keys match the original SUPIR checkpoint layout:
+      control_model.*           -> GLVControl
+      project_modules.*         -> nn.ModuleList of ZeroSFT/ZeroCrossAttn
+    """
+    def __init__(self, device=None, dtype=None, operations=None):
+        super().__init__()
+
+        self.control_model = GLVControl(dtype=dtype, device=device, operations=operations)
+
+        project_channel_scale = 2
+        cond_output_channels = [320] * 4 + [640] * 3 + [1280] * 3
+        project_channels = [int(c * project_channel_scale) for c in [160] * 4 + [320] * 3 + [640] * 3]
+        concat_channels = [320] * 2 + [640] * 3 + [1280] * 4 + [0]
+        cross_attn_insert_idx = [6, 3]
+
+        self.project_modules = nn.ModuleList()
+        for i in range(len(cond_output_channels)):
+            self.project_modules.append(ZeroSFT(
+                project_channels[i], cond_output_channels[i],
+                concat_channels=concat_channels[i],
+                dtype=dtype, device=device, operations=operations,
+            ))
+
+        for i in cross_attn_insert_idx:
+            self.project_modules.insert(i, ZeroCrossAttn(
+                cond_output_channels[i], concat_channels[i],
+                dtype=dtype, device=device, operations=operations,
+            ))

comfy/ldm/supir/supir_patch.py

@@ -0,0 +1,103 @@
+import torch
+from comfy.ldm.modules.diffusionmodules.openaimodel import Upsample
+
+
+class SUPIRPatch:
+    """
+    Holds GLVControl (control encoder) + project_modules (ZeroSFT/ZeroCrossAttn adapters).
+    Runs GLVControl lazily on first patch invocation per step, applies adapters through
+    middle_block_after_patch, output_block_merge_patch, and forward_timestep_embed_patch.
+    """
+    SIGMA_MAX = 14.6146
+
+    def __init__(self, model_patch, project_modules, hint_latent, strength_start, strength_end):
+        self.model_patch = model_patch           # CoreModelPatcher wrapping GLVControl
+        self.project_modules = project_modules   # nn.ModuleList of ZeroSFT/ZeroCrossAttn
+        self.hint_latent = hint_latent           # encoded LQ image latent
+        self.strength_start = strength_start
+        self.strength_end = strength_end
+        self.cached_features = None
+        self.adapter_idx = 0
+        self.control_idx = 0
+        self.current_control_idx = 0
+        self.active = True
+
+    def _ensure_features(self, kwargs):
+        """Run GLVControl on first call per step, cache results."""
+        if self.cached_features is not None:
+            return
+        x = kwargs["x"]
+        b = x.shape[0]
+        hint = self.hint_latent.to(device=x.device, dtype=x.dtype)
+        if hint.shape[0] != b:
+            hint = hint.expand(b, -1, -1, -1) if hint.shape[0] == 1 else hint.repeat((b + hint.shape[0] - 1) // hint.shape[0], 1, 1, 1)[:b]
+        self.cached_features = self.model_patch.model.control_model(
+            hint, kwargs["timesteps"], x,
+            kwargs["context"], kwargs["y"]
+        )
+        self.adapter_idx = len(self.project_modules) - 1
+        self.control_idx = len(self.cached_features) - 1
+
+    def _get_control_scale(self, kwargs):
+        if self.strength_start == self.strength_end:
+            return self.strength_end
+        sigma = kwargs["transformer_options"].get("sigmas")
+        if sigma is None:
+            return self.strength_end
+        s = sigma[0].item() if sigma.dim() > 0 else sigma.item()
+        t = min(s / self.SIGMA_MAX, 1.0)
+        return t * (self.strength_start - self.strength_end) + self.strength_end
+
+    def middle_after(self, kwargs):
+        """middle_block_after_patch: run GLVControl lazily, apply last adapter after middle block."""
+        self.cached_features = None  # reset from previous step
+        self.current_scale = self._get_control_scale(kwargs)
+        self.active = self.current_scale > 0
+        if not self.active:
+            return {"h": kwargs["h"]}
+        self._ensure_features(kwargs)
+        h = kwargs["h"]
+        h = self.project_modules[self.adapter_idx](
+            self.cached_features[self.control_idx], h, control_scale=self.current_scale
+        )
+        self.adapter_idx -= 1
+        self.control_idx -= 1
+        return {"h": h}
+
+    def output_block(self, h, hsp, transformer_options):
+        """output_block_patch: ZeroSFT adapter fusion replaces cat([h, hsp]). Returns (h, None) to skip cat."""
+        if not self.active:
+            return h, hsp
+        self.current_control_idx = self.control_idx
+        h = self.project_modules[self.adapter_idx](
+            self.cached_features[self.control_idx], hsp, h, control_scale=self.current_scale
+        )
+        self.adapter_idx -= 1
+        self.control_idx -= 1
+        return h, None
+
+    def pre_upsample(self, layer, x, emb, context, transformer_options, output_shape, *args, **kw):
+        """forward_timestep_embed_patch for Upsample: extra cross-attn adapter before upsample."""
+        block_type, _ = transformer_options["block"]
+        if block_type == "output" and self.active and self.cached_features is not None:
+            x = self.project_modules[self.adapter_idx](
+                self.cached_features[self.current_control_idx], x, control_scale=self.current_scale
+            )
+            self.adapter_idx -= 1
+        return layer(x, output_shape=output_shape)
+
+    def to(self, device_or_dtype):
+        if isinstance(device_or_dtype, torch.device):
+            self.cached_features = None
+            if self.hint_latent is not None:
+                self.hint_latent = self.hint_latent.to(device_or_dtype)
+        return self
+
+    def models(self):
+        return [self.model_patch]
+
+    def register(self, model_patcher):
+        """Register all patches on a cloned model patcher."""
+        model_patcher.set_model_patch(self.middle_after, "middle_block_after_patch")
+        model_patcher.set_model_output_block_patch(self.output_block)
+        model_patcher.set_model_patch((Upsample, self.pre_upsample), "forward_timestep_embed_patch")

