A survey on image and video stitching

Image/video stitching is a technology for solving the field of view(FOV)limitation of images/videos.It stitches multiple overlapping images/videos to generate a wide-FOV image/video,and has been used in various fields such as sports broadcasting,video surveillance,street view,and entertainment.This survey reviews image/video stitching algorithms,with a particular focus on those developed in recent years.Image stitching first calculates the corresponding relationships between multiple overlapping images,deforms and aligns the matched images,and then blends the aligned images to generate a wide-FOV image.A seamless method is always adopted to eliminate such potential flaws as ghosting and blurring caused by parallax or objects moving across the overlapping regions.Video stitching is the further extension of image stitching.It usually stitches selected frames of original videos to generate a stitching template by performing image stitching algorithms,and the subsequent frames can then be stitched according to the template.Video stitching is more complicated with moving objects or violent camera movement,because these factors introduce jitter,shakiness,ghosting,and blurring.Foreground detection technique is usually combined into stitching to eliminate ghosting and blurring,while video stabilization algorithms are adopted to solve the jitter and shakiness.This paper further discusses panoramic stitching as a special-extension of image/video stitching.Panoramic stitching is currently the most widely used application in stitching.This survey reviews the latest image/video stitching methods,and introduces the fundamental principles/advantages/weaknesses of image/video stitching algorithms.Image/video stitching faces long-term challenges such as wide baseline,large parallax,and low-texture problem in the overlapping region.New technologies may present new opportunities to address these issues,such as deep learning-based semantic correspondence,and 3D image stitching.Finally,this survey discusses the challenges of image/video stitching and proposes potential solutions.

Research on Stitching Algorithm Based on Tree Branch Image

Branch identification technology is a key technology to achieve automated pruning of fruit tree branches, and one of its technical bottlenecks lies in the stitching of branch images. To this end, we propose a set of branch image stitching technology algorithms. The algorithm is based on the grey-scale prime centroid method to determine the detection feature points, and uses the coordinate transformation matrix H of the corresponding points of the image to carry out the image geometric transformation, and realises the feature matching through sample comparison and classification methods. The experimental results show that the matched point images are more correct and less time-consuming.

A PREDICTIVE APPROACH TO THE IN-PLANE MECHANICAL PROPERTIES OF STITCHED COMPOSITE LAMINATES

This contribution attempts to model the alteration of the in-plane elastic properties in laminates caused by stitching, and to predict the in-plane effective tensile strength of the stitched composite laminates. The distortion of in-plane fibers is considered to be the main cause that affects the in-plane mechanical properties. A fiber distortion model is proposed to characterize the fiber misalignment and the fiber content concentration due to stitching. The undistorted region, the fiber distortion region, the resin-rich pocket and the through-thickness reinforcement section are taken into account. The fiber misalignment and inhomogeneous fiber content due to stitching have been formulated by introducing two parameters, the distortion width and maximum misalignment. It has been found that the ply stress concentration in stitched laminates is influenced by the two concurrent factors, the stitch hole and inhomogeneous fiber content. The stitch hole brings about the stress concentration whereas the higher fiber content at the local region induced by stitching restrains the local deformation of the composite. The model is used to predict the tensile strength of the [0/45/0/-45/90/45/0/-45]58 T300/QY9512 composite laminate stitched by Kevlar 29 yarn with different stitching configurations, showing an acceptable agreement with experimental data.

Stitch Fix 数据驱动的服装零售公司

Stitch Fix运用大数据技术改造甚至颠覆了传统的服装零售业,其数据驱动的新零售模式,对我国正在推动的大数据战略下的商业模式创新具有借鉴意义。2011年成立于美国旧金山的Stitch Fix是一家服装零售公司,同时也是一家大数据科技公司。除了提供自有服饰品牌外,Stitch Fix还提供700多个流行服装品牌,其商业模式充分展现了线上线下结合并以数据为驱动力的新零售业态。

A morphology-stitching method to improve Landsat SLC-off images with stripes

Stripes are artifacts in satellite images caused by various factors such as hardware defects. In some cases, these artifacts are introduced by some mitigating algorithms like Landsat SLC-off （Scan Line Corrector） gap-filling methods of LLHM （Local Linear Histogram Matching） and AWLHM （Adaptive Window Linear Histogram Matching）, which leave stripes as a byproduct. To improve Landsat SLC-off images with stripes,we propose an algorithm involving some hypothetical stripe-crossing stitch lines using the mean pixel value of the stitch lines.

