CIE Activities related to Image Technology János Schanda CIE VP Techn. Virtual Environments and Imaging Technologies Laboratory University of Pannonia

CIE Division 1 Vision and Colour  TC 1-27: Specification of Colour Appearance for Reflective Media and Self-Luminous Display Comparisons  TC 1-44: Practical Daylight Sources for Colorimetry  TC 1-57: Standards on Colorimetry  TC 1-66: Indoor Daylight Illuminant  TC 1-69: Colour rendition by white light sources  TC 1-70: Metameric Samples for Indoor Daylight Evaluation  TC 1-72: Measurement of Appearance Network

TC 1-27: Specification of Colour Appearance for Reflective Media and Self-Luminous Display Comparisons  ToR: To study and make recommendations for the specification of a colour appearance match between a reflective image and a self-luminous display image.

TC 1-44: Practical Daylight Sources for Colorimetry  1. To intercompare existing daylight sources for colour measuring instruments and colour matching booths.  2. On the basis of this intercomparison, to recommend practical methods for simulating daylight illuminants.

TC 1-57: Standards on Colorimetry  ToR: To prepare and ISO/CIE Standard(s) that describes 1) the method of calculating CIE tristimulus values and chromaticity coordinates 1) the method of calculating CIE tristimulus values and chromaticity coordinates 2) a uniform colour space and its associated metrics and 2) a uniform colour space and its associated metrics and 3) a formula for industrial colour difference evaluation 3) a formula for industrial colour difference evaluation

TC 1-66: Indoor Daylight Illuminant  ToR: To prepare a CIE recommendation on an Indoor Daylight Illuminant and a corresponding Indoor Daylight Source, considering the needs of the partner international organisations

TC 1-66: Indoor Daylight Illuminant  Average external transmission of clear window glass samples for a nominal 10 mm thickness.

TC 1-66: Indoor Daylight Illuminant  Relative spectral power distribution of CIE standard illuminant D65, CIE daylight illuminant D50 and of the recommend ed indoor D50 and D65 illuminants.

TC 1-69: Colour rendition by white light sources  1.)To agree on some basic criteria for a new metric (or system of metrics) such that it (or they) could be developed to be scientifically sound, acceptable to lighting industry, and useful. Colour fidelity Colour fidelity Colour preferemce Colour preferemce Colour discrimination Colour discrimination  2.) To solicit, share, and discuss proposals for new assessment procedures for colour rendition properties of white light sources.

TC 1-69: Colour rendition by white light sources  3.) To evaluate proposed assessment procedures with visual experiments and compatibility with basic criteria (in #1).  4.) To recommend a new metric (or system of metrics) based on evaluation (in #3).  5.) To prepare a CIE Technical Report on recommended new metric (or system of metrics), including calculation procedures and justification for recommendation.

TC 1-70: Metameric Samples for Indoor Daylight Evaluation  To investigate the derivation of a set of metameric samples to enable the evaluation of indoor daylight simulators A continuation of the activities of TC 1-66: Indoor Daylight Illuminant

TC 1-72: Measurement of Appearance Network: MApNet  1.) To establish a network of those interested in the measurement of visual appearance.  2.) The network shall be under the direction and guidance of a group of at least four Technical Leaders each responsible for a particular aspect of the subject.  3.) Each Technical Leader shall provide substantial periodic reports in a form that might be published.

TC 1-72: Measurement of Appearance Network: MApNet  4.) A second Expert Symposium on Appearance shall be organised at an appropriate time within the next 4 years.  5.) A database of relevant published work shall be maintained.  6.) Consideration shall be given to the establishment of separate Technical Committees when appropriate.

CIE Division 2 PHYSICAL MEASUREMENT OF LIGHT AND RADIATION  TC 2-28: Methods of Characterizing Spectrophotometers  TC 2-51: The Calibration of Diode Array Spectrometers  TC 2-59: Characterisation of Imaging Luminance Measurement Devices  TC 2-60: Effect of Instrumental Bandpass Function and Measurement Interval on Spectral Quantities

TC 2-28: Methods of Characterizing Spectrophotometers  Write a CIE report on the characterization of spectrophotometers by means of reference materials and other methods, with particular reference to linearity, wavelength error, stray light, and integrating sphere errors.

