Mobile Handheld Research Articles

Handheld Retinal Oximetry in Healthy Young Adults.

PurposeThe objective of this study was to measure the relative retinal oxygen saturation with a prototype, mobile handheld oximeter in upright and supine position and to compare these measurements to the gold standard Oxymap T1 retinal oximeter in upright position. A handheld oximeter is needed for measurements of infants with retinopathy of prematurity as well as acutely injured and bedridden adults.MethodsHealthy volunteers (age 18–35) were recruited at the Leiden University Medical Center. Retinal images were acquired with the handheld oximeter and the Oxymap T1. Both cameras are dual-wavelength oximeters and acquire images with wavelengths of 570 and 600 nm. Retinal oxygen saturation values were determined for both the handheld camera and the Oxymap T1.ResultsTwenty-one subjects (age 25 ± 2 years) were included. In upright position, the oxygen saturation for the arterioles was 92.2% to 4.9% vs. 95.5% ± 4.2% and for the venules 57.9% ± 10.2% vs. 57.7% ± 6.4% for the handheld camera and Oxymap T1, respectively. The oxygen saturation was higher in the arterioles than the venules for both cameras (P < 0.05). In supine position, measured with the handheld oximeter, the oxygen saturation in the arterioles was 92.3% ± 5.8% and 59.2% ± 6.1% in the venules.ConclusionsPerformance of the prototype, mobile handheld oximeter Corimap camera compares well with the Oxymap T1, with a slightly larger standard deviation in oxygen saturation measurements, both in upright and supine patients.Translation RelevanceTo date, to our knowledge, no oximeters are available for handheld use and for measurement in supine position in infants and bedridden adults. Here we tested such an oximeter and show that its performance compares well with that of the gold standard Oxymap T1 in healthy adults.

Accurate Model-Based Point of Gaze Estimation on Mobile Devices.

The most accurate remote Point of Gaze (PoG) estimation methods that allow free head movements use infrared light sources and cameras together with gaze estimation models. Current gaze estimation models were developed for desktop eye-tracking systems and assume that the relative roll between the system and the subjects’ eyes (the ’R-Roll’) is roughly constant during use. This assumption is not true for hand-held mobile-device-based eye-tracking systems. We present an analysis that shows the accuracy of estimating the PoG on screens of hand-held mobile devices depends on the magnitude of the R-Roll angle and the angular offset between the visual and optical axes of the individual viewer. We also describe a new method to determine the PoG which compensates for the effects of R-Roll on the accuracy of the POG. Experimental results on a prototype infrared smartphone show that for an R-Roll angle of , the new method achieves accuracy of approximately , while a gaze estimation method that assumes that the R-Roll angle remains constant achieves an accuracy of . The manner in which the experimental PoG estimation errors increase with the increase in the R-Roll angle was consistent with the analysis. The method presented in this paper can improve significantly the performance of eye-tracking systems on hand-held mobile-devices.

Light interception modelling using unstructured LiDAR data in avocado orchards

In commercial fruit farming, managing the light distribution through canopies is important because the amount and distribution of solar energy that is harvested by each tree impacts the production of fruit quantity and quality. It is therefore an important characteristic to measure and ultimately to control with pruning. We present a solar-geometric model to estimate light interception in individual avocado (Persea americana Mill.) trees, that is designed to scale to whole-orchard scanning, ultimately to inform pruning decisions.The geometry of individual trees was measured using handheld mobile LiDAR and represented by point clouds. A discrete energy distribution model of the hemispherical sky was synthesised using public weather records. The light from each sky node was then ray traced, applying a radiation absorption model where rays pass the point cloud representation of the tree.The model was validated using ceptometer energy measurements at the canopy floor, and model parameters were optimised by analysing the error between modelled and measured energies. The model was shown to perform well qualitatively through visual comparison with tree shadows in photographs, and quantitatively well with R2=0.854, suggesting it is suitable to use in the context of agricultural decision support systems, in future work.

