blurin

Blurin is a term used in digital imaging to describe an adaptive blur technique that varies blur strength across an image to preserve edges while smoothing textures. In contrast to uniform Gaussian blur, blurin applies stronger smoothing in low-detail regions and weaker smoothing near high-contrast edges, producing a softened yet structured appearance.

Technique: Implementation typically relies on edge information, such as an edge map or gradient magnitude, to guide a blur operation. Methods may include bilateral-like filters, guided filtering, or region-based segmentation, with parameters controlling overall blur strength, edge sensitivity, and the spatial extent of smoothing. The goal is to reduce noise and textures without erasing important contours.

Applications: Blurin is used in privacy-preserving image processing to obscure faces and identification features while retaining scene form, in artistic post-production to achieve a painterly or dreamlike look, and in real-time graphics to simulate depth of field without a full 3D renderer. It also appears in tutorials and workflows as a more controlled alternative to global blur.

Variations and related terms: Variants include selective blur, edge-preserving blur, and motion-inspired blurin, which mimics motion blur along directional edges. Blurin is closely related to (but distinct from) conventional blur filters such as Gaussian blur and box blur, and to edge-preserving smoothing techniques like the bilateral filter or the guided filter.

Etymology and usage: The term blends blur with the suffix -in, popular in digital art parlance. It is not standardized in formal imaging literature but appears in tutorials and discussion forums as a descriptive label for adaptive blur techniques.

See also: Blur, Gaussian blur, edge-preserving smoothing, bilateral filter, guided filter.