comfy/model_patcher.py

@@ -506,6 +506,10 @@ class ModelPatcher:
     def set_model_noise_refiner_patch(self, patch):
         self.set_model_patch(patch, "noise_refiner")
 
+    def set_model_middle_block_after_patch(self, patch):
+        self.set_model_patch(patch, "middle_block_after_patch")
+
+
     def set_model_rope_options(self, scale_x, shift_x, scale_y, shift_y, scale_t, shift_t, **kwargs):
         rope_options = self.model_options["transformer_options"].get("rope_options", {})
         rope_options["scale_x"] = scale_x

comfy_extras/nodes_model_patch.py

@@ -7,7 +7,10 @@ import comfy.model_management
 import comfy.ldm.common_dit
 import comfy.latent_formats
 import comfy.ldm.lumina.controlnet
+import comfy.ldm.supir.supir_modules
 from comfy.ldm.wan.model_multitalk import WanMultiTalkAttentionBlock, MultiTalkAudioProjModel
+from comfy_api.latest import io
+from comfy.ldm.supir.supir_patch import SUPIRPatch
 
 
 class BlockWiseControlBlock(torch.nn.Module):
@@ -266,6 +269,27 @@ class ModelPatchLoader:
                     out_dim=sd["audio_proj.norm.weight"].shape[0],
                     device=comfy.model_management.unet_offload_device(),
                     operations=comfy.ops.manual_cast)
+        elif 'model.control_model.input_hint_block.0.weight' in sd or 'control_model.input_hint_block.0.weight' in sd:
+            prefix_replace = {}
+            if 'model.control_model.input_hint_block.0.weight' in sd:
+                prefix_replace["model.control_model."] = "control_model."
+                prefix_replace["model.diffusion_model.project_modules."] = "project_modules."
+            else:
+                prefix_replace["control_model."] = "control_model."
+                prefix_replace["project_modules."] = "project_modules."
+
+            # Extract denoise_encoder weights before filter_keys discards them
+            de_prefix = "first_stage_model.denoise_encoder."
+            denoise_encoder_sd = {}
+            for k in list(sd.keys()):
+                if k.startswith(de_prefix):
+                    denoise_encoder_sd[k[len(de_prefix):]] = sd.pop(k)
+
+            sd = comfy.utils.state_dict_prefix_replace(sd, prefix_replace, filter_keys=True)
+            sd.pop("control_model.mask_LQ", None)
+            model = comfy.ldm.supir.supir_modules.SUPIR(device=comfy.model_management.unet_offload_device(), dtype=dtype, operations=comfy.ops.manual_cast)
+            if denoise_encoder_sd:
+                model.denoise_encoder_sd = denoise_encoder_sd
 
         model_patcher = comfy.model_patcher.CoreModelPatcher(model, load_device=comfy.model_management.get_torch_device(), offload_device=comfy.model_management.unet_offload_device())
         model.load_state_dict(sd, assign=model_patcher.is_dynamic())
@@ -565,9 +589,89 @@ class MultiTalkModelPatch(torch.nn.Module):
         )
 
