A method for reduction of color space dimensionality by moment-preserving thresholding and its application in edge detection for color images is proposed. An input color image is partitioned into n x n non-overlapping blocks. A moment-preserving thresholding technique is then applied individually to each color plane of each image block. Two sets of (R, G, B) tristimulus values are obtained from...

Reasoning from image formation, we have shown that there exists a greyscale image – the invariant image – that depends only on the reflectances in the scene. Since illumination dependence is removed, one aspect of the invariant image is that shadows are effectively removed. Moreover, given either a calibration, or clean data with good noise statistics, this invariant is easily found. However, w...

Algorithmic skeletons in conjunction with list homomorphisms play an important role in formal development of parallel algorithms. We have designed a notion of homomorphism dedicated to bulk synchronous parallelism. In this paper we derive two application using this theory: sparse matrix vector multiplication and the all nearest smaller values problem. We implement a support for BSP homomorphism...

This paper presents a complete coding system for compression of natural color still images represented with 24 bits per pixel. The original 8-bit red, green, and blue (RGB) image components are rst transformed to a luminance (Y) and two chrominance components (Cb, Cr) according to the ITU-R Recommendation 601 1]. Each of the Y, Cb, and Cr tristimulus values are then decomposed separately in a s...

Fuzzy c-means clustering method for segmenting even the colour images is dealt with this work. Here the seegmentation method is based on a basic region growing method and uses membership grades’ of pixels to classify pixels into appropriate segments. The methodology incorporates the property of utilizing the extended feature space of an image to obtain better segmentation. Images which are in R...

Land use of sewage sludge is the primary disposal method in Shanxi, accounting for 42.66% of all. To determine the ecological risk of heavy metals in sewage sludge, contents of seven heavy metals in sewage sludge from 9 municipal waste water treatment plants (WWTPs) that had the highest application for land use were determined. The order of the measured concentrations was: Zn > Cr > Cu > Ni > P...

OBJECTIVE This in vitro study analyzed the effects of a bleaching treatment containing 35% hydrogen peroxide (HP) with or without calcium on bovine enamel, using the Knoop hardness number (KHN), tristimulus colorimetry (TC), and scanning electron microscopy. MATERIALS AND METHODS Forty-five specimens were randomly divided into groups (n = 5), which included artificial saliva (negative control...

From real spectroradiometric data, we propose an algorithm to obtain camera opto-electronic conversion functions (camera OECFs) for different values of the lens aperture N from the opto-electronic conversion spectral functions (OECSFs). Working in the linear range of the inverse OECFs, we have found that the slope vs. lens aperture function is fitted by a second order polynomial. This happens a...