We present a new image compression method to improve visual perception of the decompressed images and achieve higher image compression ratio. This method balances between the compression rate and image quality by compressing the essential parts of the image-edges. The key subject/edge is of more significance than background/non-edge image. Taking into consideration the value of image components and the effect of smoothness in image compression, this method classifies the image components as edge or non-edge. Low-quality lossy compression is applied to non-edge components whereas high-quality lossy compression is applied to edge components. Outcomes show that our suggested method is efficient in terms of compression ratio, bits per-pixel and peak signal to noise ratio.
Abstract-Visual Simultaneous Localization And Mapping, (VSLAM) algorithms exploit the observation of scene naturallyexisting distinct features to infer the camera motion and build a map of a static environment. There is an increasing interest towards building efficient VSLAM algorithms mainly from computational perspectives; however, there may be insufficient clues to solve for SLAM parameters efficiently. In this paper, deliberate camera oscillations are superimposed on the camera main motion (robot motion), mostly in a lateral direction to give sufficient physical clues for the solution. Filtering methods exploit correlation to infer the motion parameters, and since oscillation introduces more local changes, it can enhance the estimation by correlation. Simulation results are presented showing the effects of oscillation parameters on visual SLAM performance in different motion scenarios. The results showed significant improvement of accuracy for oscillating camera over the steady camera case, and in several cases errors are reduced to less than half its value. These simulation results can be the basis to design a real experimental system.
During taxing, the aircraft can be treated as a three wheeled vehicle. This work deals with the dynamic behavior of this three-wheeled vehicle during the steering mode. Conventionally the hydraulic power steering systems incorporate either hydraulic or electrohydraulic servo-systems. Nevertheless, Part 1 of this paper deals with the dynamic behavior of a steering system incorporating three directional control valves of poppet type in one housing. A nonlinear mathematical model of the directional control valve assembly was developed and used to simulate the valves dynamic behavior. The validity of the simulation program was evaluated in the steady state by comparing simulation results with results of experimental work conducted on the studied valves. The construction of the mechanical parts is explained and the kinematics of the steering system was analyzed and presented. The transient response of the steering system incorporating the directional control valve assembly was calculated, presented and discussed.
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.