TC 2-51: The Calibration of Diode Array Spectrometers  To produce a technical report for the calibration of detector array spectroradiometers  Diode array and CCD spectrometers suffer from: Stray light Stray light Temperature dependence Temperature dependence External fibre cable problems External fibre cable problems

TC 2-59: Characterisation of Imaging Luminance Measurement Devices  To prepare a Technical Report on methods for the characterisation of imaging luminance measurement devices

TC 2-60: Effect of Instrumental Bandpass Function and Measurement Interval on Spectral Quantities  To prepare a Technical Report that describes the effect of instrumental bandpass functions and measurement wavelength interval on spectrally resolved quantities and to provide recommendations on suitable methods to minimise the error introduced by instrumental bandpass functions on spectrally integrated or weighted quantities

CIE Divisions 3 to 6  Division 3: Interior environment and lighting design  Division 4: Lighting and signalling for transport  Division 5: Exterior and other lighting applications  Divsion 6: Photobiology and photochemistry

Division 8: Image technology  CIE D8 publications  TC 8-02: Colour difference evaluation in images  TC 8-07: Multispectral Imaging  TC 8-08: Testing of Spatial Colour Appearance Models  TC 8-09: Archival Colour Imaging  TC 8-10: Office Lighting for Imaging  TC 8-11: CIECAM02 Mathematics  TC 8-12: Video Compression Assessment

CIE D8 publications  A Colour Appearance Model for Colour Management Systems: CIECAM02 by TC8-01 CIE 159:2004  Chromatic Adaptation Under Mixed Illumination Condition When Comparing Softcopy and Hardcopy Images by TC8-04 CIE 162:2004  Criteria for the Evaluation of Extended-Gamut Colour Encodings by TC8-05 CIE 168:2005  Guidelines for the Evaluation of Gamut Mapping Algorithms by TC8-03 CIE 156:2004  The Effects of Fluorescence in the Characterization of Imaging Media by R8-05 CIE 163:2004

CIE 159:2004 A Colour Appearance Model for Colour Management Systems: CIECAM02 by TC8-01  A colour appearance model provides a viewing condition specific method for transforming tristimulus values to and/or from perceptual attribute correlates. This document outlines a specific colour appearance model, CIECAM02, which may be useful for colour management applications. This model is based on CIECAM97s colour appearance model and consists of a chromatic adaptation transform and equations for computing a set of perceptual attribute correlates. The evolution and application of this colour appearance model are presented.

CIE 162:2004 Chromatic Adaptation Under Mixed Illumination Condition When Comparing Softcopy and Hardcopy Images by TC8-04  Users often desire to compare hardcopy and softcopy images using rapid successive binocular observations. The focus of this report is to determine how colour imaging experts can best accommodate the desires and practices of these more casual observers. It shows that accounting for mixed and incomplete chromatic adaptation produces more accurate results in colour appearance than not accounting for them. It includes a mathematical model for chromatic adaptation and provides appropriate parameters for the chromatic adaptation model under such viewing conditions.

CIE 168:2005 Criteria for the Evaluation of Extended- Gamut Colour Encodings by TC8-05  One set of applications that was identified by the committee required the use of extended-gamut colour encodings. This document defines a set of objective metrics for evaluating the characteristics of output-referred extended-gamut colour encodings. Detailed metrics have been developed to evaluate a number of important attributes of extended-gamut colour encodings.

CIE 168:2005 Criteria for the Evaluation of Extended- Gamut Colour Encodings by TC8-05  These criteria include: gamut volume characteristics, gamut volume characteristics, colour quantization characteristics, colour quantization characteristics, hue constancy when applying non-linear tone scale modifications to RGB colour values, hue constancy when applying non-linear tone scale modifications to RGB colour values, complexity of transformation required to and from typical standard spaces (sRGB, ICC PCS, etc.). complexity of transformation required to and from typical standard spaces (sRGB, ICC PCS, etc.).

CIE 168:2005 Criteria for the Evaluation of Extended- Gamut Colour Encodings by TC8-05  The relative importance of the individual metrics will vary on an application-by-application basis. As a result, the committee concluded that the actual evaluation of candidate colour encodings for use in particular applications should be left to other standards bodies that are more closely aligned with the relevant industry segments, and therefore would be better able to define the appropriate application-dependent requirements.

CIE 163:2004 The Effects of Fluorescence in the Characterization of Imaging Media by R8-05  The addition of fluorescence to either the inks or the substrate greatly increases the level of uncertainty in instrumental readings of the optical properties of printed images. CIE "Intercomparison on measurement of (total) spectral radiance factor of luminescent specimens" shows that even research and standards laboratories experience a degradation in their reproducibility of up to one order of magnitude (10x), in the readings of total spectral radiance factor of strongly coloured, fluorescent materials.

