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Image coding based on integer wavelet and embedded optimal coefficient scaling

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Chinese Optics Letters 2012年第B06期10卷 97-100页

作者：张立保杨凯娜 College of Information Science and Technology Beijing NormM University Beijing 100875 China State Key Laboratory of Remote Sensing Science Beijing Normal University Beijing 100875 China

Integer wavelet transform （IWT） could offer the lower computational complexity and the less storage spending for image compression than the discrete wavelet transform （DWT）. But the most coefficients of the IWT image have smaller dynamic change ranges than discrete wavelet transform. In this letter, an efficient and low-complerity coding algorithm called embedded optimal coefficient scaling （EOCS） is proposed. It optimizes the distribution of the wavelet coefficients in every threshold plane and provides an efficient embedded quadtree-partitioning scheme to encode the image. Experimental results show that the presented method cannot provide peak signal-to-noise ratio （PSNR） performance up about 2~6 dB better than set partitioning in hierarohical trees （SPIHT） without the OCSF scheme, but also support both efficiently lossy and lossless compression in single bitstream.

关键词： 100.2000 Digital image processing 100.3008 Image recognition, algorithms and filters 280.0280 Remote sensing and sensors

Linear camera calibration and pose estimation from vanishing points

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Chinese Optics Letters 2012年第B06期10卷 83-87页

作者：储珺王丽冯瑞娜张桂梅 Software College of Nanehang Hangkong University Nanchang 330063 China Aviation Manufacturing Engineering College of Nanchang Hangkong University Nanchang 330063 China Aircraft Engineering College of Nanchang Hangkong University Nanchang 330063 China

In order to broaden the scope of application and ensure the calibration precision, a new method of linear calibration by making fully use of vanishing point attributes is proposed. The method dose not need any rigorous restrictions, and solves the self-calibration problem with only five vanishing points in two digital images, which are arbitrarily taken by a handheld digital camera. Furthermore, another approach for camera＇s pose estimation is also put forward without any strict controlled motions. The experimental results of both computer simulation and real images show that the calibration algorithm is effective, feasible, and robust.

关键词： 100.2000 Digital image processing 100.2960 Image analysis 100.6890 Three-dimensional image processing

Foreground object extraction through motion segmentation

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Chinese Optics Letters 2015年第13期13卷 27-31页

作者：张印辉何自芬 Faculty of Mechanical and Electrical Engineering Kmm2ing University of Science and Technology Kunming 650500 China

We present a method to extract foreground object regions efficiently from image sequences. Scale-invariant feature transform algorithm is adopted to estimate the descriptor firstly by matching between two consecutive frames. Given local descriptor nmtching results, dense motion vector of each pixel is calculated by large displacement optical flow with variational optimization, which integrates detailed dcscriptors into the variational model. Then the foreground object boundaries and regions are detected by computing the optical flow gradient and magnitude. Experiments demonstrate that the method can achieve better segmentation results than alternative ,nethods and adapts well to moving objects in relatively stationary hackgronnd image sequences.

关键词： 100.2000 Digital image processing 100.2960 Image analysis

Adaptive image enhancement using nonsubsampled contourlet transform domain histogram matching

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Chinese Optics Letters 2014年第A02期12卷 36-39页

作者：周妍李庆武霍冠英 College of lOT Engineering Hohai University Changzhou 213022 China Changzhou Key Laboratory of Sensor Networks and Environmental Sensing Changzhou 213022 China

In this letter, we propose a novel adaptive image enhancement algorithm based on nonsubsampled contourlet transform （NSCT） coefficient histogram matching. Firstly, the original image is decomposed in the NSCT domain. Secondly, the NSCT coefficient histograms of the original image in corresponding subbands are adaptively mapped to those of the reference image via histogram matching after threshold denoising. Finally, the enhanced image is reconstructed fl＇om the modified coefficients via inverse NSCT. Experimental results demonstrate that the proposed adaptive algorithm effectively improves subtle features while suppressing noise compared with existing algorithms.