Comparison of Self-Declared Mobile Use While Driving in Canada, the United States, and Europe: Results from the European Survey of Road Users’ Safety Attitudes

Existing literature on hand-held mobile use while driving includes little research about the differences in prevalence worldwide. The current research aims to increase the available knowledge by comparing rates of self-reported hand-held mobile use behaviors while driving from three different regions (Canada, the United States, and Europe). Self-declared mobile use (talking on a hand-held mobile, sending a text message or email), personal acceptability, and attitudes toward mobile use while driving were measured as part of the E-Survey of Road Users’ Attitudes (ESRA 1) conducted in 25 countries during 2015–2016. Survey data was collected uniformly, allowing for full comparability among regions. The descriptive analysis compared rates of drivers’ mobile use behaviors, opinions, and attitudes by region. Two multivariate models predicting self-declared talking on a hand-held phone while driving, and self-declared sending of a text message or email while driving were also estimated. Regional comparisons of the descriptive results demonstrate that both self-declared behaviors were the lowest in Canada. Multivariate models show that U.S. drivers’ personal acceptability, attitudes, and support for zero-tolerance measures had a significant effect on their self-declared rates of hand-held mobile use while driving. Furthermore, when examining self-declared talking on a hand-held mobile device while driving across all regions, a common social phenomenon known as the bandwagon effect was found, as those who agreed that almost all car drivers occasionally talk on a hand-held mobile while driving were 2.41 times more likely to report doing so themselves. Implications and suggestions for further research are discussed.

Comparison of user satisfaction and image quality of fixed and mobile camera systems for 3-dimensional image capture of edentulous patients: A pilot clinical study

Statement of problemAn evaluation of user satisfaction and image quality of a novel handheld purpose-built mobile camera system for 3-dimensional (3D) facial acquisition is lacking. PurposeThe purpose of this pilot clinical study was to assess and compare the effectiveness between a handheld mobile camera system designed for facial acquisition and a fixed static camera arrangement by comparing the time effectiveness and the operator and participant preference for the 2 techniques of image capture. Material and methodsCompletely edentulous participants (n=12: women=7, men=5; mean age: 74.6 years) were included in this pilot study. Images were captured with and without the prostheses in situ while maintaining “serious” and “full-smile” facial expressions. Images were captured using a mobile and a static system. The working times for the participant installation and image captures were recorded. Operator and participant perceptions of the entire experience were recorded by using visual analog scale questionnaires. Nonparametric tests were used for statistical analyses (α=.05). ResultsThe installation time was significantly shorter for the mobile system (static=24 ±13 seconds; mobile=10 ±10 seconds), but the differences in the image capture times were not statistically significant (static: 29 ±5 seconds; mobile: 40 ±18 seconds). Operator preference was in favor of the mobile system with regard to working time (P=.002), difficulty in using (installation: P=.002; handling: P=.045), and camera weight (P=.002); however, they preferred the static arrangement for image quality (P=.003) and comfort (P=.013). The participants rated the entire photographic experience favorably, and 10 of 12 participants preferred the static camera over the mobile one. ConclusionsDespite the complexity of the installation, the static system was evaluated better for image quality; the mobile system was easier in installation and handling. The operators preferred the mobile system, and the participants preferred the static system.

Developing an Ornamental Fish Warehousing System Based on Big Video Data

We have developed an ornamental fish warehousing (OFWare) system based on big video data. The system is an application paradigm of information and communication technologies for traditional industries, specifically in the fields of aquaculture and agriculture. Live creatures are the main products of these industries, raising challenges for warehouse management. Warehousing of high unit-price ornamental fishes such as koi, stingray, and arowana is even more difficult since, in addition to counting and classification, such warehousing requires the identification of individual animals whose shapes and texture patterns vary as they grow. Therefore, rather than using invasive RFID-based systems, we combine mobile cloud computing and big data analytics techniques including image and video collection and transmission using handheld mobile devices, unsupervised texture pattern classification of fish tank videos, fish image retrieval, and statistical analysis. The proposed system is scalable based on a Hadoop framework and a small set of a single name-nodes and data-nodes can identify a particular fish among 500,000 koi in 7 seconds. The proposed warehousing system can form the basis for the development of breeding histories, anti-forgery certificate, and aquaculture business intelligence.

