pqs recommendation-sensory-experience

RECOMMENDATIONS FOR THE SUBJECTIVE EVALUATION OF SENSORY EXPERIENCE

Benjamin Rainer, Christian Timmerer, and Markus Waltl

TABLE OF CONTENTS Introduction

Motivation

Test Setup

Single Stimulus Studies SSCQE + ACR

Double Stimulus Studies DCR DSCQS + single stimulus

INTRODUCTION• Multimedia enriched by sensory effects like wind, vibration

and light For quality degradations by lowering the bitrate of the actual video sequence For genres like action, documentary, commercial, and sports Intensity of emotions are influenced

• Passive emotions are decreased• Active emotions are increased

MOTIVATION

How has the test setup and design to be, for subjectively assessing the QoE of sensory experience?

Which stimulus methods are useful for subjectively assessing sensory experience? Single stimulus? Double stimulus?

Does mixing up single stimulus and double stimulus end up in a bias when assessing sensory experience?

TEST CONDITIONS, TEST SETUP, AND TEST DESGIN

In-Lab assessments Setup according to ITU-R BT.500-11/13 Ergonomic placement of keyboard, mouse and seat

Test setup

TEST CONDITIONS, TEST SETUP, AND TEST DESGIN

Textual introduction Each participant is presented the same introduction

Allows for training phases Includes demographic questions aswell as the possiblity for the

participants to give feedback Supports different test methods

SINGLE STIMULUS EVALUATION - SSCQE + ACR

Single Stimulus Continuous Quality Evaluation with categorical rating scale Combined with an Absolute Category Rating (ACR)


24 Participants 11 female 13 male

Assess whether sensory effects unmask quality degradations Quality in terms of bitrate

Dedicated voting device Stressed the participants for the SSCQE part No intiuitive handling of the voting device More intuitive voting devices should be used

• Indirect devices e.g., EEG

Assessing Sensory Experience with SSCQE is not recommended


Earth Sequence Babylon A.D. Sequence

DOUBLE STIMULUS EVALUATIONS - DCR

Degradation Category Rating Double stimulus with a categorical scale

• very annoying (1), annoying (2), imperceptible (3), little enhancement (4) and big enhancement (5)

Assess the enhancement of sensory effects

No randomization of reference and test condition Reference can be easily identified (no effects)

25 Participants 12 female 13 male

DOUBLE STIMULUS EVALUATIONS - DCR

DOUBLE STIMULUS EVALUATIONS - DSCQS

Double Stimulus Continuous Quality Scale Modified by combining it with a single stimulus

• After each stimulus presentation emotion rating• Double stimulus for the enhancement of QoE

The rating scale for emotions and the enhancement in QoE was on an interval of [0,100]


In total 68 participants 36 female 32 male

Conducted at three sites AAU (Austria) UOW (Australia) RMIT (Australia)

For identyfing a bias of the combined test method studies from UOW and RMIT were used


No significant difference between the means of RMIT and UoW

CONCLUSIONS

Single stimulus method with categorical rating scales are suitable for assessing the sensory experience

SSCQE may stress the participants, the voting device plays an important role Even with an intuitive voting device particpants may be

stressed due to effects and the task of the continuous voting

Indirect voting devices such as EEG should be used

CONCLUSIONS

The DSCQS was modified to fit the needs of an subjective quality evaluation in the domain of sensory experience

The DCR method was used as defined, only the rating scale had to be changed slightly (from impairment to enhancement)

When combining stimulus methods caution is advised that no bias is introduced

THANK YOU!

QA

pqs recommendation-sensory-experience

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