[Added] Nodes for normalization

Useful for testing models or using low level models

README.md

@@ -20,6 +20,9 @@ Currently we just have a few nodes used by other nodes I maintain.
   - [Image Download and Load](#1-image-download-and-load)
   - [Face Composite](#2-face-composite)
   - [Face Composite (frame by frame)](#3-face-composite-frame-by-frame)
+  - [Normalize Image to ImageNet](#4-normalize-image-to-imagenet)
+  - [Normalize Image to [-0.5, 0.5]](#5-normalize-image-to-05-05)
+  - [Normalize Image to [-1, 1]](#6-normalize-image-to-1-1)
 - 📝 [Usage Notes](#-usage-notes)
 - 📜 [Project History](#-project-history)
 - ⚖️ [License](#️-license)
@@ -81,6 +84,50 @@ Currently we just have a few nodes used by other nodes I maintain.
    - **How it Works:** The node iterates from frame 0 to N-1. In each step, it takes the i-th `animated` frame and the i-th `reference` frame. It then pastes the animated frame onto the reference frame using the coordinates from the single, static bounding box.
 
 
+### 4. Normalize Image to ImageNet
+   - **Display Name:** `"Normalize Image to ImageNet`
+   - **Internal Name:** `SET_NormalizeToImageNetDataset`
+   - **Category:** `image/normalization`
+   - **Description:** Normalizes an image tensor using the mean and standard deviation of the ImageNet dataset.
+   - **Purpose:** Essential for pre-processing images before feeding them into models that were pre-trained on ImageNet (e.g., most ResNet, VGG, EfficientNet models).
+   - **Inputs:**
+     - `image` (`IMAGE`): A standard ComfyUI image tensor in the `[0, 1]` range.
+   - **Output:**
+     - `image` (`IMAGE`): The normalized image tensor. The value range will be altered significantly.
+   - **How it Works:**  For each channel, it performs the operation `output = (input - mean) / std`, using the standard ImageNet values:
+    - **Mean:** `[0.485, 0.456, 0.406]`
+    - **Std Dev:** `[0.229, 0.224, 0.225]`
+
+### 5. Normalize Image to [-0.5, 0.5]
+
+- **Display Name:** `Normalize Image to [-0.5, 0.5]`
+- **Internal Name:** `SET_NormalizeToMinus05_05`
+- **Category:** `image/normalization`
+- **Description:** Normalizes an image tensor by centering its values around zero.
+- **Purpose:** Useful for models trained from scratch or those that expect input data in the `[-0.5, 0.5]` range. This can help stabilize training.
+- **Inputs:**
+  - `image` (`IMAGE`): A standard ComfyUI image tensor in the `[0, 1]` range.
+- **Output:**
+  - `image` (`IMAGE`): The normalized image tensor, with values in the `[-0.5, 0.5]` range.
+- **How it Works:** For each channel, it performs the operation `output = (input - mean) / std`, using:
+  - **Mean:** `[0.5, 0.5, 0.5]`
+  - **Std Dev:** `[1.0, 1.0, 1.0]`
+
+### 6. Normalize Image to [-1, 1]
+
+- **Display Name:** `Normalize Image to [-1, 1]`
+- **Internal Name:** `SET_NormalizeToMinus1_1`
+- **Category:** `image/normalization`
+- **Description:** Normalizes an image tensor to the `[-1, 1]` range.
+- **Purpose:** A common requirement for certain model architectures, particularly Generative Adversarial Networks (GANs) and models using the `tanh` activation function in their output layer.
+- **Inputs:**
+  - `image` (`IMAGE`): A standard ComfyUI image tensor in the `[0, 1]` range.
+- **Output:**
+  - `image` (`IMAGE`): The normalized image tensor, with values in the `[-1, 1]` range.
+- **How it Works:** For each channel, it performs the operation `output = (input - mean) / std`, using:
+  - **Mean:** `[0.5, 0.5, 0.5]`
+  - **Std Dev:** `[0.5, 0.5, 0.5]`
+
 ## 🚀 Installation
 
