ComfyUI Pixel Grid Helpers

A suite of custom nodes for ComfyUI designed to assist with pixelized image generation and processing. These nodes provide functionality for color quantization, palette enforcement, and grid-based image cleaning without requiring external dependencies beyond the standard ComfyUI environment.

Installation

Method 1: ComfyUI Manager

1. Open ComfyUI Manager.
2. Search for "Pixel Grid Helpers".
3. Install the node pack and restart ComfyUI.

Method 2: Manual Installation

1. Navigate to your ComfyUI custom_nodes directory.
2. Clone this repository:

   git clone https://github.com/molbal/ComfyUI-PixelGridHelpers.git

Method 3: Comfy CLI Installation

1. Go to the ComfyUI Root directory
2. Execute:

comfy node install comfyui-pixelgrid-helpers

Restart ComfyUI and refresh the browser after installation.

Node Reference

1. Pixel Grid: Quantize (Max Colors)

Reduces the colors in an image to a specified maximum number (N) using K-Means clustering. It automatically generates a palette based on the image content.

• Inputs:
  • image: The input image.
  • max_colors: The target number of colors (e.g., 16).
• Outputs:
  • quantized_image: The image reduced to the target color count.
  • hex_palette: A comma-separated string of the generated HEX color codes.

2. Pixel Grid: Enforce Palette

Takes an input image and forces every pixel to match the nearest color in a provided HEX palette.

• Inputs:
  • image: The input image.
  • hex_palette: A comma-separated string of HEX codes (e.g., #FF0000, #00FF00, #0000FF).
• Outputs:
  • quantized_image: The image re-colored using only the provided palette.
  • hex_palette_out: Passthrough of the input string.

3. Pixel Grid: Merge Similar Colors

Merges colors that are visually similar based on a threshold. This is useful for cleaning up noise where multiple shades of the same color exist unintentionally in pixel art.

• Inputs:
  • image: The input image.
  • threshold: A float value (0.0 to 1.0) defining how close colors must be to merge. Higher values merge more colors.
• Outputs:
  • merged_image: The processed image.
  • hex_palette: The palette of the resulting image.

4. Pixel Grid: Analyze Palette

Analyzes an image and extracts all unique colors as a HEX string.

• Inputs:
  • image: The input image.
• Outputs:
  • hex_palette: A comma-separated string of all unique colors found in the image.

5. Pixel Grid: Palette to Image

Generates a visual representation of a color palette. It creates a vertical stack of 24x24 pixel color swatches based on the input HEX string.

• Inputs:
  • hex_palette: A comma-separated string of HEX codes.
• Outputs:
  • swatch_image: An image output showing the colors stacked vertically.

6. Pixel Grid: Median Fixer

Designed for upscaled pixel art where logical pixels (blocks) are comprised of smaller physical pixels (e.g., a 6x6 grid). It calculates the median color of each grid block to remove noise or upscaling artifacts.

• Inputs:
  • image: The input image.
  • grid_size: The size of the logical pixel grid (default: 6).
• Outputs:
  • downscaled_image: The image downscaled to its true resolution (1 pixel per logical block).
  • original_size_image: The image reconstructed at the original resolution, with clean, solid grid blocks.