Change search
Link to record
Permanent link

Direct link
BETA
Dahl, Mattias
Publications (10 of 91) Show all publications
Javadi, M. S., Dahl, M. & Pettersson, M. (2020). Adjustable Contrast Enhancement Using Fast Piecewise Linear Histogram Equalization. In: ACM International Conference Proceeding Series: . Paper presented at 3rd International Conference on Image and Graphics Processing, ICIGP 2020; Singapore; 8 February 2020 through 10 February 2020 (pp. 57-61). Association for Computing Machinery
Open this publication in new window or tab >>Adjustable Contrast Enhancement Using Fast Piecewise Linear Histogram Equalization
2020 (English)In: ACM International Conference Proceeding Series, Association for Computing Machinery , 2020, p. 57-61Conference paper, Published paper (Refereed)
Abstract [en]

Histogram equalization is a technique to enhance the contrast of the image by redistributing the histogram. In this paper, a fast piecewise linear histogram equalization method is introduced based on an adjustable degree of enhancement and piecewise continuous transformation functions using frequencies of different grey-levels. This method aims to address and maximize the contrast enhancement of the image by stretching the entire spectrum. For this purpose, particular nodes (bins) on the histogram are simultaneously detected that in comparison with recursive methods, it requires less computational time. Then, the particular nodes are stretched using transformation functions to align with the reference nodes. The experimental results indicate that the performance of the proposed method is promising in terms of contrast enhancement. Moreover, this method preserves the texture of various regions in the image very well through the equalization process by using the degree of enhancement. © 2020 Owner/Author.

Place, publisher, year, edition, pages
Association for Computing Machinery, 2020
Keywords
Contrast enhancement, Histogram equalization, Histogram modification, Image/video enhancement, Equalizers, Graphic methods, Linear transformations, Piecewise linear techniques, Textures, Computational time, Histogram equalizations, Piecewise linear, Piecewise-continuous, Recursive methods, Reference nodes, Transformation functions, Image enhancement
National Category
Control Engineering
Identifiers
urn:nbn:se:bth-19394 (URN)10.1145/3383812.3383830 (DOI)2-s2.0-85083108101 (Scopus ID)9781450377201 (ISBN)
Conference
3rd International Conference on Image and Graphics Processing, ICIGP 2020; Singapore; 8 February 2020 through 10 February 2020
Note

Sponsor: Nanyang Technological University,University of Bologna (UNIBO)

Open Access

Available from: 2020-04-24 Created: 2020-04-24 Last updated: 2020-04-24Bibliographically approved
Dahl, M. & Javadi, M. S. (2020). Analytical Modeling for a Video-Based Vehicle Speed Measurement Framework. Sensors, 20(1), Article ID 160.
Open this publication in new window or tab >>Analytical Modeling for a Video-Based Vehicle Speed Measurement Framework
2020 (English)In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 20, no 1, article id 160Article in journal (Refereed) Published
Abstract [en]

 Traffic analyses, particularly speed measurements, are highly valuable in terms of road safety and traffic management. In this paper, an analytical model is presented to measure the speed of a moving vehicle using an off-the-shelf video camera. The method utilizes the temporal sampling rate of the camera and several intrusion lines in order to estimate the probability density function (PDF) of a vehicle’s speed. The proposed model provides not only an accurate estimate of the speed, but also the possibility of being able to study the performance boundaries with respect to the camera framerate as well as the placement and number of intrusion lines in advance. This analytical modelis verified by comparing its PDF outputs with the results obtained via a simulation of the corresponding movements. In addition,as aproof-of-concept, the proposed model is implemented for avideo-based vehicle speed measurement system. The experimental results demonstrate the model’s capability in terms of taking accurate measurements of the speed via a consideration of the temporal sampling rate and lowering the deviation by utilizing more intrusion lines. The analytical model is highly versatile and can be used as the core of various video-based speed measurement systems in transportation and surveillance applications.

