A New Rotation Algorithm for Monochromatic Images
Bruno Avila, Rafael Lins, Lamberto Augusto

DOI: 10.14209/sbrt.2005.108
Evento: XXII Simpósio Brasileiro de Telecomunicações (SBrT2005)
Keywords: Monochromatic images rotation document image analysis skew correction critical points white holes uneven edges disconnection of the elements
The classical rotation algorithm whenever applied to monochromatic images degrades them by introducing white holes in black areas, making edges uneven and disconnecting neighboring elements. Several algorithms in the literature address only the white hole problem. They ignore both edge ripples and do not guarantee the connectivity of neighboring areas. This paper proposes a new algorithm that solves those three problems, producing better quality images and smaller compressed file size than its predecessors. It works by detecting and rotating the critical points of the each element of the image, connecting them using a line drawing algorithm and flood-filling each region.