Optics and Precision Engineering 

About: Optics and Precision Engineering is an academic journal published by Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences. The journal publishes majorly in the area(s): Laser & Pixel. It has an ISSN identifier of 1004-924X. Over the lifetime, 3450 publications have been published receiving 10657 citations. The journal is also known as: Optics and Precision Engineering.

Multifocus image fusion method of sharp frequency localized Contourlet transform domain based on sum-modified-Laplacian

Abstract: In order to suppress the pseudo-Gibbs phenomena around singularities of fused images and to reduce significant amounts of aliasing components located far away from desired supports when the original Contourlet is employed in the image fusion,a multifocus image fusion method in Sharp Frequency Localized Contourlet Transform(SFLCT) domain based on a sum-modified-Laplacian is proposed.The SFLCT,instead of the original Contourlet,is utilized as the multiscale transform to decompose the original multifocus images into subbands.Then,typical measurements for the multifocus image fusion in a spatial domain are introduced to the Contourlet domain and Sum-modified-Laplacian(SML),and the criterion to distinguish SFLCT coefficients from the clear parts or from blurry parts of images are employed in SFCLT subbands to select the SFLCT transform coefficients.Finally,the inverse SFLCT is used to reconstruct fused images.Moreover,a cycle spinning method is applied to compensate for the lack of translation invariance property and to suppress the pseudo-Gibbs phenomena of fused images.Using the proposed fusion method,experimental results demonstrate that the mutual information has improved by 5.87% and transferred edge information QAB/F has improved by 2.70% as compared with those of the cycle spinning wavelet method,and has improved by 1.77% and 1.29% as compared with those of the cycle spinning Contourlet method.Meanwhile,the proposed fusion method has advantages of good visual effect over the block-based spatial SML method and shift-invariant wavelet method.

Solution of small sample size problem in face recognition using Gabor wavelet transform

Abstract: A novel algorithm for solving the small sample size problem in face recognition is proposed.The size of each face sample is increased greatly and the small sample size problem is resolved by regarding every Gabor wavelet transformed output image as an independent sample.A special nearest neighbor classifier using whitened cosine distance is designed for the classification of face feature vector groups.The experiments comparing the prosposed approach with the direct PCA method in FERET face database show that the average correct face recognition rate of the proposed algorithm can reach 97%,which is superior to the direct PCA method.

Monocular vision system for distance measurement based on feature points

Abstract: To alleviate the effect of matching of corresponding feature points and extraction error of single feature point,a method by using a single camera as monocular measurement is presented based on image processing.Firstly,this paper sets up the mapping relationship between image point and target point,and establishes pinhole imaging model.Secondly,it describes the mapping relationship between object area and image area of object by using image analysis,and establishes the model of distance measurement in optical direction.Then,the principle of distance measurement between optical center and feature point is proposed after image processing and feature point extracting are carried out.At last,the paper starts out verification experiments and analyzes the cause that error increases with further distance.After analyzing the data of experiment,the conclusion that error is related with the optical axis deviation is made.Sequentially,with the maximum relative error 1.68% of revised data,there is a remarkable improvement which proves the feasibility and the effectiveness of the proposed principle.

Attitude solution for strapdown inertial navigation system based on quaternion algorithm

Abstract: The attitude solution for carrier is one of the key technologies for precision navigation of Strapdown Inertial Navigation System(SINS).In this paper,the strongpoints and defects of Euler algorithm, direction cosine algorithm and quaternion algorithm were analyzed.Then,the carrier attitude was computed separately according to quaternion algorithm and direct cosine algorithm,and the comparative deviation was obtained by contrasting these two solution deviation with theory results.These comparsons prove the validity of quaternion algorithm and conclude that increasing sampling frequency and adopting high-level compute algorithm can lower compute deviation.Digital simulation and experiment results show that the carrier attitude solution relative deviation is 10-10% with numerical theory and 10-3% with test experiment results,the compute time is 36 μs.The proposed attitude solution method can satisfy the real-time demand,and can offer a useful reference for strapdown inertial navigation technology applied in engineering.