Keywords
vehicle speed measurement; temporal sampling; analytical modeling; motion analysis; pattern recognition; image processing
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-17160 (URN)10.3390/s20010160 (DOI)000510493100160 ()2-s2.0-85077333600 (Scopus ID)
Note

open access

Available from: 2018-10-23 Created: 2018-10-23 Last updated: 2020-02-20Bibliographically approved
Javadi, M. S., Dahl, M. & Pettersson, M. (2020). Change detection in aerial images using three-dimensional feature maps [Letter to the editor]. Remote Sensing, 12(9), Article ID 1404.
Open this publication in new window or tab >>Change detection in aerial images using three-dimensional feature maps
2020 (English)In: Remote Sensing, ISSN 2072-4292, E-ISSN 2072-4292, Vol. 12, no 9, article id 1404Article in journal, Letter (Refereed) Published
Abstract [en]

Interest in aerial image analysis has increased owing to recent developments in and availabilityofaerialimagingtechnologies,likeunmannedaerialvehicles(UAVs),aswellasagrowing need for autonomous surveillance systems. Variant illumination, intensity noise, and different viewpointsareamongthemainchallengestoovercomeinordertodeterminechangesinaerialimages. In this paper, we present a robust method for change detection in aerial images. To accomplish this, the method extracts three-dimensional (3D) features for segmentation of objects above a defined reference surface at each instant. The acquired 3D feature maps, with two measurements, are then used to determine changes in a scene over time. In addition, the important parameters that affect measurement, such as the camera’s sampling rate, image resolution, the height of the drone, and the pixel’sheightinformation,areinvestigatedthroughamathematicalmodel. Toexhibititsapplicability, the proposed method has been evaluated on aerial images of various real-world locations and the results are promising. The performance indicates the robustness of the method in addressing the problems of conventional change detection methods, such as intensity differences and shadows.

Place, publisher, year, edition, pages
MDPI, 2020
Keywords
aerial images; 3D change detection; optical vehicle surveillance; remote sensing; unmanned aerial vehicle
National Category
Signal Processing Computer Vision and Robotics (Autonomous Systems)
Identifiers
urn:nbn:se:bth-19422 (URN)10.3390/rs12091404 (DOI)
Note

open access

Available from: 2020-05-01 Created: 2020-05-01 Last updated: 2020-06-05Bibliographically approved
Rameez, M., Dahl, M. & Pettersson, M. (2020). Experimental Evaluation of Adaptive Beamforming for Automotive Radar Interference Suppression. In: IEEE Radio and Wireless Symposium, RWS: . Paper presented at IEEE Radio and Wireless Symposium, RWW 2020; San Antonio; United States; 26 January 2020 through 29 January 2020 (pp. 183-186). IEEE, Article ID 9049982.
Open this publication in new window or tab >>Experimental Evaluation of Adaptive Beamforming for Automotive Radar Interference Suppression
2020 (English)In: IEEE Radio and Wireless Symposium, RWS, IEEE, 2020, p. 183-186, article id 9049982Conference paper, Published paper (Refereed)
Abstract [en]

Mutual interference between automotive radars can make it difficult to detect targets, especially the weaker ones, such as cyclists and pedestrians. In this paper, the interference suppression performance of a Least Mean Squares (LMS) algorithm-based adaptive beamformer is evaluated using measurements from a 77 GHz Frequency Modulated Continuous Wave (FMCW) radar in an outdoor environment. It is shown that the adaptive beamformer increases detection performance and that the interference is suppressed down to the noise floor of the radar in the Range-Doppler domain. In the paper, real baseband sampling and complex-baseband sampling (IQ) radar receivers are compared in the context of interference suppression. The measurements show that IQ receivers are more beneficial in the presence of interference.

