Abstract: This paper proposes a new design of spatial FIR
filter to automatically detect water level from a video signal of
various river surroundings. A new approach in this report applies
"addition" of frames and a "horizontal" edge detector to distinguish
water region and land region. Variance of each line of a filtered
video frame is used as a feature value. The water level is recognized
as a boundary line between the land region and the water region.
Edge detection filter essentially demarcates between two distinctly
different regions. However, the conventional filters are not
automatically adaptive to detect water level in various lighting
conditions of river scenery. An optimized filter is purposed so that
the system becomes robust to changes of lighting condition. More
reliability of the proposed system with the optimized filter is
confirmed by accuracy of water level detection.
Abstract: This paper presents comparative study on recent
integer DCTs and a new method to construct a low sensitive structure
of integer DCT for colored input signals. The method refers to
sensitivity of multiplier coefficients to finite word length as an
indicator of how word length truncation effects on quality of output
signal. The sensitivity is also theoretically evaluated as a function of
auto-correlation and covariance matrix of input signal. The structure of
integer DCT algorithm is optimized by combination of lower sensitive
lifting structure types of IRT. It is evaluated by the sensitivity of
multiplier coefficients to finite word length expression in a function of
covariance matrix of input signal. Effectiveness of the optimum
combination of IRT in integer DCT algorithm is confirmed by quality
improvement comparing with existing case. As a result, the optimum
combination of IRT in each integer DCT algorithm evidently improves
output signal quality and it is still compatible with the existing one.