 You can install the nodes from the ComfyUI nodes manager, the name is *Image Misc*, or just do it manually:

src/nodes/nodes_img.py

@@ -11,6 +11,7 @@ from seconohe.downloader import download_file
 # We are the main source, so we use the main_logger
 from . import main_logger
 import torch
+import torchvision.transforms.functional as TF
 from typing import Optional
 try:
     from folder_paths import get_input_directory   # To get the ComfyUI input directory
@@ -29,6 +30,7 @@ logger = main_logger
 BASE_CATEGORY = "image"
 IO_CATEGORY = "io"
 MANIPULATION_CATEGORY = "manipulation"
+NORMALIZATION = "normalization"
 
 
 def tensor_to_pil(tensor: torch.Tensor) -> Image.Image:
@@ -315,3 +317,73 @@ class CompositeFaceFrameByFrame(CompositeFace):
         final_batch = torch.stack(output_images)
 
         return (final_batch,)
+
+
+class NormalizeToImageNetDataset():
+    """
+    A ComfyUI node to normalize the values to the mean/std of the ImageNet dataset
+    """
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "image": ("IMAGE",),
+            },
+        }
+    RETURN_TYPES = ("IMAGE",)
+    RETURN_NAMES = ("image",)
+    FUNCTION = "normalize"
+    CATEGORY = BASE_CATEGORY + "/" + NORMALIZATION
+    DESCRIPTION = ("Normalize the image to the ImageNet dataset")
+    UNIQUE_NAME = "SET_NormalizeToImageNetDataset"
+    DISPLAY_NAME = "Normalize Image to ImageNet"
+    imagenet_normalize = None
+
+    def normalize(self, image: torch.Tensor):
+        return (TF.normalize(image.permute(0, 3, 1, 2),  # BHWC -> BCHW
+                             mean=[0.485, 0.456, 0.406],
+                             std=[0.229, 0.224, 0.225]).permute(0, 2, 3, 1),)  # BCHW -> BHWC
+
+
+class NormalizeToRangeMinus05to05():
+    """
+    A ComfyUI node to normalize the values to the [-0.5, 0.5] range
+    """
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {"required": {"image": ("IMAGE",), }, }
+    RETURN_TYPES = ("IMAGE",)
+    RETURN_NAMES = ("image",)
+    FUNCTION = "normalize"
+    CATEGORY = BASE_CATEGORY + "/" + NORMALIZATION
+    DESCRIPTION = ("Normalize the image to [-0.5, 0.5]")
+    UNIQUE_NAME = "SET_NormalizeToRangeMinus05to05"
+    DISPLAY_NAME = "Normalize Image to [-0.5, 0.5]"
+    imagenet_normalize = None
+
+    def normalize(self, image: torch.Tensor):
+        return (TF.normalize(image.permute(0, 3, 1, 2),  # BHWC -> BCHW
+                             mean=[0.5, 0.5, 0.5],
+                             std=[1.0, 1.0, 1.0]).permute(0, 2, 3, 1),)  # BCHW -> BHWC
+
+
+class NormalizeToRangeMinus1to1():
+    """
+    A ComfyUI node to normalize the values to the [-1, 1] range
+    """
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {"required": {"image": ("IMAGE",), }, }
+    RETURN_TYPES = ("IMAGE",)
+    RETURN_NAMES = ("image",)
+    FUNCTION = "normalize"
+    CATEGORY = BASE_CATEGORY + "/" + NORMALIZATION
+    DESCRIPTION = ("Normalize the image to [-1, 1]")
+    UNIQUE_NAME = "SET_NormalizeToRangeMinus1to1"
+    DISPLAY_NAME = "Normalize Image to [-1, 1] (i.e. GAN)"
+    imagenet_normalize = None
+
+    def normalize(self, image: torch.Tensor):
+        return (TF.normalize(image.permute(0, 3, 1, 2),  # BHWC -> BCHW
+                             mean=[0.5, 0.5, 0.5],
+                             std=[0.5, 0.5, 0.5]).permute(0, 2, 3, 1),)  # BCHW -> BHWC