关键词： 100.0100 Image processing 100.2000 Digital image processing 100.2980 Image enhancement 350.6980 Transforms

Pan-sharpening of multi-spectral images using over-complete rational-dilation wavelet transform

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Chinese Optics Letters 2012年第B06期10卷 88-92页

作者：王海江杨勤科王春梅郭伟玲 Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources Xianyang 712100 China Department of Urban and Resource Sciences Northwest University Xi'an 710069 China

A rational-dilation wavelet transform （RWT） based pan-sharpening method for multi-spectral （MS） images of various oscillatory nature is proposed. The previous multi-scale transforms, such as wavelets, curvelets and contourlets, decompose an image into channels with low constant Q-factors, and aren＇t suitable for pan- sharpening images with different behavior in frequency domain. The RWT as an over-complete scheme not only increases the sampling in spatial and frequency domain, but also provides a tunable Q-factor approach to be suitable for a given dataset. We studied its multi-scale decomposition scheme and the RWT based pan-sharpening method. The MS image pan-sharpening experiments show that this method using a better suitable parameter set can achieve a promising performance and often outperforms many other widely-used Dan-sharpening methods both in visual aualitv and in term of evaluation indexes.

关键词： 100.0100 Image processing 100.2000 Digital image processing 100.7410 Wavelets

Design and implementation of real-time high definition aerial camera based on ADSP-BF561

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Chinese Optics Letters 2012年第B06期10卷 107-110页

作者：邓家军云利军石俊生王坤伍明华 Color & Image Vision Lab. Yunnan Normal University Kunming 650500 China College of Information Yunnan Normal University Kunming 650500 China Huanan Photoelectric (Croup) Co. Ltd of Hunan Changde 415105 China

To meet application requirements of high resolution and high frame rate for the aerial camera, a real-time high definition （HD） aerial camera imaging system is designed and developed. A KAI-01050 charge-coupled device （CCD）, ADSP-BF561, and AD9920A are used in the system. ADSP-BF561 is used to configure registers of AD9920A for generating the timing-driven signals to meet CCD parameter needs, and image stitching through ping-pong operation of collected video signals is achieved, then the image is displayed correctly. In the end, the system is developed, 1 M pixels and 60 frame rate are realized, and running results on the system verify effectiveness of the design program.

关键词： 110.0110 Imaging systems 040.1520 CCD, charge-coupled device 040.7290 Video 100.2000 Digital image processing

Automatic splicing algorithm for building super viewing field from disordered image sequence

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Chinese Optics Letters 2012年第B06期10卷 93-96页

作者：陈聪刘贵喜 School of Mechano-Electronic Engineering Xidian University Xi'an 710071 China Chinese Aeronautical Radio Electronics Research Institute Shanghai 200233 China

An effective image splicing algorithm based on phase correlation and speeded-UP robust features （SURF） operator is proposed which can sort the disordered sequence and stitch them into a super viewing field image without any human intervention. Phase correlation in frequency domain is used for images sorting and region of interest （ROI） estimation, and guiding features extracting and matching in spatial domain by SURF operator and bidirectional best bin first （BBF） strategy. The experimental results demonstrate that this algorithm not only can deal with the input images with translation, rotation and scale changes, but also outperforms the pre-existing methods on the aspect of repeatability, efficiency and accuracy.

关键词： 100.2000 Digital image processing 110.3010 Image reconstruction techniques 110.6980 Transforms 350.5730 Resolution

Active noise thin-plate spline smoothing method for full-field strain measurement by digital image correlation

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Chinese Optics Letters 2012年第B06期10卷 114-116页

作者：赵加清曾攀雷丽萍杜泓飞何文斌 Key Laboratory for Advanced Materials Processing Technology of MOE Department of Mechanical Engineering Tsinghua University Beijing 100084 China

Digital image correlation has become an important and effective non-contact optical full-field strain mea- surement technique. The strain field obtained directly by image correlation algorithm is full of noise. In this letter, we explore a novel way of actively adding small amount of Gaussian random noise to original displacement field, subsequently utilizing the well-known thin-plate spline smoothing （TPSS） technique to smooth the noised displacement field, and finally differentiating smoothed displacement field to get reliable strain field. The resultant method, named as active noise thin-plate spline smoothing （ANTPSS）, outperforms the conventional TPSS and spline least-squares approximation. Moreover, ANTPSS success- fully smooths the displacement filed obtained from three-point bending experiment of foam block and generates a reliable inhomogeneous strain field.

关键词： 120.6650 Surface measurements, figure 100.2000 Digital image processing 110.6150 Speckle imaging