 
+class SUPIRApply(io.ComfyNode):
+    @classmethod
+    def define_schema(cls) -> io.Schema:
+        return io.Schema(
+            node_id="SUPIRApply",
+            category="model_patches/supir",
+            is_experimental=True,
+            inputs=[
+                io.Model.Input("model"),
+                io.ModelPatch.Input("model_patch"),
+                io.Vae.Input("vae"),
+                io.Image.Input("image"),
+                io.Float.Input("strength_start", default=1.0, min=0.0, max=10.0, step=0.01,
+                               tooltip="Control strength at the start of sampling (high sigma)."),
+                io.Float.Input("strength_end", default=1.0, min=0.0, max=10.0, step=0.01,
+                               tooltip="Control strength at the end of sampling (low sigma). Linearly interpolated from start."),
+                io.Float.Input("restore_cfg", default=4.0, min=0.0, max=20.0, step=0.1, advanced=True,
+                               tooltip="Pulls denoised output toward the input latent. Higher = stronger fidelity to input. 0 to disable."),
+                io.Float.Input("restore_cfg_s_tmin", default=0.05, min=0.0, max=1.0, step=0.01, advanced=True,
+                               tooltip="Sigma threshold below which restore_cfg is disabled."),
+            ],
+            outputs=[io.Model.Output()],
+        )
+
+    @classmethod
+    def _encode_with_denoise_encoder(cls, vae, model_patch, image):
+        """Encode using denoise_encoder weights from SUPIR checkpoint if available."""
+        denoise_sd = getattr(model_patch.model, 'denoise_encoder_sd', None)
+        if not denoise_sd:
+            return vae.encode(image)
+
+        # Clone VAE patcher, apply denoise_encoder weights to clone, encode
+        orig_patcher = vae.patcher
+        vae.patcher = orig_patcher.clone()
+        patches = {f"encoder.{k}": (v,) for k, v in denoise_sd.items()}
+        vae.patcher.add_patches(patches, strength_patch=1.0, strength_model=0.0)
+        try:
+            return vae.encode(image)
+        finally:
+            vae.patcher = orig_patcher
+
+    @classmethod
+    def execute(cls, *, model: io.Model.Type, model_patch: io.ModelPatch.Type, vae: io.Vae.Type, image: io.Image.Type,
+                strength_start: float, strength_end: float, restore_cfg: float, restore_cfg_s_tmin: float) -> io.NodeOutput:
+        model_patched = model.clone()
+        hint_latent = model.get_model_object("latent_format").process_in(
+            cls._encode_with_denoise_encoder(vae, model_patch, image[:, :, :, :3]))
+        patch = SUPIRPatch(model_patch, model_patch.model.project_modules, hint_latent, strength_start, strength_end)
+        patch.register(model_patched)
+
+        if restore_cfg > 0.0:
+            # Round-trip to match original pipeline: decode hint, re-encode with regular VAE
+            latent_format = model.get_model_object("latent_format")
+            decoded = vae.decode(latent_format.process_out(hint_latent))
+            x_center = latent_format.process_in(vae.encode(decoded[:, :, :, :3]))
+            sigma_max = 14.6146
+
+            def restore_cfg_function(args):
+                denoised = args["denoised"]
+                sigma = args["sigma"]
+                if sigma.dim() > 0:
+                    s = sigma[0].item()
+                else:
+                    s = sigma.item()
+                if s > restore_cfg_s_tmin:
+                    ref = x_center.to(device=denoised.device, dtype=denoised.dtype)
+                    b = denoised.shape[0]
+                    if ref.shape[0] != b:
+                        ref = ref.expand(b, -1, -1, -1) if ref.shape[0] == 1 else ref.repeat((b + ref.shape[0] - 1) // ref.shape[0], 1, 1, 1)[:b]
+                    sigma_val = sigma.view(-1, 1, 1, 1) if sigma.dim() > 0 else sigma
+                    d_center = denoised - ref
+                    denoised = denoised - d_center * ((sigma_val / sigma_max) ** restore_cfg)
+                return denoised
+
+            model_patched.set_model_sampler_post_cfg_function(restore_cfg_function)
+
+        return io.NodeOutput(model_patched)
+
+
 NODE_CLASS_MAPPINGS = {
     "ModelPatchLoader": ModelPatchLoader,
     "QwenImageDiffsynthControlnet": QwenImageDiffsynthControlnet,
     "ZImageFunControlnet": ZImageFunControlnet,
     "USOStyleReference": USOStyleReference,
+    "SUPIRApply": SUPIRApply,
 }

