Novel Frame Shift and Integral Technique for Enhancing Low-Light-Level Moving Images

A novel frame shift and integral technique for the enhancement of low light level moving image sequence is introduced. According to the technique, motion parameters of target are measured by algorithm based on difference processing. To obtain spatial relativity, images are shifted according to the motion parameters. As a result, the processing of integral and average can be applied to images that have been shifted. The technique of frame shift and integral that includes the algorithm of motion parameter determination is discussed, experiments with low light level moving image sequences are also described. The experiment results show the effectiveness and the robustness of the parameter determination algorithm, and the improvement in the signal-to-noise ratio （SNR） of low light level moving images.

The Moving Image 16, no. 1—Special Issue： Early Cinema and the Archives

This paper would investigate the Moving Image Archive at the Cinema Museum in Tehran to highlight the importance of new media in Iran after the 1930s and the changes that were brought about by the birth of cinema in the existing geopolitical conditions. It would look very closely at the first silent film made in Iran titled Haji Agha, the Cinema Actor （1933） by Ovanes Ohanian. While reflecting on the socio-political relation of the film to its era, this paper would also bring to attention the process of filmmaking and screening in 1930s Iran--the production and restoration of footage, posters and publicity for the film, and the screening venue. The cinema in question used to be called TamashaKhaneh when it was simply a projection room in Tehran where people would keenly take their seats to view the same film over and over again in some cases. The author would investigate the advent of cinema as a foreign concept in Iranian life and try to reflect upon the way in which it has been gradually adopted as a national treasure over the years. Haji Agha, the Cinema Actor is one of the most important reflections of the social transition that has occurred in Iranian history. Here, through the hundred-minute black and white footage, Ohanian depicts the tense political climate following the coup of Mossadegh, as well as the ban on traditional clothing during the last monarchy of Iran; at the same time, the film represents tradition and modernity as two supposedly opposite stances that, in fact, complemented each other in this era. The title combines Haji Agha, a religious man who has visited mecca, with the English words the Cinema Actor, to further express the complementary relation between old and new. Ohanian very professionally depicts the role of family as a core part of the religious boundaries for men and women that unfold throughout the film due to their encounter with cinema and filmmaking. He uses issues like sex and taboo to push the boundaries and map a certain cultural modernity within Iranian society.

Authentication Method Using a Discrete Wavelet Transform for a Digital Moving Image

Recently, several digital watermarking techniques have been proposed for hiding data in the frequency domain of moving image files to protect their copyrights. However, in order to detect the water marking sufficiently after heavy compression, it is necessary to insert the watermarking with strong intensity into a moving image, and this results in visible deterioration of the moving image. We previously proposed an authentication method using a discrete wavelet transform for a digital static image file. In contrast to digital watermarking, no additional information is inserted into the original static image in the previously proposed method, and the image is authenticated by features extracted by the wavelet transform and characteristic coding. In the present study, we developed an authentication method for a moving image by using the previously proposed method for astatic image and a newly proposed method for selecting several frames in the moving image. No additional information is inserted into the original moving image by the newly proposed method or into the original static image by the previously proposed method. The experimental results show that the proposed method has a high tolerance of authentication to both compressions and vicious attacks.

Application of Depth Learning Algorithm in Automatic Processing and Analysis of Sports Images

With the rapid development of sports,the number of sports images has increased dramatically.Intelligent and automatic processing and analysis of moving images are significant,which can not only facilitate users to quickly search and access moving images but also facilitate staff to store and manage moving image data and contribute to the intellectual development of the sports industry.In this paper,a method of table tennis identification and positioning based on a convolutional neural network is proposed,which solves the problem that the identification and positioning method based on color features and contour features is not adaptable in various environments.At the same time,the learning methods and techniques of table tennis detection,positioning,and trajectory prediction are studied.A deep learning framework for recognition learning of rotating flying table tennis is put forward.The mechanism and methods of positioning,trajectory prediction,and intelligent automatic processing of moving images are studied,and the self-built data sets are trained and verified.

SAR Moving Target Detection and Imaging Based on WVH Transform

Aim To propose a generalized and closed representation of the Wigner Ville Hough transform(WVHT), for the moving target detection and imaging in the design of synthetic aperture radar(SAR). Methods Based on the line integral, the WVH transform was derived by combining the Wigner Ville distribution (WVD) and the Hough transform (HT) together. The new transform was then verified with computer by the simulated SAR echoes. Results and Conclusion The correctness and the validity of the WVH transform were proved by the computer simulation. Compared with the conventional WVD HT method, the new approach based on the WVHT can simplify the processing procedure, it can translate the chirp echoes of multi targets of SAR from the time domain into the parameter space directly, while suppressing the cross terms of WVD and estimating the motion coefficients for the final imaging. It is obvious that the WVH transform can be also used in other cases for the chirp signal detection.

