Change search
Link to record
Permanent link

Direct link
BETA
Wen, Wei
Publications (10 of 11) Show all publications
Jerčić, P., Wen, W., Hagelbäck, J. & Sundstedt, V. (2018). The Effect of Emotions and Social Behavior on Performance in a Collaborative Serious Game Between Humans and Autonomous Robots. International Journal of Social Robotics, 10(1), 115-129
Open this publication in new window or tab >>The Effect of Emotions and Social Behavior on Performance in a Collaborative Serious Game Between Humans and Autonomous Robots
2018 (English)In: International Journal of Social Robotics, ISSN 1875-4791, E-ISSN 1875-4805, Vol. 10, no 1, p. 115-129Article in journal (Refereed) Published
Abstract [en]

The aim of this paper is to investigate performance in a collaborative human–robot interaction on a shared serious game task. Furthermore, the effect of elicited emotions and perceived social behavior categories on players’ performance will be investigated. The participants collaboratively played a turn-taking version of the Tower of Hanoi serious game, together with the human and robot collaborators. The elicited emotions were analyzed in regards to the arousal and valence variables, computed from the Geneva Emotion Wheel questionnaire. Moreover, the perceived social behavior categories were obtained from analyzing and grouping replies to the Interactive Experiences and Trust and Respect questionnaires. It was found that the results did not show a statistically significant difference in participants’ performance between the human or robot collaborators. Moreover, all of the collaborators elicited similar emotions, where the human collaborator was perceived as more credible and socially present than the robot one. It is suggested that using robot collaborators might be as efficient as using human ones, in the context of serious game collaborative tasks.

Place, publisher, year, edition, pages
Springer, 2018
Keywords
Autonomous robots, Serious games, Collaborative play, Social interaction, Robot-assisted play, Emotions
National Category
Computer Systems
Identifiers
urn:nbn:se:bth-15541 (URN)10.1007/s12369-017-0437-4 (DOI)000423152900008 ()
Projects
PsyIntEC
Funder
EU, FP7, Seventh Framework Programme, FP7-ICT-231143
Note

open access

Available from: 2017-11-28 Created: 2017-11-28 Last updated: 2018-02-09Bibliographically approved
Wen, W. & Khatibi, S. (2018). The impact of curviness on four different image sensor forms and structures. Sensors, 18(2), Article ID 429.
Open this publication in new window or tab >>The impact of curviness on four different image sensor forms and structures
2018 (English)In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 18, no 2, article id 429Article in journal (Refereed) Published
Abstract [en]

The arrangement and form of the image sensor have a fundamental effect on any further image processing operation and image visualization. In this paper, we present a software-based method to change the arrangement and form of pixel sensors that generate hexagonal pixel forms on a hexagonal grid. We evaluate four different image sensor forms and structures, including the proposed method. A set of 23 pairs of images; randomly chosen, from a database of 280 pairs of images are used in the evaluation. Each pair of images have the same semantic meaning and general appearance, the major difference between them being the sharp transitions in their contours. The curviness variation is estimated by effect of the first and second order gradient operations, Hessian matrix and critical points detection on the generated images; having different grid structures, different pixel forms and virtual increased of fill factor as three major properties of sensor characteristics. The results show that the grid structure and pixel form are the first and second most important properties. Several dissimilarity parameters are presented for curviness quantification in which using extremum point showed to achieve distinctive results. The results also show that the hexagonal image is the best image type for distinguishing the contours in the images. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.

