Jianzhong Cao

Multifocus Noisy Image Fusion Algorithm Using the Contourlet Transform

Multifocus image fusion deals with a stack of images that were acquired with a different focus point to get an image with all the objects in the scene full focused. Considered the noise effect, in this paper, we proposed a multifocus noisy image fusion algorithm using the contourlet transform. Utilizing the captured directional information by the contourlet transform, the directional windows are used to determine the fusion weight. The experiment results demonstrate the higher performance of the proposed multifocus noisy image fusion algorithm compared to the wavelet-based multifocus noisy image fusion method

Optimization of PID Parameters Based on Improved Particle-Swarm-Optimization

Because the PID parameter settings obtained by classical method fail to achieve the best control performances, this paper proposes an improved particle swarm optimization (IPSO) algorithm with non-linear inertial weight changes and border buffer. Unlike the original PSO, the inertial weight changes instead of linearly. In addition, we provide a border buffer to the slopping-over particles, making them to fall in the explored space of optima to enhance the diversity of the particle swarm. The simulation experiments show that the system whose parameters are optimized by IPSO has better performances. Meanwhile, it proves the effectiveness of the improved particle swarm optimization.

A robust image registration algorithm used for panoramic image mosaic

The panoramic image has been widely used in social production, and has become an important topic in research on the field of image processing. For complex images with multiple scenes and other elements, the algorithm that is based on Harris cannot make image registration effectively. This paper proposes a method that combines Harris with SIFT, using the Harris algorithm with adaptive threshold to extract the corners and the SIFT descriptor to make the registration. It improved registration efficiency sub-effectively for the image in complex scenes, and generated a 360-degree panoramic image quickly. The experiments showed that the algorithm is adaptable and robust.

The research of the high precision universal stable reconnaissance platform in near space

The appliance of military was recognized more and more ,It is important that pod can bear the weight of the availability payload achieve the observation to the earth in 20km-100km area and work in the all-weather. The stable platform can load high imaging spectrometer, the thermal infrared imager, the infrared radiometer, the millimeter waves radar, the laser weapon and so on,in order to realize reconnaissance and attacking integrative and warning the long-distant missile. The stabilization accuracy of platform is prior to 20μrad and burden heavy load to the best of ones abilities. It used high precision velocity and acceleration gyroscope to fulfill the stabilization of the platform. Light-weight design by using new composite material and optimizing design. It was adapt to the near space environment better by structure design and simulation analysis.Enhance its basic frequency and sure the rigid of the frame platform .In addition, the structure of platform apply the two-axis and four-frame and use the method of FEA to fulfill the optimum design in order to attain the object of light-weight.In consider to the precision of the platform I establish the math model and make use of the monte carlo method to appraise and analysis the error that affect the precision of the platform. After emulating by the software of the Matlab to verify the results. It is apply the method that link the platform and aerocraft by mounting the no angular displacement shock absorbers on the elevator mechanism. This kind of design insulate the angular vibration and minish the linear vibration to ensure the image quality.

Design of high ratio middle infrared continuous zoom optical system

In recent years, the demand for infrared zoom systems is increasing in proportion with the development of infrared technology and its applications. To meet this demand a variety of zoom lenses have been designed. Infrared cameras operating in the 3-5μm spectral band are used in a wide variety of applications such as targeting, rescue, guidance and surveillance systems as well as other equipment. This paper using cool 320×240 detector with staring focal plane array and secondary imaging, a mid-wave optical system using mechanical-compensated with large-aperture and a zoom range of 10:1 is designed. The Pixel Dimensions of the detector is 30μm, and the wavelength between 3.7μm ~4.8μm.The system adopts negative group variable times and positive group of compensation which can realize 33mm~330mm continuous zoom and FOV =20.61°~2.08° ,it consists of 7 lenses including 3 aspheric surface. The length of the system is 262mm with the reflection mirror multipass optical path. The results show that the modulation transfer function(MTF)are above 0.4 within the whole focal range at spatial frequency of 17 lp/mm, and Root Mean Square (RMS) value of spot diameter were smaller than the Pixel Dimensions. After the image quality being optimized, the narcissus analysis is done and 100% cold shield efficiency is obtained. Finallythe monotonic and smooth Cam curve is given. The curve shows that the imaging plane is stable and the cam is easy to process. The system has advantages of simple structure, high image quality and short zoom path etc.

A novel ACM for segmentation of medical image with intensity inhomogeneity

This paper presents a scheme of improvement on the Lis model in terms of intensity inhomogeneous images. By introducing local entropy to Lis model, our method is able to segment medical images with intensity inhomogeneity and estimate the bias field simultaneously. The level set energy function is redefined as a weighted energy integral, where the weight is local entropy deriving from a grey level distribution of image. The total energy functional is then incorporated into a level set formulation. Experimental results on test images show that our approach outperforms the existing locally statistical active contour model (LSACM) and Lis model in terms of accuracy and efficiency with less central processing unit (CPU) time.

A novel real-time method for high dynamic range image tone mapping

Tone-mapping technique which can convert high dynamic range (HDR) to low dynamic range (LDR) images provides accurately visualization of HDR images on standard LDR displays. Most of the existing tone-mapping method could not realize real time processing while preserving good visualization. Utilizing an adaptive three-section lookup table, this paper proposes an effective, high quality, real time technique to convert 12-bit images to 8-bit image which can preserve abundant details and high contrast simultaneously. Experiment results show that this method can improve the weak signals of the image greatly, and the low luminance details can be observed distinctly on an 8-bit monitor.

Accurate measuring temperature with infrared thermal imager in the unstable condition of ambient temperature

The infrared thermal imaging systems are widely used for distinguishing target radiation temperature difference and they can also be used to measure the absolute temperature of the target. There may be great difference between the true value and the measurement results in the actual application of the infrared thermal imaging systems, just because of the unstable condition and the lack of compensation of the imagers own heat radiation. In order to obtain the accurate temperature of the target in some special conditions, such as aircraft internal and pilotless platform, we present a stationary infrared thermal imaging system to gather the goal gradation images and a method to compensate the influence of the imagers own heat radiation and the unstable condition. In radiation calibration experiment, we establish corresponding relationships between the gradation difference and the temperature difference by using a goal blackbody and a cooperation calibration blackbody between 0°C and 150°C. We also analysis the relationships mentioned above under the normal temperature and the high temperature separately. The results show that the proposed method may be useful in increasing the temperature measurement precision.

Non-contact heart rate measurements based on skin detection

Non-contact measurements of the cardiac pulse of humanity is always a challenging problem. Almost all the existing research work concentrates on heart rate measurements based on video recordings of the human face, in which the subject is restricted rigidly. In this paper, we propose a novel approach based on skin detection method. The skin regions in color video recordings are generalized to anywhere of the human body, not limited to human face. The skin detector and a chrominance-based technique are firstly used to detect the photo-plethysmo-graphy (PPG) signal. Then, we use an empirical parameter selection method to get the final heart rate estimation. The experiment results show the effectiveness of the proposed method.

Target measurement in elliptical orbit using generalized voxel coloring

Measurement of 3D scene from image sequences is necessary for many computer vision applications. In this paper, we identify the volumetric scene reconstruction as a critical issue for target measurement and use the statistical method to estimate the size of the reconstructed target. The proposed approach unifies the view volume in volumetric scene reconstruction while we only know the location information of the camera relative to the target in elliptical orbit. Experimental results on elliptical orbit with 200 meters long axis and 100 meters short axis illustrate that the average error is about 44 millimeters, which meets the accuracy requirement of general measurement.