One-stitch anastomosis through the skin with bicanalicular intubation:a modified approach for repair of bicanalicular laceration

AIM:To evaluate the efficacy and safety of one-stitch anastomosis through the skin with bicanalicular silicone tube intubation in repairing of bicanalicular laceration.METHODS:The clinical data of 15 consecutive patients with both superior and inferior canalicular laceration in one eye who underwent surgical repair using one-stitch anastomosis through the skin and bicanalicular stent were retrospective studied.All the operations were performed under surgical microscope,5-0 silk sutures were used and were with bicanalicular silicone tube(diameter was 8mm) intubation,for one lacerated canaliculi one-stitch anastomosis through the skin.The stents were left in place for 3 months postoperatively and then removed.The follow-up period was 3-36 months(average 14 months). RESULTS:In 15 patients,13 patients were cured entirely,1 patient was meliorated,1 patient with no effects.All patients had got good recovery of eyelid laceration with no traumatic deformity in eyelid and canthus.Complication was seen in one case,for not followed the doctor’s guidance to come back to hospital to had the suture removed on the 7thday after operation,when he came at the 15thday,the inferior canalicular wall and eyelid skin were corroded by the suture caused 2mm wound,and the inside silicone tube was exposed,a promptly repair with 10-0 nylon suture was done,the wound healed in a week.There were no early tube protrusions and punctal slits in the patients.CONCLUSION:One-stitch anastomosis through the skin with bicanalicular silicone tube intubation is a good method in repair of bicanalicular laceration in one eye,the cut ends can be anastomosed directly,and with excellent cosmetic results,it is acceptable for the patients.For there is no suture remained in the wound permanently,so there is no suture-related granuloma which may cause obstruction or stenosis of canaliculi.It is simple,economical,effective and safe.

Underwater Terrain Image Stitching Based on Spatial Gradient Feature Block

At present,underwater terrain images are all strip-shaped small fragment images preprocessed by the side-scan sonar imaging system.However,the processed underwater terrain images have inconspicuous and few feature points.In order to better realize the stitching of underwater terrain images and solve the problems of slow traditional image stitching speed,we proposed an improved algorithm for underwater terrain image stitching based on spatial gradient feature block.First,the spatial gradient fuzzy C-Means algorithm is used to divide the underwater terrain image into feature blocks with the fusion of spatial gradient information.The accelerated-KAZE(AKAZE)algorithm is used to combine the feature block information to match the reference image and the target image.Then,the random sample consensus(RANSAC)is applied to optimize the matching results.Finally,image fusion is performed with the global homography and the optimal seam-line method to improve the accuracy of image overlay fusion.The experimental results show that the proposed method in this paper effectively divides images into feature blocks by combining spatial information and gradient information,which not only solves the problem of stitching failure of underwater terrain images due to unobvious features,and further reduces the sensitivity to noise,but also effectively reduces the iterative calculation in the feature point matching process of the traditional method,and improves the stitching speed.Ghosting and shape warping are significantly eliminated by re-optimizing the overlap of the image.

Removal of laparoscopic cerclage stitches via laparotomy and rivanol-induced labour: A case report and literature review

BACKGROUND Laparoscopic cervical cerclage is performed for patients with abnormal cervical anatomy and/or transvaginal cervical cerclage failure.However,the method of removing the stitches to allow labour induction remains controversial.According to published literature,stitches are removed through laparoscopic or transvaginal methods.Herein,we report,for the first time,a case of a patient who had undergone laparoscopic cerclage,and then underwent removal of stitches by laparotomy and labour induction in the third trimester of pregnancy.CASE SUMMARY A patient who underwent laparoscopic cervical cerclage due to cervical insufficiency became pregnant naturally following the operation.At 31 wk of pregnancy,severe foetal malformations were found.To successfully induce labour,cerclage stitches were removed via laparotomy,and rivanol was injected directly into the uterus.Following successful induction of labour,the patient delivered a dead foetus.CONCLUSION This report provides a reliable scheme of removing cerclage stitches for patients who have undergone laparoscopic cerclage but experience severe foetal malformations.