Place, publisher, year, edition, pages
MDPI AG, 2018
Keywords
Critical points, Curviness quantification, Fill factor, Grid structure, Hessian matrix, Hexagonal image, Pixel form, Software-based, Virtual, Image processing, Image sensors, Semantics, Grid structures, Hessian matrices, Pixels
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-15920 (URN)10.3390/s18020429 (DOI)000427544000112 ()2-s2.0-85041511195 (Scopus ID)
Note

open access

Available from: 2018-02-22 Created: 2018-02-22 Last updated: 2018-04-26Bibliographically approved
Wen, W. & Khatibi, S. (2018). Virtual deformable image sensors: Towards to a general framework for image sensors with flexible grids and forms. Sensors, 18(6), Article ID 1856.
Open this publication in new window or tab >>Virtual deformable image sensors: Towards to a general framework for image sensors with flexible grids and forms
2018 (English)In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 18, no 6, article id 1856Article in journal (Refereed) Published
Abstract [en]

Our vision system has a combination of different sensor arrangements from hexagonal to elliptical ones. Inspired from this variation in type of arrangements we propose a general framework by which it becomes feasible to create virtual deformable sensor arrangements. In the framework for a certain sensor arrangement a configuration of three optional variables are used which includes the structure of arrangement, the pixel form and the gap factor. We show that the histogram of gradient orientations of a certain sensor arrangement has a specific distribution (called ANCHOR) which is obtained by using at least two generated images of the configuration. The results showed that ANCHORs change their patterns by the change of arrangement structure. In this relation pixel size changes have 10-fold more impact on ANCHORs than gap factor changes. A set of 23 images; randomly chosen from a database of 1805 images, are used in the evaluation where each image generates twenty-five different images based on the sensor configuration. The robustness of ANCHORs properties is verified by computing ANCHORs for totally 575 images with different sensor configurations. We believe by using the framework and ANCHOR it becomes feasible to plan a sensor arrangement in the relation to a specific application and its requirements where the sensor arrangement can be planed even as combination of different ANCHORs. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.

Place, publisher, year, edition, pages
MDPI AG, 2018
Keywords
Deformable sensor, Framework, Hexagonal, HoG, Penrose, Pixel form, Sensor grid, Deformation, Image sensors, Pixels, Histogram of gradients, Sensor arrangements, Sensor configurations, Sensor grids, Specific distribution, Anchors
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering Other Computer and Information Science
Identifiers
urn:nbn:se:bth-16631 (URN)10.3390/s18061856 (DOI)000436774300190 ()2-s2.0-85048303219 (Scopus ID)
Note

open access

Available from: 2018-06-27 Created: 2018-06-27 Last updated: 2018-08-21Bibliographically approved
Wen, W. & Siamak, K. (2017). Estimation of Image Sensor Fill Factor Using a Single Arbitrary Image. Sensors, 17(3), 620
Open this publication in new window or tab >>Estimation of Image Sensor Fill Factor Using a Single Arbitrary Image
2017 (English)In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 17, no 3, p. 620-Article in journal (Refereed) Published
Abstract [en]

Achieving a high fill factor is a bottleneck problem for capturing high-quality images. There are hardware and software solutions to overcome this problem. In the solutions, the fill factor is known. However, this is an industrial secrecy by most image sensor manufacturers due to its direct effect on the assessment of the sensor quality. In this paper, we propose a method to estimate the fill factor of a camera sensor from an arbitrary single image. The virtual response function of the imaging process and sensor irradiance are estimated from the generation of virtual images. Then the global intensity values of the virtual images are obtained, which are the result of fusing the virtual images into a single, high dynamic range radiance map. A non-linear function is inferred from the original and global intensity values of the virtual images. The fill factor is estimated by the conditional minimum of the inferred function. The method is verified using images of two datasets. The results show that our method estimates the fill factor correctly with significant stability and accuracy from one single arbitrary image according to the low standard deviation of the estimated fill factors from each of images and for each camera.

Place, publisher, year, edition, pages
MDPI, 2017
Keywords
fill factor; virtual image; image sensor; pipeline; virtual response function; sensor irradiance
National Category
Computer Vision and Robotics (Autonomous Systems)
Identifiers
urn:nbn:se:bth-14046 (URN)10.3390/s17030620 (DOI)000398818700193 ()
Note