Compact feature subset-based multi-label music categorization for mobile devices

Music categorization based on acoustic features extracted from music clips and user-defined tags forms the basis of recent music recommendation applications, because relevant tags can be automatically assigned based on the feature values and their relation to tags. In practice, especially for handheld lightweight mobile devices, there is a certain limitation on the computational capacity, owing to consumers’ usage behavior or battery consumption. This also limits the maximum number of acoustic features to be extracted, and results in the necessity of identifying a compact feature subset that is used for the music categorization process. In this study, we propose an approach to compact feature subset-based multi-label music categorization for mobile music recommendation services. Experimental results using various multi-labeled music datasets reveal that the proposed approach yields better performance when compared to conventional approach.

The role of beliefs in the use of hands-free and handheld mobile phones while driving

Abstract Objective This study investigated the frequency of mobile phones use while driving by mode (handheld vs. hands-free users) and its relationship with three types of beliefs (behavioural, normative and control). Methods Three hundred and fourteen British drivers (M = 29.4 years; 64% female) completed a questionnaire (White et al., 2010) which measured frequency of mobile phone use while driving (in general, and for four specific phone-related behaviours) and the three types of beliefs. Results The proportion of participants who reported each behaviour on at least a daily basis were: 29% answering calls, 29% initiating calls, 30% reading texts and 22% sending texts. Significant multivariate differences were identified in the behavioural and control beliefs between daily and less frequent handheld mobile phone users. Differences were also found for several specific behavioural beliefs (effectively using time for both modes and receiving important information for handheld users), normative beliefs (handheld - partner, hands-free - friends, family and work colleagues) and control beliefs (hands-free - risk of fines, handheld - all control beliefs). In all cases daily users reported more positive outcomes of phone use, a higher likelihood of being approved by others, and a lower likelihood of control beliefs preventing them from using a phone. However, using composite measures of each belief type, logistic regression found that only control beliefs were significantly related to being a daily user among handheld mobile phone users. Conclusions Differences in beliefs (particularly behavioural and control beliefs) were found between daily and less frequent users of handheld mobile phones, meaning that they may underlie the decision to engage in this risky behaviour. Likewise, several specific beliefs differed between daily and less frequent users of handheld and hands-free mobile phones (using their time effectively). These results may provide useful information for developing countermeasures aimed at curbing mobile phone use while driving.

Instant Social Networking with Startup Time Minimization Based on Mobile Cloud Computing

Mobile communication and handheld devices are currently extremely popular, and provide people with convenient and instant platforms for social networking. However, existing social networking services cannot offer efficient human-machine interfaces or intuitive user experiences. Mobile users must manually input account information and find targets from search results when attempting to add someone to their friend list on social networking sites, such as Facebook and Twitter. Additionally, mobile users may not be able to identify correct targets because some usernames are identical. Typos may occur during the input process due to unfamiliar identifiers, further increasing the total operation time. To encourage social initiation between mobile users, we design an instant social networking framework, called SocialYou, to minimize the startup time based on mobile cloud computing. SocialYou proposes an efficient architecture and innovative human-machine interfaces to alleviate the complexity and difficulty for mobile users using handheld devices. In particular, we implement an Android-based prototype to verify the feasibility and superiority of SocialYou. The experimental results show that SocialYou outperforms the existing methods and saves substantial amounts of operation time for mobile social networking.

