CONTENTS 1. Introduction 1.1 Course Outline 1 1.2 Introduction ...

Introduction to image quality. The image quality circle. Visual performance of imaging systems.
Introduction to psychophysics.
Image Quality Metrics. The observer's function, methods of determination, influence of noise, scaling
methods and statistics.
Image quality measurement in image processing and image compression. Digital image artefacts
Performance criteria, distortion metrics.
Set-up for psychophysical experiments. Characterisation and calibration of viewing conditions and
output devices. Theory and implementation of psychophysical tests.
Paired Comparisons. Types of paired comparison tests. Software. Numbers of observers. Analysis of
data, Errors.
Evaluation of thresholds. Measurement of fidelity. Just-noticeable-differences: image attributes &
image quality. Data analysis. ‘The image quality ruler’.
Scene Dependency in image quality. Scene selection. Scene content. Influence on image quality
judgements.
Image analysis. Measurement of scene characteristics. Incorporation in image quality studies/metrics.
Teaching and Learning Methods:
The module comprises lectures and seminars and supervised workshops and laboratory sessions.
Assessment Rationale:
The module is concerned with the objective and subjective evaluation of images. The written
coursework is designed to support the learning process and to aid in the understanding of some
challenging concepts, 40% (Learning outcomes 1-4).
Self-directed practical work is designed to give the student experience in setting up and analysing the
results from both subjective and objective evaluations, 60%. This will test learning outcomes 1-5.
Assessment Criteria:
The extent to which the student is able to demonstrate the ability to:
• Interpret the terminology relevant to imaging performance and image quality.
• Use appropriate formulae from theory to analyse data and interpret findings.
• Understand models for image quality metrics.
• Plan, carry out and report on experimental investigations.
• Comment critically on results obtained, with due regard for experimental errors and the
significance of the result.
• Use research/reference literature as appropriate.
Assessment Methods and Weightings:
Written Coursework 40%
Laboratory Work 60%
Written Coursework may consist of an essay and a number of problems requiring a detailed and
accurate analysis with justifications and appropriate assumptions. Some computer modelling may be
required. Laboratory work is assessed by written reports from practical assignments.
The student must demonstrate the ability to:
• Understand and interpret an experimental brief and establish the appropriate experimental design.
• Undertake reliable collection of data using suitable instrumentation.
• Analyze the data in an accurate manner, and clearly present the relevant results.
• Present sound discussions and conclusions on the work, in the light of other published results or
expected outcomes.
Sources:
Essential reading
C.N.Proudfoot (ed.) (1973) SPSE Handbook of Photographic Science and Engineering, 2 nd Ed., IS&T,
Springfield, USA.
J.C.Dainty and R.Shaw (1974) Image Science, Academic Press, London, England.
DPI_Hbook 80 ©University of Westminster