Eiichi Sakaue

Scaleable resolution transformation with anti-aliasing by outlining with approximated B-spline curve and rerendering

This paper presents a developed scaleable resolution transformation method with high image quality, real-time processing and small circuitry. The progress of networked multi-functional hard-copy products for printing images from various sources such as facsimile machines, PCs, scanners and digital cameras, which have various resolutions, has created an urgent need for scaleable resolution transformation with high image quality.

Scalable resolution transformation by outlining with approximated B-spline curve

This paper presents a developed resolution transformation method which achieves scaleable resolution transformation of bi-level images with high image quality, real-time processing and small circuitry. The progress of networked multi- functional hard-copy products for printing images from various sources such as facsimile machines, PCs, scanners and digital cameras, which have various resolutions, has created an urgent need for scaleable resolution transformation with high image quality. The proposed method applies outlining and rendering to scaleable resolution transformation. Furthermore, it minimizes the size of the circuitry by modifying their algorithms. Outlines are generated from the bi-level bit map of the source image by fitting approximated B-spline curve upon edge pixels. The bi-level bit map image which has a different resolution is generated from the outlines with local rendering. Curve fitting of approximated B-spline curve and local rendering makes it possible to reduce the circuitry. As a result, real-time scaleable resolution transformation of high quality is achieved with small circuitry. The quality of images transformed from 200 dpi to 600 dpi by the proposed method is almost equivalent to a genuine 600 dpi image.