Ulate the mechanism of frequency bandwidth adjustment and achieves precisely the same

Aus KletterWiki
Wechseln zu: Navigation, Suche

The illustration and formula of Gabor Ibrutinib site filter are shown in Fig. For every single channel image, Gabor Wavelet is employed to decompose the channel into different feature maps corresponding to unique frequency bands. After whitening and fusion, one or two nearby saliency maps corresponding to particular frequency bands are selected to produce the final saliency map. Every single step in diagram title= bmjopen-2014-007528 of the algorithm is shown in Fig. two. Gabor decomposition With regard to diverse categories of wavelet functions, Gabor function is adopted here to carry out decomposition because it is related to the procedure, that is also employed by Itti's NVT model to analyze the orientation data, of easy cells within the primary visual cortex. Additionally, the low-frequency elements of Gabor wavelet domain are maintained. The illustration and formula of Gabor filter are shown in Fig. three and Eq. (two), respectively.Fig. 2 Diagram of your algorithmCogn Neurodyn (2016) 10:255?Fig. three Five Gabor 2D filters (top rated row) with their corresponding amplitude spectrum (bottom row). From left to correct low-frequency element, highfrequency component with 0 ; 45 ; 90 ; 135 orientationsFig. four Illustration of Gabor decomposition and relationships in between function maps and bands. a High-frequency sub function maps and low-frequency function maps. b Corresponding frequency domainTherefore, 2D Gabor filter in lieu of Rapid Wavelet Decomposition is employed to achieve wavelet decomposition to be able to get additional facts on orientations. The 2D Gabor function is: 02 x ?y02 x0 g ; y; k; h; r??exp ?cos 2p ??2r2 k exactly where x0 ?x cos h ?y sin h, y0 ? sin h ?y cos h, and h ?f0 ; 45 ; 90 ; 135 g. And k may be the wavelength, r2 will be the variance of your Gaussian envelope. 4 title= hr.2012.7 band pass filters and a single low pass filter (when k approaches to infinity), with each other amount to five 2D Gabor filters. These 5 Gabor filters can practically cover the entire frequency domain at each and every scale. They're shown in Fig. three. The diagram of Gabor decomposition with three scales in 1 channel is shown in Fig. four plus the relationships in between spatial feature maps (Fig. 4a) and spectral bands (Fig. 4b) are also illustrated. Please note that the actual sizes of function maps fBx are half of those of fAx and fCx are also half of these of fBx title= scan/nst085 , for x ?1; 2; three; 4 and sizes of feature maps in the very same scale are equal. Given that these function maps correspond to a variety of frequency components, selections created on these maps are equivalent to these produced on frequency elements. Consequently, this approach calculates saliency primarily based on the feature maps in spatial domain. Inside the following sections, feature maps are applied to represent frequency bands.For Eq. (2), h ?f0 ; 45 ; 90 ; 135 g as well as the scale is r ?7=5. The low-pass 2D Gabor filter sets k a big quantity like klow ?two:510 , and four other high-pass ones set khigh ?two:five. The sizes of these filters are 15 ?15 pixels (shown in Fig. three). Experimental results indicate that saliency map computation is insensitive to the parameters of Gabor filters, as long as the 5 Gabor filters could cover the entire frequency domain.