comfy_extras/nodes_post_processing.py

@@ -6,6 +6,7 @@ from PIL import Image
 import math
 from enum import Enum
 from typing import TypedDict, Literal
+import kornia
 
 import comfy.utils
 import comfy.model_management
@@ -660,6 +661,228 @@ class BatchImagesMasksLatentsNode(io.ComfyNode):
         return io.NodeOutput(batched)
 
 
+class ColorTransfer(io.ComfyNode):
+    @classmethod
+    def define_schema(cls):
+        return io.Schema(
+            node_id="ColorTransfer",
+            category="image/postprocessing",
+            description="Match the colors of one image to another using various algorithms.",
+            search_aliases=["color match", "color grading", "color correction", "match colors", "color transform", "mkl", "reinhard", "histogram"],
+            inputs=[
+                io.Image.Input("image_target", tooltip="Image(s) to apply the color transform to."),
+                io.Image.Input("image_ref", optional=True, tooltip="Reference image(s) to match colors to. If not provided, processing is skipped"),
+                io.Combo.Input("method", options=['reinhard_lab', 'mkl_lab', 'histogram'],),
+                io.DynamicCombo.Input("source_stats",
+                    tooltip="per_frame: each frame matched to image_ref individually. uniform: pool stats across all source frames as baseline, match to image_ref. target_frame: use one chosen frame as the baseline for the transform to image_ref, applied uniformly to all frames (preserves relative differences)",
+                    options=[
+                        io.DynamicCombo.Option("per_frame", []),
+                        io.DynamicCombo.Option("uniform", []),
+                        io.DynamicCombo.Option("target_frame", [
+                            io.Int.Input("target_index", default=0, min=0, max=10000,
+                                tooltip="Frame index used as the source baseline for computing the transform to image_ref"),
+                        ]),
+                    ]),
+                io.Float.Input("strength", default=1.0, min=0.0, max=10.0, step=0.01),
+            ],
+            outputs=[
+                io.Image.Output(display_name="image"),
+            ],
+        )
+
+    @staticmethod
+    def _to_lab(images, i, device):
+        return kornia.color.rgb_to_lab(
+            images[i:i+1].to(device, dtype=torch.float32).permute(0, 3, 1, 2))
+
+    @staticmethod
+    def _pool_stats(images, device, is_reinhard, eps):
+        """Two-pass pooled mean + std/cov across all frames."""
+        N, C = images.shape[0], images.shape[3]
+        HW = images.shape[1] * images.shape[2]
+        mean = torch.zeros(C, 1, device=device, dtype=torch.float32)
+        for i in range(N):
+            mean += ColorTransfer._to_lab(images, i, device).view(C, -1).mean(dim=-1, keepdim=True)
+        mean /= N
+        acc = torch.zeros(C, 1 if is_reinhard else C, device=device, dtype=torch.float32)
+        for i in range(N):
+            centered = ColorTransfer._to_lab(images, i, device).view(C, -1) - mean
+            if is_reinhard:
+                acc += (centered * centered).mean(dim=-1, keepdim=True)
+            else:
+                acc += centered @ centered.T / HW
+        if is_reinhard:
+            return mean, torch.sqrt(acc / N).clamp_min_(eps)
+        return mean, acc / N
+
+    @staticmethod
+    def _frame_stats(lab_flat, hw, is_reinhard, eps):
+        """Per-frame mean + std/cov."""
+        mean = lab_flat.mean(dim=-1, keepdim=True)
+        if is_reinhard:
+            return mean, lab_flat.std(dim=-1, keepdim=True, unbiased=False).clamp_min_(eps)
+        centered = lab_flat - mean
+        return mean, centered @ centered.T / hw
+
+    @staticmethod
+    def _mkl_matrix(cov_s, cov_r, eps):
+        """Compute MKL 3x3 transform matrix from source and ref covariances."""
+        eig_val_s, eig_vec_s = torch.linalg.eigh(cov_s)