Next Generation Mobile Phone Antenna and its SAR Investigation

This work presents the design and Specific Absorption Rate (SAR) investigation of Fifth Generation (5G) antenna for future mobile communication networks. The radiating patch is made up of copper material backed by a 0.254 mm thicker Roggers-5880 substrate (N9000 PTFE) having relative permittivity and loss tangent of 22x10-1 and 9x10-4, correspondingly. The antenna resonates at 23 GHz frequency band. The major lobe gain of the single component 5G antenna is 7.16 dB.To meet the gain requirements of 5G mobile communication systems, 1 x 4 element array antenna has been proposed which increases the bore side gain up to 12.6 dB at the desired frequency. The proposed antennas efficiency is 91-94 % with a sufficient amount of driving point impedance bandwidth (S11<- 10 dB), i.e. 600-620 MHz;The SAR of the proposed antenna is analyzed at two different parts of human body, i.e. belly and hand. The SAR is averaged over 10g of tissue. The proposed 1 x 4 element antenna gives lower values of SAR (<2 W/kg) on all parts of human body. The proposed array antenna can be used in 5G mobile handheld devices. All the simulations are carried out using CST MWS. The proposed antenna is suitable contender for 5G mobile communication systems.

Comparison of beef traceability in serial and parallel fabrication systems using RFID and two-dimensional barcodes.

Traceability of beef attributes from small- and mid-sized farms through supply chains is a market barrier. The objective of this trial was to determine the influence of fabrication method on beef traceability system requirements. Individual identities of 54 animals were maintained through harvest, processing, packaging, and distribution. At harvest, each animal’s unique radio frequency identification (RFID) animal identification number was transferred to a harvest label on each carcass quarter. Following transportation to a processor, nine carcasses were processed on alternating days by one of the two methods. Carcasses were fabricated, using a serial fabrication method (SFM), into wholesale cuts one at a time or fabricated using a parallel fabrication method (PFM), by processing multiple hindquarters or forequarters simultaneously into wholesale cuts. In-process labels were generated by scanning the two-dimensional (2D) barcode on the harvest label with a handheld mobile computer and printed from a wireless mobile printer. Tracking of SFM and PFM carcass quarters was accomplished by creating in-process labels for lugs and individual wholesale cuts, respectively. The process was recorded and the data was captured from video analysis. The mean number of in-process labels generated per carcass for SFM was 3.7 and for PFM was 30.9 (P < 0.01). The amount of time required for generating in-process labels for SFM (2 min 16 s) was less than PFM (8 min 45 s) (P = 0.01). The amount of time required to label each carcass was less (P < 0.01) for SFM (18 s) than for PFM (3 min 10 s) with in-process labels. Total cost of traceability, including fixed and consumable cost per carcass, was nearly twice as much for PFM ($17.98) than SFM ($9.02). Traceability, within both processing methods, was found to have 100% fidelity, as verified using DNA marker genotyping. Overall, the number of labels generated for traceability was less for SFM than that for PFM. The overall time spent on generating, applying, and removing labels was less for SFM than that for PFM. The total cost of traceability was approximately half for SFM compared with that for PFM; however both methods were able to track product accurately. Tracking of beef from individual animals, using RFID ear tags and 2D barcodes, appears to be feasible for the fabrication methods used in this study.

A Localized Meshless Technique for Generating 3-D Wind Fields

A localized meshless method is used to simulate 3-D atmospheric wind fields for wind energy assessment and emergency response. The meshless (or mesh-free) method with radial basis functions (RBFs) alleviates the need to create a mesh required by finite difference, finite volume, and finite element methods. The method produces a fast solution that converges with high accuracy, establishing 3-D wind estimates over complex terrain. The method does not require discretization of the domain or boundary and removes the need for domain integration. The meshless method converges exponentially for smooth boundary shapes and boundary data, and is insensitive to dimensional constraints. Coding of the method is very easy and can be done using MATLAB or MAPLE. By employing a localized RBF procedure, 3-D wind fields can be established from sparse meteorological data. The meshless method can be easily run on PCs and hand-held mobile devices. This article summarizes previous work where the meshless method has successfully simulated 3D wind fields over various environments, along with the equations used to obtain the simulations.

