Object tracking is a challenging research task due to target appearance variation caused by deformation and occlusion. Keypoint matching based tracker can handle partial occlusion problem, but it’s vulnerable to matching faults and inflexible to target deformation. In this paper, we propose an innovative keypoint matching procedure to address above issues. Firstly, the scale and orientation of corresponding keypoints are applied to estimate the target’s status. Secondly, a kernel function is employed in order to discard the mismatched keypoints, so as to improve the estimation accuracy. Thirdly, the model updating mechanism is applied to adapt to target deformation. Moreover, in order to avoid bad updating, backward matching is used to determine whether or not to update target model. Extensive experiments on challenging image sequences show that our method performs favorably against state-of-the-art methods.
We present a straightforward brightness preserving image enhancement technique. The proposed method is based on an original gradient and intensity histogram (GIH) which contains both gradient and intensity information of the image. This character enables GIH to avoid high peaks in the traditional intensity histogram and, thus alleviate overenhancement in our enhancement method, i.e., gradient and intensity histogram equalization (GIHE). GIHE can also enhance the gradient strength of an image, which is good for improving the subjective quality since the human vision system is more sensitive to the gradient than the absolute intensity of image. Considering that brightness preservation and dynamic range compression are highly demanded in consumer electronics, we manipulate the intensity of the enhanced image appropriately by amplifying the small intensities and attenuating the large intensities, respectively, using a brightness preserving function (BPF). The BPF is straightforward and universal and can be used in other image enhancement techniques. We demonstrate that the proposed method can effectively improve the subjective quality as well as preserve the brightness of the input image.
In the engineering project, arbitrary waveform generator controlled by software interface is needed by simulation and
test. This article discussed the program using the SCPI (Standard Commands For Programmable Instruments) protocol
and the VISA (Virtual Instrument System Architecture) library to control the Agilent signal generator (Agilent N5182A)
by instrument communication over the LAN interface. The program can conduct several signal generations such as CW
(continuous wave), AM (amplitude modulation), FM (frequency modulation), ΦM (phase modulation), Sweep. As
the result, the program system has good operability and portability.