+        sqrt_val_s = torch.sqrt(eig_val_s.clamp_min(0)).clamp_min_(eps)
+
+        scaled_V = eig_vec_s * sqrt_val_s.unsqueeze(0)
+        mid = scaled_V.T @ cov_r @ scaled_V
+        eig_val_m, eig_vec_m = torch.linalg.eigh(mid)
+        sqrt_m = torch.sqrt(eig_val_m.clamp_min(0))
+
+        inv_sqrt_s = 1.0 / sqrt_val_s
+        inv_scaled_V = eig_vec_s * inv_sqrt_s.unsqueeze(0)
+        M_half = (eig_vec_m * sqrt_m.unsqueeze(0)) @ eig_vec_m.T
+        return inv_scaled_V @ M_half @ inv_scaled_V.T
+
+    @staticmethod
+    def _histogram_lut(src, ref, bins=256):
+        """Build per-channel LUT from source and ref histograms. src/ref: (C, HW) in [0,1]."""
+        s_bins = (src * (bins - 1)).long().clamp(0, bins - 1)
+        r_bins = (ref * (bins - 1)).long().clamp(0, bins - 1)
+        s_hist = torch.zeros(src.shape[0], bins, device=src.device, dtype=src.dtype)
+        r_hist = torch.zeros(src.shape[0], bins, device=src.device, dtype=src.dtype)
+        ones_s = torch.ones_like(src)
+        ones_r = torch.ones_like(ref)
+        s_hist.scatter_add_(1, s_bins, ones_s)
+        r_hist.scatter_add_(1, r_bins, ones_r)
+        s_cdf = s_hist.cumsum(1)
+        s_cdf = s_cdf / s_cdf[:, -1:]
+        r_cdf = r_hist.cumsum(1)
+        r_cdf = r_cdf / r_cdf[:, -1:]
+        return torch.searchsorted(r_cdf, s_cdf).clamp_max_(bins - 1).float() / (bins - 1)
+
+    @classmethod
+    def _pooled_cdf(cls, images, device, num_bins=256):
+        """Build pooled CDF across all frames, one frame at a time."""
+        C = images.shape[3]
+        hist = torch.zeros(C, num_bins, device=device, dtype=torch.float32)
+        for i in range(images.shape[0]):
+            frame = images[i].to(device, dtype=torch.float32).permute(2, 0, 1).reshape(C, -1)
+            bins = (frame * (num_bins - 1)).long().clamp(0, num_bins - 1)
+            hist.scatter_add_(1, bins, torch.ones_like(frame))
+        cdf = hist.cumsum(1)
+        return cdf / cdf[:, -1:]
+
+    @classmethod
+    def _build_histogram_transform(cls, image_target, image_ref, device, stats_mode, target_index, B):
+        """Build per-frame or uniform LUT transform for histogram mode."""
+        if stats_mode == 'per_frame':
+            return None  # LUT computed per-frame in the apply loop
+
+        r_cdf = cls._pooled_cdf(image_ref, device)
+        if stats_mode == 'target_frame':
+            ti = min(target_index, B - 1)
+            s_cdf = cls._pooled_cdf(image_target[ti:ti+1], device)
+        else:
+            s_cdf = cls._pooled_cdf(image_target, device)
+        return torch.searchsorted(r_cdf, s_cdf).clamp_max_(255).float() / 255.0
+
+    @classmethod
+    def _build_lab_transform(cls, image_target, image_ref, device, stats_mode, target_index, is_reinhard):
+        """Build transform parameters for Lab-based methods. Returns a transform function."""
+        eps = 1e-6
+        B, H, W, C = image_target.shape
+        B_ref = image_ref.shape[0]
+        single_ref = B_ref == 1
+        HW = H * W
+        HW_ref = image_ref.shape[1] * image_ref.shape[2]
+
+        # Precompute ref stats
+        if single_ref or stats_mode in ('uniform', 'target_frame'):
+            ref_mean, ref_sc = cls._pool_stats(image_ref, device, is_reinhard, eps)
+
+        # Uniform/target_frame: precompute single affine transform
+        if stats_mode in ('uniform', 'target_frame'):
+            if stats_mode == 'target_frame':
+                ti = min(target_index, B - 1)
+                s_lab = cls._to_lab(image_target, ti, device).view(C, -1)
+                s_mean, s_sc = cls._frame_stats(s_lab, HW, is_reinhard, eps)
+            else:
+                s_mean, s_sc = cls._pool_stats(image_target, device, is_reinhard, eps)
+
+            if is_reinhard:
+                scale = ref_sc / s_sc
+                offset = ref_mean - scale * s_mean
