What the Crystallize Effect Does in Paint.NET

The Crystallize effect in Paint.NET transforms standard digital images into stylized, mosaic-like artwork by grouping adjacent pixels into geometric, polygonal cells. Located under the Effects > Distort menu, this tool redistributes color data across defined areas, replacing fine photographic detail with flat-shaded facets resembling stained glass, frosted glass, or mineral crystals.

Grouping Pixels into Voronoi Cells

At its core, the Crystallize effect mathematically groups clusters of nearby pixels into distinct polygons using an algorithm similar to a Voronoi diagram. Instead of rendering individual pixels along a continuous gradient, the effect establishes a series of seed points across the canvas and binds all surrounding pixels within a specific radius to the nearest seed point.

Color Averaging

Once the pixel clusters are mapped into their respective geometric boundaries, the effect samples the colors of the original pixels contained within each cluster. It calculates the average color value of that group and applies it uniformly to the entire polygon. This eliminates smooth transitions, sharp lines, and fine textures, replacing them with flat, solid-colored facets that mirror the dominant tones of the original composition.

Controlling Cluster Size

The primary control for the Crystallize effect is the Cell Size slider, which dictates how pixel clusters are processed:

• Small Cell Size: Pixels are grouped into tiny clusters, producing thousands of miniature facets. This retains the recognizable shapes, edges, and overall structure of the original image while giving it a subtle textured or frosted appearance.
• Large Cell Size: Pixels are gathered into wide clusters, producing large, broad polygons. This drastically reduces the image's resolution into an abstract composition of color blocks, obscuring fine details entirely.

Practical Applications

By altering pixel clusters in this way, the Crystallize effect is commonly used to create abstract graphic backgrounds, simulate retro low-poly art styles, or obscure sensitive information such as faces, text, and license plates without using standard blurring techniques.