Add some latent operation nodes.

This is a port of the ModelSamplerTonemapNoiseTest from the experiments
repo.

To replicate that node use LatentOperationTonemapReinhard and
LatentApplyOperationCFG together.

comfy_extras/nodes_latent.py

@@ -145,6 +145,82 @@ class LatentBatchSeedBehavior:
 
         return (samples_out,)
 
+class LatentApplyOperation:
+    @classmethod
+    def INPUT_TYPES(s):
+        return {"required": { "samples": ("LATENT",),
+                             "operation": ("LATENT_OPERATION",),
+                             }}
+
+    RETURN_TYPES = ("LATENT",)
+    FUNCTION = "op"
+
+    CATEGORY = "latent/advanced/operations"
+    EXPERIMENTAL = True
+
+    def op(self, samples, operation):
+        samples_out = samples.copy()
+
+        s1 = samples["samples"]
+        samples_out["samples"] = operation(latent=s1)
+        return (samples_out,)
+
+class LatentApplyOperationCFG:
+    @classmethod
+    def INPUT_TYPES(s):
+        return {"required": { "model": ("MODEL",),
+                             "operation": ("LATENT_OPERATION",),
+                              }}
+    RETURN_TYPES = ("MODEL",)
+    FUNCTION = "patch"
+
+    CATEGORY = "latent/advanced/operations"
+    EXPERIMENTAL = True
+
+    def patch(self, model, operation):
+        m = model.clone()
+
+        def pre_cfg_function(args):
+            conds_out = args["conds_out"]
+            if len(conds_out) == 2:
+                conds_out[0] = operation(latent=(conds_out[0] - conds_out[1])) + conds_out[1]
+            else:
+                conds_out[0] = operation(latent=conds_out[0])
+            return conds_out
+
+        m.set_model_sampler_pre_cfg_function(pre_cfg_function)
+        return (m, )
+
+class LatentOperationTonemapReinhard:
+    @classmethod
+    def INPUT_TYPES(s):
+        return {"required": { "multiplier": ("FLOAT", {"default": 1.0, "min": 0.0, "max": 100.0, "step": 0.01}),
+                              }}
+
+    RETURN_TYPES = ("LATENT_OPERATION",)
+    FUNCTION = "op"
+
+    CATEGORY = "latent/advanced/operations"
+    EXPERIMENTAL = True
+
+    def op(self, multiplier):
+        def tonemap_reinhard(latent, **kwargs):
+            latent_vector_magnitude = (torch.linalg.vector_norm(latent, dim=(1)) + 0.0000000001)[:,None]
+            normalized_latent = latent / latent_vector_magnitude
+
+            mean = torch.mean(latent_vector_magnitude, dim=(1,2,3), keepdim=True)
+            std = torch.std(latent_vector_magnitude, dim=(1,2,3), keepdim=True)
+
+            top = (std * 5 + mean) * multiplier
+
+            #reinhard
+            latent_vector_magnitude *= (1.0 / top)
+            new_magnitude = latent_vector_magnitude / (latent_vector_magnitude + 1.0)
+            new_magnitude *= top
+
+            return normalized_latent * new_magnitude
+        return (tonemap_reinhard,)
+
 NODE_CLASS_MAPPINGS = {
     "LatentAdd": LatentAdd,
     "LatentSubtract": LatentSubtract,
@@ -152,4 +228,7 @@ NODE_CLASS_MAPPINGS = {
     "LatentInterpolate": LatentInterpolate,
     "LatentBatch": LatentBatch,
     "LatentBatchSeedBehavior": LatentBatchSeedBehavior,
+    "LatentApplyOperation": LatentApplyOperation,
+    "LatentApplyOperationCFG": LatentApplyOperationCFG,
+    "LatentOperationTonemapReinhard": LatentOperationTonemapReinhard,
 }