Smartphones and Semen Analysis.

In March 1876, when the telephone pioneer Alexander Graham Bell made his historic call to his assistant, Thomas Watson, it is unlikely that either one of them envisaged other applications for a phone, let alone the medical application of a phone that was published in March 2017 by Shafiee and colleagues in Science Translational Medicine (1) (Figure 1). It is equally unlikely that they would have believed that nearly 150 years later there would be mobile phones or that there would be more mobile phones than people on the planet. Fig. 1. Historical progress of the telephone from Alexander Graham Bell to modern-day smartphone-based semen analysis. Bell on the telephone in New York calling Chicago in 1892 \[Gilbert H. Grosvenor Collection, Prints and Photographs Division, Library of Congress. (Public domain), via Wikimedia Commons\] (https://commons.wikimedia.org/wiki/File:Alexander\_Graham\_Telephone\_in\_Newyork.jpg) (Accessed April 2017) (A). Smartphone semen testing (a. optical attachment, b. microfluidic chip) (Image courtesy of Hadi Shafiee) (1) (B). Modern-day hand-held mobile telephony can be traced back to the early 1970s, and the technology has evolved into the current app-laden “smartphone” that combines communication (voice, data, internet) and data storage capabilities with the features of other devices, such as an MP3 player and a digital camera/video camera. Smartphones have created interesting opportunities in wellness medical care and in diagnostic testing. There are now many apps available aimed at …

Combination of MIMO Antennas for Handheld Devices [Wireless Corner

With the development of the fourth-generation (4G) and fifth-generation (5G) wireless systems and the high-data transmission rate requirements, multiple-input, multiple-output (MIMO) antennas are becoming necessary in mobile terminals. Handheld mobile devices support various service standards, such as Wi-Fi, LTE, Wi-Max, personal communications service, and digital cellular systems.

Cummings, Merrill, and Borrelli’s Inquiry into Small Screen Use by Academic Library Users: Timing is Everything

A Review of: Cummings, J., Merrill, A., &amp; Borrelli, S. (2010). The use of handheld mobile devices: Their impact and implications for library services. Library Hi Tech, (28)1, 22-40. https://doi.org/10.1108/07378831011026670&#x0D; Abstract &#x0D; Objective – The authors undertook this study to understand the relatively new phenomenon of handheld computing and the use of small-screen devices among academic library users. They sought to determine if users would be inclined to search the online library catalogue on their devices and, by extension, if there would be a growing demand for small-screen compatible library services.&#x0D; Design – Online and paper surveys were used with both closed and open questions. Respondents included students, faculty, and staff at Washington State University (WSU).&#x0D; Setting – Washington State University Library, Pullman, Washington, United States of America. Subjects – The survey was open to any user of the Washington State University (Pullman) Library. The 206 respondents included 126 (61.2%) undergraduates, 26 (12.6%) graduate or professional students, 32 (15.3%) WSU employees, and 15 (7.3%) faculty members. Methods – A survey was distributed both online and on paper. The online version used Surveymonkey.com and participation was solicited through various social media. It was open for three months during the Spring semester, 2007. The paper version was distributed to all library users on two days in June 2007. Eighty-four online and 122 paper responses were received.&#x0D; Main Results – Most of the respondents (58.4%) who owned a personal digital assistant (PDA) or Web-enabled cell phone (WECP) indicated that they would search the library catalogue on a small-screen device. Responses to the open question “How would you use the OPAC [online public access catalogue] if it was available on a PDA or WECP?” were mixed, both positive and negative. The positive responders noted the possible time savings associated with the availability of more information on their devices. The negative responders noted the cost of data, the annoyance of public phone use, and the complex format of the current catalogue that would not transfer to a small screen.&#x0D; Conclusion – The authors cited the growing usage trends in handheld devices, along with the willingness of current owners to use their devices, to predict an increase in usage of small screen searching. They speculated that further research should investigate how small screens would be used and what would that experience look like, rather than if patrons would use them.