open access

Available from: 2017-03-24 Created: 2017-03-24 Last updated: 2018-01-13Bibliographically approved
Zhao, J. & Wen, W. (2017). Image Quality Assessment of Enriched Tonal Levels Images. In: Yao Zhao, Xiangwei Kong, David Taubman (Ed.), Yao Zhao, Xiangwei Kong, David Taubman (Ed.), Image and Graphics 9th International Conference, ICIG 2017, Shanghai, China, September 13-15, 2017, Revised Selected Papers, Part II: . Paper presented at 9th International Conference on Image and Graphics, Shanghai (pp. 134-146). Springer
Open this publication in new window or tab >>Image Quality Assessment of Enriched Tonal Levels Images
2017 (English)In: Image and Graphics 9th International Conference, ICIG 2017, Shanghai, China, September 13-15, 2017, Revised Selected Papers, Part II / [ed] Yao Zhao, Xiangwei Kong, David Taubman, Springer, 2017, p. 134-146Conference paper, Published paper (Refereed)
Abstract [en]

The quality assessment of a high dynamic image is a challenging task. The few available no reference image quality methods for high dynamic range images are generally in evaluation stage. The most available image quality assessment methods are designed to assess low dynamic range images. In the paper, we show the assessment of high dynamic range images which are generated by utilizing a virtually flexible fill factor on the sensor images. We present a new method in the assessment process and evaluate the amount of improvement of the generated high dynamic images in comparison to original ones. The results show that the generated images not only have more number of tonal levels in comparison to original ones but also the dynamic range of images have significantly increased due to the measurable improvement values.

Place, publisher, year, edition, pages
Springer, 2017
Keywords
Image quality assessment, High dynamic range image, Tonal levels, Tone mapping, Fill factor
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-15709 (URN)10.1007/978-3-319-71598-8_13 (DOI)978-3-319-71597-1 (ISBN)
Conference
9th International Conference on Image and Graphics, Shanghai
Available from: 2018-01-02 Created: 2018-01-02 Last updated: 2018-01-03Bibliographically approved
Wen, W. & Khatibi, S. (2016). Back to basics: Towards novel computation and arrangement of spatial sensory in images. Acta Polytechnica, 56(5), 409-416
Open this publication in new window or tab >>Back to basics: Towards novel computation and arrangement of spatial sensory in images
2016 (English)In: Acta Polytechnica, ISSN 1210-2709, Vol. 56, no 5, p. 409-416Article in journal (Refereed) Published
Abstract [en]

The current camera has made a huge progress in the sensor resolution and the low-luminance performance. However, we are still far from having an optimal camera as powerful as our eye is. The study of the evolution process of our visual system indicates attention to two major issues: the form and the density of the sensor. High contrast and optimal sampling properties of our visual spatial arrangement are related directly to the densely hexagonal form. In this paper, we propose a novel software-based method to create images on a compact dense hexagonal grid, derived from a simulated square sensor array by a virtual increase of the fill factor and a half a pixel shifting. After that, the orbit functions are proposed for a hexagonal image processing. The results show it is possible to achieve image processing operations in the orbit domain and the generated hexagonal images are superior, in detection of curvature edges, to the square images. We believe that the orbit domain image processing has a great potential to be the standard processing for hexagonal images.

Place, publisher, year, edition, pages
CZECH TECHNICAL UNIV PRAGUE, 2016
Keywords
Convolution, Fill factor, Hexagonal pixel, Hexagonal processing, Hexagonal sensor array, Orbit functions, Orbit transform, Square pixel
National Category
Other Computer and Information Science
Identifiers
urn:nbn:se:bth-13798 (URN)10.14311/AP.2016.56.0409 (DOI)000411584300010 ()2-s2.0-85008440583 (Scopus ID)
Note

open access

Available from: 2017-01-20 Created: 2017-01-20 Last updated: 2018-01-13Bibliographically approved
Wen, W. & Khatibi, S. (2016). Towards Measuring of Depth Perception from Monocular Shadow Technique with Application in a Classical Painting. Paper presented at International Conference on Computer and Electrical Engineering (ICCEE), Paris. Journal of Computers, 11, 310-319
Open this publication in new window or tab >>Towards Measuring of Depth Perception from Monocular Shadow Technique with Application in a Classical Painting
2016 (English)In: Journal of Computers, ISSN 1796-203X, Vol. 11, p. 310-319Article in journal (Refereed) Published
Abstract [en]