+                return lambda src_flat, **_: src_flat * scale + offset
+            T = cls._mkl_matrix(s_sc, ref_sc, eps)
+            offset = ref_mean - T @ s_mean
+            return lambda src_flat, **_: T @ src_flat + offset
+
+        # per_frame
+        def per_frame_transform(src_flat, frame_idx):
+            s_mean, s_sc = cls._frame_stats(src_flat, HW, is_reinhard, eps)
+
+            if single_ref:
+                r_mean, r_sc = ref_mean, ref_sc
+            else:
+                ri = min(frame_idx, B_ref - 1)
+                r_mean, r_sc = cls._frame_stats(cls._to_lab(image_ref, ri, device).view(C, -1), HW_ref, is_reinhard, eps)
+
+            centered = src_flat - s_mean
+            if is_reinhard:
+                return centered * (r_sc / s_sc) + r_mean
+            T = cls._mkl_matrix(centered @ centered.T / HW, r_sc, eps)
+            return T @ centered + r_mean
+
+        return per_frame_transform
+
+    @classmethod
+    def execute(cls, image_target, image_ref, method, source_stats, strength=1.0) -> io.NodeOutput:
+        stats_mode = source_stats["source_stats"]
+        target_index = source_stats.get("target_index", 0)
+
+        if strength == 0 or image_ref is None:
+            return io.NodeOutput(image_target)
+
+        device = comfy.model_management.get_torch_device()
+        intermediate_device = comfy.model_management.intermediate_device()
+        intermediate_dtype = comfy.model_management.intermediate_dtype()
+
+        B, H, W, C = image_target.shape
+        B_ref = image_ref.shape[0]
+        pbar = comfy.utils.ProgressBar(B)
+        out = torch.empty(B, H, W, C, device=intermediate_device, dtype=intermediate_dtype)
+
+        if method == 'histogram':
+            uniform_lut = cls._build_histogram_transform(
+                image_target, image_ref, device, stats_mode, target_index, B)
+
+            for i in range(B):
+                src = image_target[i].to(device, dtype=torch.float32).permute(2, 0, 1)
+                src_flat = src.reshape(C, -1)
+                if uniform_lut is not None:
+                    lut = uniform_lut
+                else:
+                    ri = min(i, B_ref - 1)
+                    ref = image_ref[ri].to(device, dtype=torch.float32).permute(2, 0, 1).reshape(C, -1)
+                    lut = cls._histogram_lut(src_flat, ref)
+                bin_idx = (src_flat * 255).long().clamp(0, 255)
+                matched = lut.gather(1, bin_idx).view(C, H, W)
+                result = matched if strength == 1.0 else torch.lerp(src, matched, strength)
+                out[i] = result.permute(1, 2, 0).clamp_(0, 1).to(device=intermediate_device, dtype=intermediate_dtype)
+                pbar.update(1)
+        else:
+            transform = cls._build_lab_transform(image_target, image_ref, device, stats_mode, target_index, is_reinhard=method == "reinhard_lab")
+
+            for i in range(B):
+                src_frame = cls._to_lab(image_target, i, device)
+                corrected = transform(src_frame.view(C, -1), frame_idx=i)
+                if strength == 1.0:
+                    result = kornia.color.lab_to_rgb(corrected.view(1, C, H, W))
+                else:
+                    result = kornia.color.lab_to_rgb(torch.lerp(src_frame, corrected.view(1, C, H, W), strength))
+                out[i] = result.squeeze(0).permute(1, 2, 0).clamp_(0, 1).to(device=intermediate_device, dtype=intermediate_dtype)
+                pbar.update(1)
+
+        return io.NodeOutput(out)
+
+
 class PostProcessingExtension(ComfyExtension):
     @override
     async def get_node_list(self) -> list[type[io.ComfyNode]]:
@@ -673,6 +896,7 @@ class PostProcessingExtension(ComfyExtension):
             BatchImagesNode,
             BatchMasksNode,
             BatchLatentsNode,
+            ColorTransfer,
             # BatchImagesMasksLatentsNode,
         ]