The integral image is an image containing accumulated sums of pixel values taken from an input image. It is an important concept for multi-scale image processing algorithms, for it provides a very economic way to compute the sum of pixel values in any rectangular input image region.Unfortunately, the integral image requires a large binary word length to represent the accumulated sums. This is an issue for platforms having limited memory, power, and bandwidth like in mobile devices. Our paper deals with two methods for word length reduction, involving computation through the overflow and rounding with error diffusion. We show by experiment that, based on a word length reduced integral image, the Viola and Jones face detector for a VGA resolution can work on a 16-bit CPU (i.s.o. 27 bits, which becomes 32 bits on byte-oriented CPUs), enabling face detection on a wider range of platforms.

NFUS was effective in imaging RF catheter ablation lesion formation in real time. It was useful in assessing the dynamics of lesion growth and could visualize impending steam pops. It may be a useful technology to improve both safety and efficacy of RF catheter ablation.

Abstract-We consider orthonormal expansions where the basis functions are governed by some free parameters. If the basis functions adhere to a certain differential or difference equation, then an expression can be given for a specific enforced convergence rate criterion as well as an upper bound for the quadratic truncation error. This expression is a function of the free parameters and some simple signal measurements. Restrictions on the differential or difference equation that make this possible are given. Minimization of either the upper bound or the enforced convergence criterion as a function of the free parameters yields the same optimal parameters, which are of a simple form. This method is applied to several continuous-time and discrete-time orthonormal expansions that are all related to classical orthogonal polynomials.

Integrated US in an RF ablation catheter is able to visualize gas formation intramyocardially several seconds prior to a steam pop occurring. This technology may help prevent complications arising from steam pops.