Depth perception is one of important abilities of the human visual system to perceive the three dimensional world. Shadow technique that offers different depth information from different viewing points, known as Da Vinci stereopsis, has been used in classical paintings. In this paper, we report a method towards measuring the relative depth information stimulated by Da Vinci stereopsis in a classical painting. We set up a positioning array of cameras for capturing images from the portrait using a high resolution camera, where the changes of shadow areas are measured by featuring the effects as point and line changes. The result shows that 3D effects of the classical painting are not only a perceptual phenomenon but they are also physically tangible and can be measured. We confirm validity of the method by its implementation even on a typical single image and comparison of results between the single image and the portrait.

Place, publisher, year, edition, pages
Oulo, Finland: Academic Publications, 2016
Keywords
Depth Perception, Da Vinci stereopsis, pictorial cues, classic painting, shadow technique
National Category
Computer Vision and Robotics (Autonomous Systems)
Identifiers
urn:nbn:se:bth-11168 (URN)000378258000005 ()
Conference
International Conference on Computer and Electrical Engineering (ICCEE), Paris
Available from: 2015-12-10 Created: 2015-12-10 Last updated: 2018-01-10Bibliographically approved
Wen, W. & Khatibi, S. (2015). A Software Method to Extend Tonal Levels and Widen Tonal Range of CCD Sensor Images. In: 2015 9TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS): . Paper presented at 9th International Conference on Signal Processing and Communication Systems (ICSPCS), DEC 14-16, 2015, Cairns, AUSTRALIA. IEEE Communications Society
Open this publication in new window or tab >>A Software Method to Extend Tonal Levels and Widen Tonal Range of CCD Sensor Images
2015 (English)In: 2015 9TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS), IEEE Communications Society, 2015Conference paper, Published paper (Refereed)
Abstract [en]

As one of important outcomes of the past decades of researches on sensor arrays for digital cameras, the manufacturers of sensor array technology have responded to the necessity and importance of obtaining an optimal fill factor, which has great impact on collection of incident photons on the sensor, with hardware solution e.g. by introducing microlenses. However it is still impossible to make a fill factor of 100% due to the physical limitations in practical development and manufacturing of digital camera. This has been a bottle neck problem for improving dynamic range and tonal levels for digital cameras e.g. CCD cameras. In this paper we propose a software method to not only widen the recordable dynamic range of a captured image by a CCD camera but also extend its tonal levels. In the method we estimate the fill factor and by a resampling process a virtual fill factor of 100% is achieved where a CCD image is rearranged to a new grid of virtual subpixels. A statistical framework including local learning model and Bayesian inference is used for estimating new sub-pixel intensity values. The highest probability of sub-pixels intensity values in each resampled pixel area is used to estimate the pixel intensity values of the new image. The results show that in comparison to the methods of histogram equalization and image contrast enhancement, which are generally used for improving the displayable dynamic range on only one image, the tonal levels and dynamic range of the image is extended and widen significantly and respectively.

Place, publisher, year, edition, pages
IEEE Communications Society, 2015
Keywords
CCD sensor, tonal range, fill factor, quantum efficiency
National Category
Communication Systems
Identifiers
urn:nbn:se:bth-12967 (URN)000380405700050 ()978-1-4673-8118-5 (ISBN)
External cooperation:
Conference
9th International Conference on Signal Processing and Communication Systems (ICSPCS), DEC 14-16, 2015, Cairns, AUSTRALIA
Available from: 2016-08-31 Created: 2016-08-30 Last updated: 2016-09-20Bibliographically approved
Wen, W. & Khatibi, S. (2015). Novel Software-based Method to Widen Dynamic Range of CCD Sensor Images. In: Yu-Jin Zhang (Ed.), : . Paper presented at International Conference on Image and Graphics 2015, Tianjin, China (pp. 572-583). Springer, 9218
Open this publication in new window or tab >>Novel Software-based Method to Widen Dynamic Range of CCD Sensor Images
2015 (English)In: / [ed] Yu-Jin Zhang, Springer, 2015, Vol. 9218, p. 572-583Conference paper, Published paper (Refereed)
Abstract [en]