Place, publisher, year, edition, pages
IEEE, 2020
Keywords
Automotive radar, Frequency Modulated Continuous Wave (FMCW), interference mitigation, digital beamforming
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-19368 (URN)10.1109/RWS45077.2020.9049982 (DOI)
Conference
IEEE Radio and Wireless Symposium, RWW 2020; San Antonio; United States; 26 January 2020 through 29 January 2020
Note

Sponsorer: AESS,APS,IEEE,MTT-S

Available from: 2020-04-07 Created: 2020-04-07 Last updated: 2020-04-24Bibliographically approved
Vu, V. T., Pettersson, M., Dahl, M. & Sjögren, T. K. (2019). A MEASUREMENT CAMPAIGN IN HARBOR TO DETECT CHANGES OF ACTIVITIES. In: 2019 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM (IGARSS 2019): . Paper presented at IEEE International Geoscience and Remote Sensing Symposium (IGARSS), JUL 28-AUG 02, 2019, Yokohama, JAPAN (pp. 1494-1497). IEEE
Open this publication in new window or tab >>A MEASUREMENT CAMPAIGN IN HARBOR TO DETECT CHANGES OF ACTIVITIES
2019 (English)In: 2019 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM (IGARSS 2019), IEEE , 2019, p. 1494-1497Conference paper, Published paper (Refereed)
Abstract [en]

The typical activities in a harbor mainly concern logistics, traffic and transportation that need to be monitored or optimized. This paper reports a measurement campaign whose goal is to evaluate the performance of activity surveillance in a harbor using satellite SAR systems. The measurements were conducted in the southern Baltic sea, around the Verko harbor in Karlskrona, Sweden in the middle of 2018. The SAR data acquisition was with TerraSAR-X/TanDEM-X operating in staring spotlight mode as high resolution was desired. For an accurate evaluation, all activities in the Verko harbor were video recorded by a drone during the satellite measurement time. Some radar corner reflectors were also deployed on the ground that are available for co-registration. The data associated with two measurements in the end of August and in the beginning of September is presented in this paper. The SAR change detection processing and the initial analysis show the possibility to monitor activities concerning logistics, traffic and transportation using satellite SAR.

Place, publisher, year, edition, pages
IEEE, 2019
Series
IEEE International Symposium on Geoscience and Remote Sensing IGARSS, ISSN 2153-6996
Keywords
Transport monitoring, TerraSAR-X/TanDEM-X, Bayes' theorem, multivariate distribution
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering Remote Sensing
Identifiers
urn:nbn:se:bth-19386 (URN)000519270601182 ()978-1-5386-9154-0 (ISBN)
Conference
IEEE International Geoscience and Remote Sensing Symposium (IGARSS), JUL 28-AUG 02, 2019, Yokohama, JAPAN
Available from: 2020-04-16 Created: 2020-04-16 Last updated: 2020-04-16Bibliographically approved
Pettersson, M., Dahl, M., Vu, V. T. & Javadi, M. S. (2019). Future Satellite and Drone Monitoring of the Baltic‐Adriatic Corridor,Harbors, and Motorways of the Sea.
Open this publication in new window or tab >>Future Satellite and Drone Monitoring of the Baltic‐Adriatic Corridor,Harbors, and Motorways of the Sea
2019 (English)Report (Other academic)
Publisher
p. 50
National Category
Engineering and Technology
Identifiers
urn:nbn:se:bth-18575 (URN)
Projects
Tentacle
Available from: 2019-09-04 Created: 2019-09-04 Last updated: 2019-09-06Bibliographically approved
Fredriksson, H., Dahl, M. & Holmgren, J. (2019). Optimal placement of charging stations for electric vehicles in large-scale transportation networks. In: Shakshuki, E; Yasar, A; Malik, H (Ed.), Procedia Computer Science: . Paper presented at 10th International Conference on Emerging Ubiquitous Systems and Pervasive Networks, EUSPN 2019 and 9th International Conference on Current and Future Trends of Information and Communication Technologies in Healthcare, ICTH 2019, Affiliated Workshops; Coimbra; Portugal; 4 November (pp. 77-84). Elsevier B.V., 160
Open this publication in new window or tab >>Optimal placement of charging stations for electric vehicles in large-scale transportation networks
2019 (English)In: Procedia Computer Science / [ed] Shakshuki, E; Yasar, A; Malik, H, Elsevier B.V. , 2019, Vol. 160, p. 77-84Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a new practical approach to optimally allocate charging stations in large-scale transportation networks for electric vehicles (EVs). The problem is of particular importance to meet the charging demand of the growing fleet of alternative fuel vehicles. Considering the limited driving range of EVs, there is need to supply EV owners with accessible charging stations to reduce their range anxiety. The aim of the Route Node Coverage (RNC) problem, which is considered in the current paper, is to find the minimum number of charging stations, and their locations in order to cover the most probable routes in a transportation network. We propose an iterative approximation technique for RNC, where the associated Integer Problem (IP) is solved by exploiting a probabilistic random walk route selection, and thereby taking advantage of the numerical stability and efficiency of the standard IP software packages. Furthermore, our iterative RNC optimization procedure is both pertinent and straightforward to implement in computer coding and the design technique is therefore highly applicable. The proposed optimization technique is applied on the Sioux-Falls test transportation network, and in a large-scale case study covering the southern part of Sweden, where the focus is on reaching the maximum coverage with a minimum number of charging stations. The results are promising and show that the flexibility, smart route selection, and numerical efficiency of the proposed design technique, can pick out strategic locations for charging stations from thousands of possible locations w ithout numerical difficulties. ©2019 Hie Authors. Published by Elsevier B.V.