基于Multi-stage的double stitch工艺在铜线焊中的应用

作为引线键合工艺中传统的焊接材料,金线在稳定性、导电性及价格等方面存在诸多局限,使得铜线焊技术在IC封装领域得到越来越广泛的应用。同时,由于铜线易氧化、硬度高,焊接能力较低,特别是二焊点容易出现拉力不够、开裂等缺陷,使得铜线焊的应用受到限制。针对传统工艺流程,提出Multi-stage方法,并在此基础上实现二焊点的double stitch工艺方法,通过试验证明该方法能够有效提高二焊点拉力,增强焊接强度。

Efficient Image Stitching in the Presence of Dynamic Objects and Structure Misalignment

This paper presents a new method for simultaneously eliminating visual artifacts caused by moving objects and structure misalignment in image stitching. Given that the input images are roughly aligned, our approach is implemented in two stages. In the first stage, we discover motions between input images, and then extract their corresponding regions through a multi-seed based region growing algorithm. In the second stage, with prior information provided by the extracted regions, we perform a graph cut optimization in gradient-domain to determine which pixels to use from each image to achieve seamless stitching. Our method is simple to implement and effective. The experimental results illustrate that the proposed approach can produce comparable or superior results in comparison with state-of-the-art methods.

DYNAMICS OF THE LOOPER DRIVE MECHANISM ON A BLIND STITCHING MACHINE

The looper drive mechanism is a main moving part in the blind stitching machine, which is aspatial 5 bar RRRSR linkage. In this paper, a dynamic analysis of the looper drive mechanism is made by means of the ma-trix method. Two methods are adopted in the calculation of the shaking force and shaking moment, one isdone by the constraint reaction of the flame-connected kinematic parts; the other is the inertialforces of all moving links.

Mechanical Behavior and Microstructure Characterization of 3D Stitched Quartz Fibers-reinforced Silica Composites

The mechanical properties of silica material in the monolithic form are ;far from acceptable levels. In this paper, 3D stitched quartz preform was used for the fiber reinforcement, and quartz fibers- reinforced silica composites were prepared by the silica sol-infiltration-sintering method. The density of the composite was up to 1.71 g/cm3 after 10 infiltration-sintering cycles. The flexural strength and the in-plane shear strength were 61.7 MPa and 20.3 MPa, respectively. The flexural stress-deflection curve exhibited mostly nonlinear behavior, which was different from that of monolithic ceramics. Because of the existence of the fiber in Z axis direction, shearing property between the different layers of 3D stitched composites were greatly enhanced. Toughness effect of the 3D stitched quartz preform was conspicuous. The as-fabricated composites showed non-catastronhic failure behavior resulting from weak fiber/matrix interface.

Low-Velocity Impact Response of Stitched Multi-layer Foam Sandwich Composites

Low-velocity impact damage known as“imperceptible”damage usually destroys the structural integrity of the material and seriously affects the service life of the materials.To improve the low-velocity impact resistance of foam sandwich composites,an innovative concept of a stitched multi-layer sandwich structure by organically combining the discrete splitting of foam layer with full thickness stitching was proposed,and its low-velocity impact resistance obtained through drop-hammer impact tests was explored.The results showed that the multi-layer foam sandwich structure acted as a stress disperser and reduced the irreversible impact damage.The depth and area of low-velocity impact damage of multi-layer foam sandwich composites gradually decreased with increasing the number of the layers.The stitched structure would improve the integrity of the foam sandwich composites and inhibit the propagation of cracks.The maximum impact load of the stitched foam sandwich composite increased by approximately 5% compared with that of the non-stitched material.In addition,the low-velocity impact damage depth,damage area and absorbed energy of the stitched three-layer foam sandwich composite were reduced by 37.7%,34.6% and 20.7%,respectively,compared with those of the non-stitched single-layer sandwich material.

