Contour Encoded Compression and Transmission

• Main Author: Nelson, Christopher B.
• Format: Others
• Published: BYU ScholarsArchive 2006
• Subjects: image; compression; contour; computer; genealogy; Computer Sciences
• Online Access: https://scholarsarchive.byu.edu/etd/1096; https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2095&context=etd

As the need for digital libraries, especially genealogical libraries, continues to rise, the need for efficient document image compression is becoming more and more apparent. In addition, because many digital library users access them from dial-up Internet connections, efficient strategies for compression and progressive transmission become essential to facilitate browsing operations. To meet this need, we developed a novel method for representing document images in a parametric form. Like other “hybrid" image compression operations, the Contour Encoded Compression and Transmission (CECAT) system first divides images into foreground and background layers. The emphasis of this thesis revolves around improving the compression of the bitonal foreground layer. The parametric vectorization approach put forth by the CECAT system compares favorably to current approaches to document image compression. Because many documents, specifically handwritten genealogical documents, contain a wide variety of shapes, fitting Bezier curves to connected component contours can provide better compression than current glyph library or other codebook compression methods. In addition to better compression, the CECAT system divides the image into layers and tiles that can be used as a progressive transmission strategy to support browsing operations.