Place, publisher, year, edition, pages
Elsevier B.V., 2019
Keywords
Charging stations, Clectric vehicle, Optimal placement, Route node coverage, Transportation network, Charging (batteries), Data communication systems, Efficiency, Electric vehicles, Fleet operations, Health care, Internet protocols, Iterative methods, Location, Alternative fuel vehicles, Charging station, Iterative approximations, Large-scale transportation, Node coverage, Optimal placements, Optimization techniques, Transportation routes
National Category
Transport Systems and Logistics Energy Systems
Identifiers
urn:nbn:se:bth-19238 (URN)10.1016/j.procs.2019.09.446 (DOI)000515510100010 ()2-s2.0-85079099240 (Scopus ID)
Conference
10th International Conference on Emerging Ubiquitous Systems and Pervasive Networks, EUSPN 2019 and 9th International Conference on Current and Future Trends of Information and Communication Technologies in Healthcare, ICTH 2019, Affiliated Workshops; Coimbra; Portugal; 4 November
Note

open access

Available from: 2020-02-20 Created: 2020-02-20 Last updated: 2020-05-29
Javadi, M. S., Dahl, M. & Pettersson, M. (2019). Vehicle speed measurement model for video-based systems. Computers & electrical engineering, 76, 238-248
Open this publication in new window or tab >>Vehicle speed measurement model for video-based systems
2019 (English)In: Computers & electrical engineering, ISSN 0045-7906, E-ISSN 1879-0755, Vol. 76, p. 238-248Article in journal (Refereed) Published
Abstract [en]

Advanced analysis of road traffic data is an essential component of today's intelligent transportation systems. This paper presents a video-based vehicle speed measurement system based on a proposed mathematical model using a movement pattern vector as an input variable. The system uses the intrusion line technique to measure the movement pattern vector with low computational complexity. Further, the mathematical model introduced to generate the pdf (probability density function) of a vehicle's speed that improves the speed estimate. As a result, the presented model provides a reliable framework with which to optically measure the speeds of passing vehicles with high accuracy. As a proof of concept, the proposed method was tested on a busy highway under realistic circumstances. The results were validated by a GPS (Global Positioning System)-equipped car and the traffic regulations at the measurement site. The experimental results are promising, with an average error of 1.77 % in challenging scenarios.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Intelligent transportation systems; Machine vision; Motion analysis; Pattern recognition; Speed measurement system
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-17161 (URN)10.1016/j.compeleceng.2019.04.001 (DOI)000470954900019 ()
Note

open access

Available from: 2018-10-23 Created: 2018-10-23 Last updated: 2019-06-27Bibliographically approved
Rameez, M., Dahl, M. & Pettersson, M. (2018). Adaptive digital beamforming for interference suppression in automotive FMCW radars. In: 2018 IEEE Radar Conference, (RadarConf 2018): . Paper presented at 2018 IEEE Radar Conference,Oklahoma City (pp. 252-256). Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>Adaptive digital beamforming for interference suppression in automotive FMCW radars
2018 (English)In: 2018 IEEE Radar Conference, (RadarConf 2018), Institute of Electrical and Electronics Engineers Inc. , 2018, p. 252-256Conference paper, Published paper (Refereed)
Abstract [en]