STUDY ON THE SIGNATURE OF GROUND MOVING TARGET FOR AIRBORNE SQUINT SAR IMAGING

Compared with the side-looking Synthetic Aperture Radar (SAR), the flexible beampointing of squint SAR makes great application value. This paper derives the image signature of the ground moving target after the processing of Range-Doppler (RD) algorithm, the SAR signatures of ground moving targets are analyzed, including the geometry correction, the offsets and defocusing in both range and azimuth direction. Finally, computer simulation results validate its effectiveness. The research results are especially significant for moving targets detection and parameters estimation in squint mode SAR.

Influence on Visibility Due to Differences of Guide Wire Movement―Visual &Physical Evaluations

The visibility of moving images during cardiac catheterization and treatment may be reduced by a number of factors. First, it involves multiple movements that occur simultaneously, such as the movements due to the heart beat and movement of the guide wire used during the treatment. There is also the influence of the X-ray dose on the image quality in the X-ray output. If X-rays are irradiated onto moving objects such as a guide wire moving during treatment of the heart, cardiac catheterization may be displaced to the next image recorded even when an insufficient X-ray dose has been irradiated because the imaged object is moving during the time the X-rays are emitted (pulse width). If the X-ray dose planned to be irradiated to the target is low, there is also the possibility that noise will appear in the image, and the imaged object may be lost in noise and visibility be reduced. For this reason, we conducted basic research into how changes in the speed of rotation of guide wires affect visibility when wires are positioned horizontally and vertically, using a dynamic phantom and recorded X-ray moving images. The purpose of this study is to elucidate whether the deterioration in the visibility is affected by the X-ray dose, the orientation or movement of a guide wire, or caused by other conditions, in order to contribute to improving the visibility in the X-ray moving images. The results showed a lower visual evaluation only in the vertical direction at the more rapid movement here, but this did not result in significant changes in the physical evaluation. This suggests that the structure and characteristics of the human eyes would be involved, as human vision is stronger with lateral movements and weaker with vertical movements due to the arrangement of the human eyes, side by side. Findings from this basic study can be utilized to improve the visibility in the X-ray moving images by paying attention to the observation environment of the observer of the X-ray moving images. In addition, the findings of this study can also be used to determine protocols for improving visibility in X-ray moving images, such as adjusting the X-ray dose in an X-ray device when further improvement is required. Therefore, this study was able to provide suggestions to contribute to the development of improved visibility of X-ray moving images.

Development of PC-based Electronic Teaching and Learning Materials for De- scriptive Geometry

Descriptive geometry is very important and recognized as a basic skill and knowledge for mechanical engineering student. In this study, PC-based electronic teaching/learning materials for descriptive geometry are created using Flash, which is a typical animation creator. Furthermore, several axonometric representations, created by 3D-CAD, SolidWorks, for 3D objects are auxiliary materials to promote understanding of descriptive geometry. The axonometric representations in 3D-CAD are also dynamic, in other words, a viewpoint can be moved free. The movement of 3D model in a PC monitor can be recorded using a normal function of SolidWorks and replayed by typical animation software. The developed materials are excellent at accuracy of drawing, repeatability of self-study and visual attraction in comparison to oral presentation using still image and inaccurate drawing on a textbook or blackboard in a classroom. Actually, questionnaire survey results present favorable impressions from student-users, although they point out the further improvement in the replaying speed. The replaying speed can be controlled easily by using a normal function of Flash. In addition, usual playback software for animation has functions of pause and replay on demand and, thus, it is not contro-versial.

IMAGING AND MTI PROCESSING BASED ON DUAL-FREQUENCIES DUAL-APERTURES SPACEBORNE SAR

Based on dual-frequencies dual-apertures spaceborne SAR （Synthetic Aperture Radar）, a new SAR system with four receiving channels and two operation modes is presented in this paper, SAR imaging and Moving Target Indication （MTI） are studied in this system. High resolution imaging with wide swath is implemented by the Mode Ⅰ, and MTI is completed by the Mode Ⅱ. High azimuth resolution is achieved by the Displaced Phase Center （DPC） multibeam technique. And the Coherent Accumulation （CA） method, which combines dual channels data of different carrier frequency, is used to enhance the range resolution. For the data of different carrier frequency, the two aperture interferometric processing is executed to implement clutter cancellation, respectively. And the couple of clutter suppressed data are employed to implement Dual Carrier Frequency Conjugate Processing （DCFCP）, then both slow and fast moving targets detection can be completed, followed by moving target imaging. The simulation results show the validity of the signal processing method of this new SAR system.

