# Rotation and scale invariant image watermarking based on polar harmonic transforms

> Research article (Optik, 2019) · cited 35× · AI/ML

**Wikidata**: [openalex:W2911963588](https://www.wikidata.org/wiki/openalex:W2911963588)  
**Source**: https://4ort.xyz/entity/rotation-and-scale-invariant-image-watermarking-based-on-polar-harmonic-transforms