Stitched Ground Planes for Textile Antenna Application: An Experimental Study

This paper presents an application of stitched ground plane for microstrip patch antenna design. In this work Matlab interface to computer embroidery techniques were used to implement the felt and denim substrates on microstrip patch antenna. These antennas were simulated using a commercial full 3D electromagnetic CST Microwave Studio 2019. A method to optimize the stitch patterns with conductive thread for antenna ground plane for 2.45 GHz industrial, scientific, and medical (ISM) band and 5 GHz wearable wireless local area networks (WLAN) frequencies was achieved. Rigid and flexible wearable antennas (microstrip patch antennas) were fabricated using the stitched ground plane. The electrical resistance was reduced between the meshes during the stitching design process. Results in terms of bandwidth, radiation patterns and reflection coefficients (S11) are presented.

Novel Stitched Ground Plane Optimizations for Microstrip Patch Antennas at Wi-Fi and WiMAX Applications

This work explores the optimal mesh structure, stitch density and production technique of stitched ground plane for microstrip patch antenna. Meshed ground plane was used as a generic problem. A stitched ground plane is pro-posed and designed using Matlab interface to computer embroidery. Using the meshed or stitched ground plane as a case study, the resistance between meshes was analysed and measured. The equivalent resistance between nodes is a function of their distance apart. A finite resistive grid was simulated and compared to measured sets of data. A microstrip patch antenna with stitched ground shows comparable performance to the conventional etched ground of the size in terms of bandwidth. The stitched ground plane has a higher band-width than the etched copper ground plane because of the increased thickness of the substrate. Thus, it can be concluded that the use of the interface method shows the possibilities of controlling the stitch density and distances between mesh nodes. The interface increases the stitching density and reduces the elec-trical resistance between mesh nodes making the antennas flexible and weara-ble. The functionality of these antenna samples has been tested and validated using microstrip patch ground at 2.45 GHz and 5 GHz. Measurement results on the proposed stitched ground planes were compared with the theory of infinite resistive network that shows good agreement.

Automatic Damage Detection and Monitoring of a Stitch Laminate System Using a Fiber Bragg Grating Strain Sensor

There are numerous aspects and questions related to the use of composite materials for primary structures in aircraft where the structural integrity is the most important factor. This is especially true if the main concerns are that the material should have good reliability and durability for the primary structural application. Composite laminates are highly sensitive to out-of-plane failure due to their low inter laminar fracture toughness. An alternate method to increase the damage resistance is through three-dimensional fibrous reinforcement such as through-the-thickness stitching with a single fiber as the thread. Recent studies have shown that the stitching of standard laminates can enhance damage tolerance to levels obtainable with toughened resin systems. However, for next-generation aircraft, material improvement alone is not enough to assure or increase the safety and reliability of the structure. Continuous damage monitoring during operation will become an important issue in aircraft safety. Embed ding fiber Bragg grating (FBG) technology into the composite structure as strain sensors could potentially solve the above problem because the FBG can be used to detect and characterize the damage before it reaches a critical stage. The model used to represent this problem is a 6 × 6 Vectran stitched carbon/ epoxy laminate under tension loading, and the real-time monitoring using the FBG strain sensors is combined with acoustic emissions that were conducted during the test. A numerical laminate theory using a rebar element and first-ply failure criterion is performed to determine the preferred area on the specimen for the placement of the FBG before manufacturing and testing. Experiments are presented to determine the damage growth that was quantified with an ultrasonic (water immersion) c-scan. In this research, the FBG successfully detected and characterized the damage in the carbon/epoxy stitch laminate caused in tension loading cases. The FBG is enhanced with acoustic emission data and can quantitatively predict the damage growth.

