—In this paper, we propose two architectures for the direct two–dimensional (2-D) discrete wavelet transform (DWT). The first one is based on a modified recursive pyramid algorithm (MRPA) and performs a " nonstandard " decomposition (i.e., Mallat's tree) of an image in approximately 2 2 3 clock cycles (ccs). This result consistently speeds up other known… (More)
3179  T. Yang and K. Yao, " Numerical error control in sliding window systems under finite precision arithmetics, " submitted for publication.  T. C. Yang, " Finite precision error control and array implementation of signal processing algorithms, " Ph. Dual-state systolic architecture for recursive least-squares updating and downdating, " in Proc.… (More)
—Rail inspection is a very important task in railway maintenance and it is periodically needed for preventing dangerous situations. Inspection is operated manually by trained human operator walking along the track searching for visual anomalies. This monitoring is unacceptable for slowness and lack of objectivity, because the results are related to the… (More)
—In this paper, we present our proposed architecture (PA) for the direct two-dimensional discrete wavelet transform (DWT), which performs a complete dyadic (i.e., nonstandard) decomposition of an 0 0 image in approximately 2 0 4 clock cycles (ccs). Therefore, it consistently speeds up the performance of other known architectures, which commonly need… (More)
—In this paper, we propose two scalable architectures (say, Arc and Arc 2) that perform the discrete wavelet transform (DWT) of an 0-sample sequence in only 0 2 clock cycles. Therefore, they are at least twice as fast as the other known archi-tectures. Also, they have an AT 2 parameter that is approximately 1/2 that of already existing devices. This result… (More)
ÐThis paper presents a modular algorithm which is suitable for computing a large class of multidimensional transforms in a general purpose parallel environment without interprocessor communication. Since it is based on matrix-vector multiplication, it does not impose restrictions on the size of the input data as many existing algorithms do. The method is… (More)
The railway maintenance is a particular application context required in order to prevent any dangerous situation.
I n this paper we propose a specialized hardware architecture for the real time visual navigation of a mobile robot. The adopted navigation method is based on a two-steps approach. Features are extracted and matched over an image sequence which is captured by a video-camera (mounted on a mobile robot) during its motion. As a result, a 2D motion field is… (More)