Mobile augmented reality applications for construction projects

PurposeThe purpose of this paper is to facilitate the process of monitoring construction projects. Classic practice for construction progress tracking relies on paper reports, which entails a serious amount of manual data collection as well as the effort of imagining the actual progress from the paperwork.Design/methodology/approachThis paper presents a new methodology for monitoring construction progress using smartphones. This is done by proposing a new system consisting of a newly-developed application named “BIM-U” and a mobile augmented reality (AR) channel named “BIM-Phase”. “BIM-U” is an Android application that allows the end-user to update the progress of activities onsite. These data are used to update the project’s 4D model enhanced with different cost parameters such as earned value, actual cost and planned value. The “BIM-Phase” application is a mobile AR channel that is used during construction phase through implementing a 4D “as-planned” phased model integrated with an augmented video showing real or planned progress.FindingsThe results from the project are then analysed and assessed to anticipate the potential of these and similar techniques for tracking time and cost on construction projects.Originality/valueThe proposed system through “BIM-U” and “BIM Phase” exploits the potential of mobile applications and AR in construction through the use of handheld mobile devices to offer new possibilities for measuring and monitoring work progress using building information modelling.

Mobile phone use while driving and the risk of collision: A study among preparatory year students at King Saud University, Riyadh, Saudi Arabia.

OBJECTIVES:The objectives of this study were to determine the rate of mobile phones use while driving by the students of King Saud University, Riyadh, Saudi Arabia, their perception of the risks, and contribution to collisions.MATERIALS AND METHODS:A cross-sectional study was conducted in May 2014 targeting 986 male students of King Saud University, Riyadh, Saudi Arabia. A questionnaire was used to obtain data on possessing a driving license, years of driving experience, driving hours, and collision or near misses in the 6 months preceding the study. Eight statements were used to assess the behavior and perceptions related to the use of mobile phones while driving. Data were analyzed using the Chi-square statistic, odds ratio, and the 95% confidence interval.RESULTS:Almost half of the participants (45.3%) had driving experience of 4–6 years and 18.3% of them did not possess a driving license. Collision in the preceding 6 months was reported by 44.6% of participants, and 37.9% of them attributed these collisions to mobile phones. Variable proportions reported that they always texted (53.3%) or talked on a handheld (66.2%) or hands-free (26.1%) phones while driving. A higher proportion conceded that there were hazards in texting (77.0%) and speaking on handheld mobile phones (83.9%) rather than hands-free (35.9%) while driving. The risk increased significantly from 2.052 among participants who reported that they drove daily for 1–2 h to 3.165 of those who reported that they drove for more than 6 h. No significant risk was observed in relation to participants' perceptions, age, driving experience, and possession of a driving license.CONCLUSIONS:There was a risk of collision with the use of handheld and hands-free mobile phones. As hands-free mobile phones are no safer, national legislation should consider restricting their use by drivers and implementing legislations to reinforce safety on the roads. An objective assessment of the contribution of mobile phones to road traffic injuries is recommended.

TPP: Trajectory Privacy Preservation Against Tensor Voting Based Inference Attacks

The popularity of mobile devices with global positioning system (GPS) has boosted various wireless location-based services (LBSs). Certain honest-but-curious or even dishonest LBS servers may learn the users’ trajectories from location trace files, and the users’ privacy can be compromised. In this paper, we propose a quantitative approach to model trajectory inference attacks via tensor voting, which can be widely applied in computer vision and machine learning as a perceptual organization. To counter the tensor voting based attacks, we propose a novel trajectory privacy preservation TPP scheme, in which LBS users will intentionally generate dummy trajectories to obfuscate LBS servers. Meanwhile, the LBS users have the option to disclose their trajectories to trustworthy parties (e.g., users’ parents) by sending those parties a few more encrypted locations. Considering the power constraint of hand-held mobile devices, we mathematically formulate the trajectory privacy preservation problem into a mixed integer linear programming optimization problem and propose the algorithms for optimizing solutions. Through simulations and analysis, we show that the proposed scheme can effectively preserve LBS users’ trajectory privacy against tensor voting-based inference attacks with limited power consumption.

