Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Entire DC Network
Contour Encoded Compression And Transmission, Christopher B. Nelson
Contour Encoded Compression And Transmission, Christopher B. Nelson
Theses and Dissertations
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 …
Vectorization Of Raster Images Using B-Spline Surfaces, Curtis A. Armstrong
Vectorization Of Raster Images Using B-Spline Surfaces, Curtis A. Armstrong
Theses and Dissertations
A system has been developed for converting raster images into vector images. Raster images are made of pixels, while vector images are made of smoother shapes. The image is first segmented, and the segments are layered. The boundary of each segment is approximated with a periodic B-Spline curve. This curve is then used to create a B-Spline surface to approximate the interior of the segment. The algorithm fits each B-Spline to the colors of the image using least-squares approximation. The color and shape of each B-Spline surface are extrapolated into regions behind other segments. The result is a vector image …