In the past twenty years, CCD sensor has made huge progress in improving resolution and low-light performance by hardware. However due to physical limits of the sensor design and fabrication, fill factor has become the bottle neck for improving quantum efficiency of CCD sensor to widen dynamic range of images. In this paper we propose a novel software-based method to widen dynamic range, by virtual increase of fill factor achieved by a resampling process. The CCD images are rearranged to a new grid of virtual pixels com-posed by subpixels. A statistical framework consisting of local learning model and Bayesian inference is used to estimate new subpixel intensity. By knowing the different fill factors, CCD images were obtained. Then new resampled images were computed, and compared to the respective CCD and optical image. The results show that the proposed method is possible to widen significantly the recordable dynamic range of CCD images and increase fill factor to 100 % virtually.

Place, publisher, year, edition, pages
Springer, 2015
Series
Lecture Notes in Computer Science, ISSN 0302-9743
Keywords
Dynamic range, Fill factor, CCD sensors, Sensitive area, Quantum efficiency
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-11169 (URN)10.1007/978-3-319-21963-9_53 (DOI)978-3-319-21963-9 (ISBN)
Conference
International Conference on Image and Graphics 2015, Tianjin, China
Available from: 2015-12-11 Created: 2015-12-11 Last updated: 2017-01-10Bibliographically approved
Hagelbäck, J., Hilborn, O., Jercic, P., Johansson, S., Lindley, C., Svensson, J. & Wen, W. (2014). Psychophysiological Interaction and Empathic Cognition for Human-Robot Cooperative Work (PsyIntEC). In: Rohrbein, F.; Veiga, G.; Natale, C. (Ed.), Gearing Up and Accelerating Cross-Fertilization between Academic and Industrial Robotics Research in Europe: Technology Transfer Experiments from the ECHORD Project (pp. 283-299). Springer
Open this publication in new window or tab >>Psychophysiological Interaction and Empathic Cognition for Human-Robot Cooperative Work (PsyIntEC)
Show others...
2014 (English)In: Gearing Up and Accelerating Cross-Fertilization between Academic and Industrial Robotics Research in Europe: Technology Transfer Experiments from the ECHORD Project / [ed] Rohrbein, F.; Veiga, G.; Natale, C., Springer , 2014, p. 283-299Chapter in book (Refereed)
Abstract [en]

The aim of the PsyIntEC project is to explore affective and cognitive modeling of humans in human-robot interaction (HRI) as a basis for behavioral adaptation. To achieve this we have explored human affective perception of relevant modalities in human-human and human-robot interaction on a collaborative problem-solving task using psychophysiological measurements. The experiments conducted have given us valuable insight into the communicational and affective queues interplaying in such interactions from the human perspective. The results indicate that there is an increase in both positive and negative emotions when interacting with robots compared to interacting with another human or solving the task alone, but detailed analysis on shorter time segments is required for the results from all sensors to be conclusive and significant.

Place, publisher, year, edition, pages
Springer, 2014
Keywords
human-robot interaction, psychophysiology, affective modeling, robotics
National Category
Human Aspects of ICT Computer Sciences
Identifiers
urn:nbn:se:bth-6590 (URN)10.1007/978-3-319-02934-4_14 (DOI)000329752400016 ()oai:bth.se:forskinfoB5643A721B059E9AC1257D6D0036DE33 (Local ID)978-3-319-02933-7 (ISBN)oai:bth.se:forskinfoB5643A721B059E9AC1257D6D0036DE33 (Archive number)oai:bth.se:forskinfoB5643A721B059E9AC1257D6D0036DE33 (OAI)
Available from: 2014-10-10 Created: 2014-10-10 Last updated: 2018-01-11Bibliographically approved
Organisations

Search in DiVA

Show all publications