Controllable Crack Propagation in Off-Axis Crushing of Stitched Composite Absorbers

Crack growth resistance plays a different role in crashworthiness analysis since the progressive energy absorption is based on controllable fracture mechanisms. In this regard, the present paper studies the efficient crack growth resistance in off-axis crushing of composite tubular structures by implementing natural fiber yarns. One of the through-to-thickness reinforcement methods known as stitching has been chosen to influence the axial and off-axis crushing process. Improving the crack growth resistance and appropriate fiber breakage at different stages of crushing process can significantly improve the resistance force and consequently the energy absorption capability of composite absorbers in axial and off-axis crushing. This analysis will be applied to non-stitched and stitched CFRP composite boxes which showed brittle fracture and transverse shearing crushing modes under off-axis loading of 10 degrees. The analytical methods are also implemented to analysze the effect of various failure mechanisms such as bending, friction, bundle fracture, and interlaminar crack growth for the observed crushing modes. The proposed model is able to predict the crushing load and crush force efficiency in close agreement from experimental studies.

Influence of Lycra Content and Stitch Length on the Dimensional and Physical Characteristics of Lycra Back Plaited Cotton (LBPC) Single Jersey Fabrics

The physical and dimensional characteristics, i.e. course and wale spacing, stitch density, tightness factor, diameter, porosity, dimensional stability and bursting strength of single jersey knitted items containing lycra yarn with the variations in stitch length and lycra content have been examined and a detail investigation on the lycra filament has been discussed in this study. Six different samples were knitted with identical cotton and lycra yarn but different in lycra contents and stitch length. After conditioning in a controlled environment, all the samples were tested as per the established methods. After analyzing the test results, noticeable effects of variations in stitch length and lycra content on physical and dimensional characteristics of single jersey knitted fabric has been found. As smaller the stitch length and as greater the lycra content, the dimensional stability and bursting strength are better;on the other hand, the air permeability is lower.

Perceptual quality assessment of panoramic stitched contents for immersive applications:a prospective survey

The recent advancements in the field of Virtual Reality(VR)and Augmented Reality(AR)have a substantial impact on modern day technology by digitizing each and everything related to human life and open the doors to the next generation Software Technology(Soft Tech).VR and AR technology provide astonishing immersive contents with the help of high quality stitched panoramic contents and 360°imagery that widely used in the education,gaming,entertainment,and production sector.The immersive quality of VR and AR contents are greatly dependent on the perceptual quality of panoramic or 360°images,in fact a minor visual distortion can significantly degrade the overall quality.Thus,to ensure the quality of constructed panoramic contents for VR and AR applications,numerous Stitched Image Quality Assessment(SIQA)methods have been proposed to assess the quality of panoramic contents before using in VR and AR.In this survey,we provide a detailed overview of the SIQA literature and exclusively focus on objective SIQA methods presented till date.For better understanding,the objective SIQA methods are classified into two classes namely Full-Reference SIQA and No-Reference SIQA approaches.Each class is further categorized into traditional and deep learning-based methods and examined their performance for SIQA task.Further,we shortlist the publicly available benchmark SIQA datasets and evaluation metrices used for quality assessment of panoramic contents.In last,we highlight the current challenges in this area based on the existing SIQA methods and suggest future research directions that need to be target for further improvement in SIQA domain.

Diffusion Analysis of Message Expansion in STITCH-256

Cryptographic hash functions are built up from individual components, namely pre-processing, step transformation, and final processing. Some of the hash functions, such as SHA-256 and STITCH-256, employ non-linear message expansion in their pre-processing stage. However, STITCH-256 was claimed to produce high diffusion in its message expansion. In a cryptographic algorithm, high diffusion is desirable as it helps prevent an attacker finding collision-producing differences, which would allow one to find collisions of the whole function without resorting to a brute force search. In this paper, we analyzed the diffusion property of message expansion of STITCH-256 by observing the effect of a single bit difference over the output bits, and compare the result with that of SHA-256. We repeated the same procedure in 3 experiments of different round. The results from the experiments showed that the minimal weight in the message expansion of STITCH-256 is very much lower than that in the message expansion of SHA-256, i.e. message expansion of STITCH-256 produce high diffusion. Significantly, we showed that the probability to construct differential characteristic in the message expansion of STITCH-256 is reduced.