In the past few years, programmable mediaprocessors (e.g., Hitachi/Equator Technologies MAP-CA and Texas Instruments TMS320C6x) have been replacing ASICs and other hardwired components in imaging applications (e.g., medical imaging modalities, machine vision systems, and video conferencing). Due to the high performance requirements of many imaging applications, older general-purpose processors were not suitable for these kinds of applications. For instance, in 1993 the TMS320C80 was about 50 times faster than the Intel 486 processor. However, recent advances in the architecture and instruction sets of general-purpose processors have closed the gap significantly in performance between these processors and programmable mediaprocessors. For example, the MMX, SSE, and SSE2 extensions to the Pentium 4 instruction set give the Pentium 4 a legitimate multimedia instruction set that is comparable to the instruction sets found in mediaprocessors, thus further blurring the boundary between general-purpose processors and mediaprocessors. The combination of the instruction set extensions and a new architecture that supports very high clock frequencies give the Pentium 4 performance in imaging functions comparable to high performance mediaprocessors and thereby make the Pentium 4 a candidate for applications where its large size, high cost, and high power consumption are not overriding issues.