SLIC Algorithm

The SLIC (Simple Linear Iterative Clustering) algorithm is an advanced pixelation algorithm in Image2pixel that creates content-aware pixel art. Unlike the standard algorithm which creates uniform grid-based pixels, SLIC generates organic, shape-respecting pixel clusters.

How It Works

The SLIC algorithm works through these main steps:

  1. Superpixel Generation: The algorithm divides the image into irregular-shaped "superpixels" that adhere to natural boundaries in the image.
  2. Iterative Refinement: The superpixels are iteratively refined to better match the image content.
  3. Color Assignment: Each superpixel is assigned a representative color based on the pixels within it.
  4. Color Quantization: The number of colors is reduced to match the selected Color Count using a weighted color averaging technique.

The result is a stylized, content-aware pixel art that preserves important image features while still creating a distinct pixel art style.

Parameters

Region Size

Controls the approximate size of each superpixel region. Larger values create larger, more blocky regions, while smaller values create more detailed superpixels.

Value Effect Best For
5-15 Small superpixels, high detail preservation Detailed art, complex scenes
16-30 Medium superpixels, good balance General pixel art, portraits
31-50 Large superpixels, abstract appearance Stylized art, abstract effects

Compactness

Controls how much the algorithm prioritizes regular shapes versus adhering to color boundaries. Higher values create more uniform superpixels, while lower values create superpixels that better follow image features.

Value Effect Best For
1-10 Highly irregular shapes, strong feature adherence Images with distinct edges and features
11-30 Balanced shape regularity Most images, general purpose
31-50 More uniform, grid-like superpixels Creating a more traditional pixel art look

Iterations

Controls how many refinement passes the algorithm performs. More iterations lead to more precise superpixels but increase processing time.

Value Effect Processing Speed
1-3 Quick approximation, less refined superpixels Fast
4-7 Balanced refinement Moderate
8-10 Highly refined superpixels Slow

Colors

Determines the maximum number of colors in the output image.

Value Effect Best For
2-8 Highly limited color palette Simple, iconic pixel art
9-32 Moderate color palette Balanced pixel art with good color variety
33-96 Rich color palette Complex scenes, gradients, detailed pixel art

Transparency Support

The SLIC algorithm supports transparency in images. Transparent regions in the original image will remain transparent in the processed result, making it suitable for creating pixel art sprites and assets with transparent backgrounds.

Example Usage

Creating Organic-Looking Pixel Art

For natural-looking landscapes and organic subjects:

Creating Abstract Pixel Art

For stylized, abstract pixel art:

Creating Detailed Character Portraits

For character portraits with good detail preservation:

Comparison with Standard Algorithm

Feature SLIC Algorithm Standard Algorithm
Pixel Shape Irregular, content-aware shapes Uniform, grid-based squares
Detail Preservation Adaptive based on image content Uniform across the image
Edge Preservation Better preserves important edges May lose edge details in high-contrast areas
Parameter Complexity More complex (4 parameters) Simple (2 parameters)
Processing Speed Slower (especially with higher iteration counts) Faster
Best For Artistic pixel art, organic subjects Classic pixel art, game sprites

Tips for Best Results