Examensarbete LITH-ITN-MT-EX--07/005--SE Perceptual depth cue evaluation on an autostereoscopic display Jens Jönsson 2007-02-05 Department of Science and Technology Institutionen för teknik och naturvetenskap Linköpings Universitet Linköpings Universitet SE-601 74 Norrköping, Sweden 601 74 Norrköping LITH-ITN-MT-EX--07/005--SE Perceptual depth cue evaluation on an autostereoscopic display Examensarbete utfört i medieteknik vid Linköpings Tekniska Högskola, Campus Norrköping Jens Jönsson Handledare Thomas Ericson Examinator Matt Cooper Norrköping 2007-02-05 Datum Avdelning, Institution Date Division, Department Institutionen för teknik och naturvetenskap 2007-02-05 Department of Science and Technology Språk Rapporttyp ISBN Language Report category _____________________________________________________ Svenska/Swedish Examensarbete ISRN LITH-ITN-MT-EX--07/005--SE x Engelska/English B-uppsats _________________________________________________________________ C-uppsats Serietitel och serienummer ISSN x D-uppsats Title of series, numbering ___________________________________ _ ________________ _ ________________ URL för elektronisk version Titel Title Perceptual depth cue evaluation on an autostereoscopic display Författare Author Jens Jönsson Sammanfattning Abstract In this work an application for evaluating different 3D displays is developed. The work is carried out in collaboration with Setred AB that develops an autostereoscopic display. A stereoscopic display lets the user see different perspectives of a scene with each eye. A presentation of previous research within depth perception and stereoscopic 3D displays is made. Based on results from previous evaluations, a test environment is designed. It is implemented in C++ and OpenGL and a small Interface Library is developed. A couple of test sessions are carried out with a relative small number of subjects to provide results for an evaluation of the test environment. Results from the evaluation are used in combination with previous research to conclude the design of an evaluation environment. Tracking 3D paths is suggested as a suitable task for evaluating 3D displays. Three types of parameters are suggested for use as dependent variables: response time, rate of correct answers and accuracy. The parameters are used in the evaluation environment developed. One test developed intends to give an appreciation of how small differences in depth that are noticeable on the display. No distinct value for the depth resolution is found. In a scene influence test, the task is to position three objects in specific places on the walls of a room. For this test the accuracy is measured and used as the dependent variable. The presence of a reference structure improves the result in this test. Two different tests are carried out to evaluate occlusion. A number of tiles are to be ordered in increasing depth and the error rate of the ordering is used as dependent variable in this test. The results from the two tests indicate that occlusion overrides binocular disparity. A user interaction test that requires movement in three dimensions is developed. It evaluates six different methods to do this. The keyboard interaction method is preferred by some of Nyckelord Keyword autostereoscopic, depth perception, display systems, evaluation Upphovsrätt Detta dokument hålls tillgängligt på Internet – eller dess framtida ersättare – under en längre tid från publiceringsdatum under förutsättning att inga extra- ordinära omständigheter uppstår. Tillgång till dokumentet innebär tillstånd för var och en att läsa, ladda ner, skriva ut enstaka kopior för enskilt bruk och att använda det oförändrat för ickekommersiell forskning och för undervisning. Överföring av upphovsrätten vid en senare tidpunkt kan inte upphäva detta tillstånd. All annan användning av dokumentet kräver upphovsmannens medgivande. För att garantera äktheten, säkerheten och tillgängligheten finns det lösningar av teknisk och administrativ art. 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All other uses of the document are conditional on the consent of the copyright owner. The publisher has taken technical and administrative measures to assure authenticity, security and accessibility. According to intellectual property law the author has the right to be mentioned when his/her work is accessed as described above and to be protected against infringement. For additional information about the Linköping University Electronic Press and its procedures for publication and for assurance of document integrity, please refer to its WWW home page: http://www.ep.liu.se/ © Jens Jönsson Perceptual depth cue evaluation on an autostereoscopic display Thesis work for the degree of Master of Science Examensarbete Civilingenjör Medieteknik Jens Jönsson Examiner: Matt Cooper, [email protected] Supervisor: Thomas Ericson, [email protected] (Setred AB) Abstract Keywords: autostereoscopic, depth perception, display systems, evaluation. In this work an application for evaluating different 3D displays is developed. The work is carried out in collaboration with Setred AB that develops an autostereoscopic display. A stereoscopic display lets the user see different perspectives of a scene with each eye. A presentation of previous research within depth perception and stereoscopic 3D displays is made. Based on results from previous evaluations, a test environment is designed. It is implemented in C++ and OpenGL and a small Interface Library is developed. A couple of test sessions are carried out with a relative small number of subjects to provide results for an evaluation of the test environment. Results from the evaluation are used in combination with previous research to conclude the design of an evaluation environment. Tracking 3D paths is suggested as a suitable task for evaluating 3D displays. Three types of parameters are suggested for use as dependent variables: response time, rate of correct answers and accuracy. The parameters are used in the evaluation environment developed. One test developed intends to give an appreciation of how small differences in depth that are noticeable on the display. No distinct value for the depth resolution is found. In a scene influence test, the task is to position three objects in specific places on the walls of a room. For this test the accuracy is measured and used as the dependent variable. The presence of a reference structure improves the result in this test. Two different tests are carried out to evaluate occlusion. A number of tiles are to be ordered in increasing depth and the error rate of the ordering is used as dependent variable in this test. The results from the two tests indicate that occlusion overrides binocular disparity. A user interaction test that requires movement in three dimensions is developed. It evaluates six different methods to do this. The keyboard interaction method is preferred by some of the test subjects and provides the best results. Index 1 Introduction...................................................................................................1 1.1 Setred AB ...............................................................................................2 1.2 Aims and method....................................................................................2 1.3 Outline of this thesis report .....................................................................3 2 Perceptual depth cues.....................................................................................4 2.1 Depth cue theory.....................................................................................4 2.1.1 Psychological depth cues..................................................................5 2.1.2 Physiological depth cues ..................................................................8 2.2 Combining cues ....................................................................................10 2.2.1 Cue interaction models...................................................................10 2.2.2 The relative importance of different cues........................................11 2.3 Different types of tasks and scenes........................................................13 2.4 Conclusion............................................................................................14 3 The display system ......................................................................................16 3.1 Autostereoscopic displays .....................................................................16 3.1.1 Lenticular sheet displays ................................................................17 3.1.2 Multiple projector systems .............................................................17