Eric Welch

Abstract

Many media processing algorithms suffer from long execution times, which are most often not acceptable from an end user point of view. Recently, this problem has been exacerbated because media has higher resolution. One possible solution is through the use of Single Instruction Multiple Data (SIMD) architectures, such as ARM's NEON. These architectures take advantage of the parallelism in media processing algorithms by operating on multiple pieces of data with just one instruction. SIMD instructions can significantly decrease the execution time of the algorithm, but require more time to implement. This thesis studies the use of SIMD instructions on a Cortex-A8 processor with NEON SIMD coprocessor. Both image processing algorithms, bilinear interpolation and distortion, are altered to process multiple pixels or colors simultaneously using the NEON coprocessor's instruction set. The distortion algorithm is also altered at the assembly level through the removal of memory accesses and branches, adding data prefetch instructions, and interlacing ARM and NEON instructions. Altering the assembly code requires a deeper understanding of the code and more time, but allows for more control and higher speedups. The theoretical speedup for the bilinear interpolation and distortion algorithms is three and four times respectively. The actual measured speedup for the bilinear interpolation algorithm is more than two times, and for the distortion algorithm is more than three times. The results show that SIMD instructions can provide a speedup to image processing algorithms following a correct sequence of modifications of the code.

Library of Congress Subject Headings

Signal processing--Digital techniques; Embedded computer systems; Multimedia systems; SIMD (Computer architecture)

Publication Date

12-1-2012

Document Type

Thesis

Department, Program, or Center

Microelectronic Engineering (KGCOE)

Advisor

Patru, Dorin

Comments

Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: TK5102.9 .W45 2012

Campus

RIT – Main Campus

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