Liutex identification on hairpin vortex structures in a channel based on msfle and moving-PIV

The spatiotemporal evolution of hairpin vortex structures in a fully developed turbulent boundary layer is investigated qualitatively and quantitatively by using two image methods.In this paper,the moving single-frame and long-exposure(MSFLE)image method is used to intuitively track the evolution process of a hairpin vortex,while the moving particle image velocimetry(moving-PIV)method is applied for obtaining a moving velocity field for quantitative analysis.According to the structural characteristics of the hairpin vortex,an inclined light sheet with an appropriate inclination of 53°is arranged to capture the complete hairpin vortex structure at Re_(θ)=97–194.In addition,the core size and the rotational strength of a hairpin vortex are further defined and quantified by the Liutex vector method.The evolution process of a complete hairpin vortex structure observed by MSFLE shows that the shear along the normal direction leads to an increasing strength of the hairpin vortex,accompanied by a lifting vortex head and a distance decrease between two vortex legs during the dissipation period.By combining moving-PIV with the Liutex identification,the spatiotemporal evolution of four typical regions of a hairpin vortex projecting into a 53°cross-section is obtained.The results show that the process from the generation to the dissipation of a single hairpin vortex can be well characterized and recorded by the Liutex based on the core size and rotational intensity,and the evolution process is consistent with the MSFLE result.According to the statistics of vortex core size and rotation intensity along time,the evolution of the hairpin vortex necks and legs can be described as a process of enhancement followed by dissipation.For the vortex head,its evolution maintains longer attributed to its far-from-wall position,which consists of an absolute enhancement process(stage 1)with an increasing rotation strength and a constant core size,and an absolute dissipation(stage 2)with a decreasing rotation strength and a constant core size.

Ghost imaging for an axially moving target with an unknown constant speed

The influence of the axial relative motion between the target and the source on ghost imaging(GI) is investigated.Both the analytical and experimental results show that the transverse resolution of GI is reduced as the deviation of the target’s center position from the optical axis or the axial motion range increases. To overcome the motion blur,we propose a deblurring method based on speckle-resizing and speed retrieval, and we experimentally validate its effectiveness for an axially moving target with an unknown constant speed. The results demonstrated here will be very useful to forward-looking GI remote sensing.

Depth extraction method with high accuracy in integral imaging based on moving array lenslet technique

In order to improve depth extraction accuracy, a method using moving array lenslet technique(MALT) in pickup stage is proposed, which can decrease the depth interval caused by pixelation. In this method, the lenslet array is moved along the horizontal and vertical directions simultaneously for N times in a pitch to get N sets of elemental images. Computational integral imaging reconstruction method for MALT is taken to obtain the slice images of the 3 D scene, and the sum modulus(SMD) blur metric is taken on these slice images to achieve the depth information of the 3 D scene. Simulation and optical experiments are carried out to verify the feasibility of this method.

Experimental study on dynamic mechanism of vortex evolution in a turbulent boundary layer of low Reynolds number

The dynamic mechanism of the vortex generation and evolution process in a fully developed turbulent boundary layer with Reθ=97-194 is experimentally investigated.In this study,a moving single-frame and long-exposure(MSFLE)imaging method and a moving particle image velocimetry/particle tracing velocimetry(M-PIV/PTV)are designed and implemented for measuring the temporal and spatial evolution of vortex cores in both qualitative and quantitative ways,respectively.On the other hand,the Liutex vector,which is a new mathematical definition and identification of the vortex core proposed by Liu’s group,is first applied in the experiment for the structural visualization and quantitative analysis of the local fluid rotation.The results show that an intuitional process of vortex evolution can be clearly observed by tracking the vortex using MSFLE and verify that the roll-up of the shear layer induced by shear instability is the origin of vortex formation in turbulence.Furthermore,a quantitative investigation in terms of the critical vortex core boundary(size)and its accurate rotation strength is carried out based on the Liutex vector field analysis by M-PIV/PTV.According to statistics of the relation between vortex core size and the rotation strength during the whole process,the physical mechanism of vortex generation and evolution in a turbulent boundary layer of low Reynolds number can be summarized as a four-dominant-state course consisting of the“synchronous linear segment(SL)-absolute enhancement segment(AE)-absolute diffusion segment(AD)-skewing dissipation segment(SD)”.