Posterize Image
Controlled node
Overview
The Posterize Image node reduces the number of colors in an image to simulate a poster-like effect. This is useful for creating stylized images, reducing color complexity, or preparing images for specific printing processes. The node uses the Jimp image processing library to quantize the color palette of the input image.
The posterization effect works by reducing the number of distinct color levels in each RGB channel. For example, with a levels value of 2, each color channel (red, green, blue) is reduced to only 2 possible values (typically 0 and 255), resulting in a total of 8 colors (2³) in the final image.
Inputs
| Input | Type | Description | Default |
|---|---|---|---|
| Run | Event | Fires when the node starts processing the image. | - |
| Image | Data | The input image to be posterized. Must be a valid Jimp image object. | - |
| Levels | Number | Specifies the number of color levels per channel. Higher values retain more colors, lower values create more dramatic posterization effects. | 2 |
Outputs
| Output | Type | Description |
|---|---|---|
| Done | Event | Fires when the image processing is complete and the output is ready. |
| Output | Data | Contains the posterized image as a Jimp image object. |
Runtime Behavior and Defaults
When the node receives a Run event, it processes the input image immediately using the Jimp posterize() method. The node clones the input image before processing to avoid modifying the original.
The Levels parameter determines the number of distinct color values per RGB channel:
- A value of
2creates the most extreme posterization (2 values per channel, 8 total colors) - A value of
4creates a moderate effect (4 values per channel, 64 total colors) - Higher values approach the original image quality while still reducing color depth
If the Levels input is not connected or provided, the node defaults to 2.
Example Usage
Connect a Read Image node to the Image input to load an image from your library. Set the Levels input to control the intensity of the effect:
[Read Image] → [Posterize Image] → [Write To Library]
For a subtle posterization effect suitable for artistic filters, try setting Levels to 4 or 6. For a bold, graphic poster look suitable for print materials or stylized graphics, use the default value of 2 or 3.
You can also connect the Levels input to a Number node or variable to dynamically adjust the posterization level based on user input or other workflow conditions.