With the rapid development of computers and the increasing, mass use of high-tech mobile devices, vision-based face recognition has advanced significantly. However, it is hard to conclude that the performance of computers surpasses that of humans, as humans have generally exhibited better performance in challenging situations involving occlusion or variations. Motivated by the recognition method of humans who utilize both holistic and local features, we present a computationally efficient hybrid face recognition method that employs dual-stage holistic and local feature-based recognition algorithms. In the first coarse recognition stage, the proposed algorithm utilizes Principal Component Analysis (PCA) to identify a test image. The recognition ends at this stage if the confidence level of the result turns out to be reliable. Otherwise, the algorithm uses this result for filtering out top candidate images with a high degree of similarity, and passes them to the next fine recognition stage where Gabor filters are employed. As is well known, recognizing a face image with Gabor filters is a computationally heavy task. The contribution of our work is in proposing a flexible dual-stage algorithm that enables fast, hybrid face recognition. Experimental tests were performed with the Extended Yale Face Database B to verify the effectiveness and validity of the research, and we obtained better recognition results under illumination variations not only in terms of computation time but also in terms of the recognition rate in comparison to PCA- and Gabor wavelet-based recognition algorithms.
While electrical conductivity (EC) and sodium adsorption ratio are commonly used to assess soil salinity, for detecting salinity responses during a growing season, those indicators appear to be insensitive when the soils are already high in salinity. We found that the EC and chloride concentrations in soil extracts from salt-affected greenhouses did not show a significant difference in response to different fertilizations of tomato (with a high N demand and a low susceptibility to salinity) and lettuce (the opposite) over the growing season. The fields had been treated with chemical fertilizers or chemical fertilizers plus manure composts combined with food wastes to investigate salinity enhancement by the amendments. On the other hand, the regression lines between EC and chloride concentration could show differential responses in both soil and plant extracts to the doses and salinities of fertilizers. Therefore, using the relationships between EC and associated ions can provide a better insight into the salinity susceptibilities of soils and plants.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.