This thesis describes and implements an algorithmic framework for memory efficient, 'on-the-fly' halftoning in a progressive transmission environment. Instead of a conventional approach which repeatedly reconstructs the continuous tone image from memory and subsequently halftones it for display, the proposed method achieves significant memory efficiency by storing only the halftoned image and updating it in response to additional information received through progressive transmission. Thus the method requires only a single frame-buffer of bits for storage of the displayed binary image and no additional storage is required for the contone data. The additional image data received through progressive transmission is accommodated through in-place updates of the buffer. The method is thus particularly advantageous for high resolution bi-level displays where it can result in significant savings in memory. The proposed framework is implemented using a suitable multi-resolution, multi-level modification of error diffusion that is motivated by the presence of a single binary frame-buffer. Aggregates of individual display bits constitute the multiple output levels at a given resolution. This creates a natural progression of increasing resolution with decreasing bit-depth. Output images are shown to be comparable in terms of quality to those obtained from the conventional Floyd Steinberg error diffusion algorithm.

Library of Congress Subject Headings

Image transmission; Image processing--Digital techniques; Photoengraving--Halftone process; Algorithms

Publication Date


Document Type


Student Type


Degree Name

Electrical Engineering (MS)

Department, Program, or Center

Electrical Engineering (KGCOE)


Guarav Sharma

Advisor/Committee Member

Sohail Dianat

Advisor/Committee Member

Eli Saber


Physical copy available from RIT's Wallace Library at TK5105.2 .M84 2004


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