This paper addresses the problem of mutual interference between automotive radars. This problem is getting more attention with an increase in the number of radar systems used in traffic. An adaptive digital beamforming technique is presented here which suppresses the interference without the exact knowledge of the interfering signal's Direction of Arrival (DoA). The proposed technique is robust and does not rely on any calibration for the interference cancellation. The adaptive interference suppression method is evaluated using a simulated scenario. Up to about 20-23 dB improvement in the target Signal to Interference and Noise Ratio (SINR) is measured in the simulation and a better detection performance is achieved using the proposed interference suppression technique. © 2018 IEEE.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Series
IEEE Radar Conference
Keywords
Beamforming, Frequency modulation, Radar systems, Signal to noise ratio, Adaptive digital beamforming, Adaptive interference suppression, Automotive radar, Detection performance, Interference cancellation, Interfering signals, Mutual interference, Target signals, Radar interference
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-16910 (URN)10.1109/RADAR.2018.8378566 (DOI)000442172700046 ()2-s2.0-85049977586 (Scopus ID)978-1-5386-4167-5 (ISBN)
Conference
2018 IEEE Radar Conference,Oklahoma City
Available from: 2018-08-20 Created: 2018-08-20 Last updated: 2020-04-07Bibliographically approved
Javadi, M. S., Dahl, M., Pettersson, M. & Kulesza, W. (2018). Design of a video-based vehicle speed measurement system: an uncertainty approach. In: 2018 Joint 7th International Conference on Informatics, Electronics & Vision (ICIEV) and 2018 2nd International Conference on Imaging, Vision & Pattern Recognition (icIVPR), Kitakyushu, Japan, 2018, pp. 44-49.: . Paper presented at Joint 7th International Conference on Informatics, Electronics and Vision and 2nd International Conference on Imaging, Vision and Pattern Recognition, ICIEV-IVPR 2018; Kitakyushu; Japan; 25-28 June 2018. IEEE, Article ID 8640964.
Open this publication in new window or tab >>Design of a video-based vehicle speed measurement system: an uncertainty approach
2018 (English)In: 2018 Joint 7th International Conference on Informatics, Electronics & Vision (ICIEV) and 2018 2nd International Conference on Imaging, Vision & Pattern Recognition (icIVPR), Kitakyushu, Japan, 2018, pp. 44-49., IEEE, 2018, article id 8640964Conference paper, Published paper (Refereed)
Abstract [en]

Speed measurement is one of the key components of intelligent transportation systems. It provides suitable information for traffic management and law enforcement. This paper presents a versatile and analytical model for a video-based speed measurement in form of the probability density function (PDF). In the proposed model, the main factors contributing to the uncertainties of the measurement are considered. Furthermore, a guideline is introduced in order to design a video-based speed measurement system based on the traffic and other requirements. As a proof of concept, the model has been simulated and tested for various speeds. An evaluation validates the strength of the model for accurate speed measurement under realistic circumstances.

Place, publisher, year, edition, pages
IEEE, 2018
Keywords
Intelligent transportation systems, Machine vision, Motion analysis, Pattern recognition, Speed measurement
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-17163 (URN)10.1109/ICIEV.2018.8640964 (DOI)000462610300008 ()9781538651612 (ISBN)
Conference
Joint 7th International Conference on Informatics, Electronics and Vision and 2nd International Conference on Imaging, Vision and Pattern Recognition, ICIEV-IVPR 2018; Kitakyushu; Japan; 25-28 June 2018
Available from: 2018-10-23 Created: 2018-10-23 Last updated: 2020-01-24Bibliographically approved
Organisations

Search in DiVA

Show all publications