Integrating terrestrial and airborne laser scanning for the assessment of single-tree attributes in Mediterranean forest stands

ABSTRACTThe development of laser scanning technologies has gradually modified methods for forest mensuration and inventory. The main objective of this study is to assess the potential of integrating ALS and TLS data in a complex mixed Mediterranean forest for assessing a set of five single-tree attributes: tree position (TP), stem diameter at breast height (DBH), tree height (TH), crown base height (CBH) and crown projection area radii (CPAR). Four different point clouds were used: from ZEB1, a hand-held mobile laser scanner (HMLS), and from FARO® FOCUS 3D, a static terrestrial laser scanner (TLS), both alone or in combination with ALS. The precision of single-tree predictions, in terms of bias and root mean square error, was evaluated against data recorded manually in the field with traditional instruments. We found that: (i) TLS and HMLS have excellent comparable performances for the estimation of TP, DBH and CPAR; (ii) TH was correctly assessed by TLS, while the accuracy by HMLS was lower; (iii) CBH was the most difficult attribute to be reliably assessed and (iv) the integration with ALS increased the performance of the assessment of TH and CPAR with both HMLS and TLS.

Dynamic Video Stitching via Shakiness Removing.

Stitching videos captured by hand-held mobile cameras can essentially enhance entertainment experience of ordinary users. However, such videos usually contain heavy shakiness and large parallax, which are challenging to stitch. In this paper, we propose a novel approach of video stitching and stabilization for videos captured by mobile devices. The main component of our method is a unified video stitching and stabilization optimization that computes stitching and stabilization simultaneously rather than does each one individually. In this way, we can obtain the best stitching and stabilization results relative to each other without any bias to one of them. To make the optimization robust, we propose a method to identify background of input videos, and also common background of them. This allows us to apply our optimization on background regions only, which is the key to handle large parallax problem. Since stitching relies on feature matches between input videos, and there inevitably exist false matches, we thus propose a method to distinguish between right and false matches, and encapsulate the false match elimination scheme and our optimization into a loop, to prevent the optimization from being affected by bad feature matches. We test the proposed approach on videos that are causally captured by smartphones when walking along busy streets, and use stitching and stability scores to evaluate the produced panoramic videos quantitatively. Experiments on a diverse of examples show that our results are much better than (challenging cases) or at least on par with (simple cases) the results of previous approaches.Stitching videos captured by hand-held mobile cameras can essentially enhance entertainment experience of ordinary users. However, such videos usually contain heavy shakiness and large parallax, which are challenging to stitch. In this paper, we propose a novel approach of video stitching and stabilization for videos captured by mobile devices. The main component of our method is a unified video stitching and stabilization optimization that computes stitching and stabilization simultaneously rather than does each one individually. In this way, we can obtain the best stitching and stabilization results relative to each other without any bias to one of them. To make the optimization robust, we propose a method to identify background of input videos, and also common background of them. This allows us to apply our optimization on background regions only, which is the key to handle large parallax problem. Since stitching relies on feature matches between input videos, and there inevitably exist false matches, we thus propose a method to distinguish between right and false matches, and encapsulate the false match elimination scheme and our optimization into a loop, to prevent the optimization from being affected by bad feature matches. We test the proposed approach on videos that are causally captured by smartphones when walking along busy streets, and use stitching and stability scores to evaluate the produced panoramic videos quantitatively. Experiments on a diverse of examples show that our results are much better than (challenging cases) or at least on par with (simple cases) the results of previous approaches.