CIE 163:2004 The Effects of Fluorescence in the Characterization of Imaging Media by R8-05  This report contains results from a study of the measurement of total spectral radiance factor of digital halftone printing over a range of substrates exhibiting various levels of fluorescence. Colorimetric properties were computed for CIE Illuminant D50 when the UV component was included and when the UV component was excluded from the measurement source.  The results indicate and quantify that the fluorescence of the substrate can be measured in both solid ink areas and halftone ink area with the effect being far larger in the latter.

CIE 163:2004 The Effects of Fluorescence in the Characterization of Imaging Media by R8-05  The magnitude of the CIELAB colour differences indicate that a significant lack of reproducibility may be experienced between two imaging centers who attempt to apply colour management principles to their individual measurements of the same image printed on fluorescent substrates or between two laboratories who attempt to quantify the colour differences between images printed on fluorescent stock and measured using instruments with different sources.

CIE 163:2004 The Effects of Fluorescence in the Characterization of Imaging Media by R8-05  The preliminary reports of CIE TC 1-44 "Practical daylight simulators for colorimetry" have shown that significant variability exists among instruments claiming daylight simulations and an even greater difference between instruments with UV-rich pulsed xenon lamps and those with UV-poor incandescent lamps.

Availability of CIE Publications:  CIE Technical Reports and Standards are available electronically or printed at 

TC 8-02: Colour difference evaluation in images  To study, develop and standardize methods to derive colour differences for images.

TC 8-07: Multispectral Imaging  To study, develop and recommend encoding techniques and data formats for the exchange of multispectral images, and to provide test procedures for the evaluation of multispectral imaging systems  Recent demonstrations at a meeting in Darmstadt

TC 8-08: Testing of Spatial Colour Appearance Models  To design, implement and report the results of a psychophysical test comparing the output of spatial colour appearance models (including Retinex, MOM and iCAM) for high dynamic range still images

TC 8-09: Archival Colour Imaging  To recommend a set of techniques for the accurate capture, encoding and long term preservation of colour descriptions of digital images that are either born digital or the result of digitizing 2D static physical objects including documents, maps, photographic materials and paintings

Some images of cultural heritage  Madonna on the rocks, Louvre. Two artefacts from the same database Two artefacts from the same database  Van Gogh: Bedroom

TC 8-10: Office Lighting for Imaging  To report on the spectral power distribution and illumination levels used to view images in office lighting conditions. The report is to be based on empirical research  Round robin test under way, circulating Box with LEDs to test spectroradiometer Box with LEDs to test spectroradiometer Paper samples of different amount of whitening agent Paper samples of different amount of whitening agent Request of measuring artificial and natural light spectra on Request of measuring artificial and natural light spectra on desk, wall and monitordesk, wall and monitor

TC 8-10: Office Lighting for Imaging: personal questions ScopeData Value Range Individual Identifier Insert users initials and starting date of measurement in ISO format: YYYYMMDD 4 letters&8numbers, stat with Family Name Initial, please! Full name of contact person mailing address: address: Phone: Fax:

TC 8-10: Office Lighting for Imaging, questions on the instrument Per Measurement Device Measurement principle Radiance or irradiance Spectroradiometer brand, model, and configuration For example: XY Model AB spectroradiometer Instrument specifications (if custom): Wavelength range [nm] Wavelength accuracy [nm] Wavelength resolution [nm] Stray light level % Optical Half Bandwidth (FWHM) [nm] (FWHM = convolution of input and exit slit windows) Noise Equivalent radiance/Irradiance Irradiance: watt/m^2 Measurement of LED sources for this study: day of year Calendar Date

TC 8-10: Office Lighting for Imaging, questions on the location Per Office Measurement day of year Calendar Date in ISO format: YYYY-MM-DD Measurement time of day Hour [0000 – 2400] [i.e.., using a 24 hour clock, 6:25 p.m. would be reported as 1825] Measurement geography Country, state, city, street address Unique Office Identifier Office number, name, or other Office Description A-G Lighting Description Lamp position [overhead/task (+type(s) if known)], natural lighting [Y/N]

TC 8-10: Office Lighting for Imaging, Test box and components

TC 8-10: Office Lighting for Imaging, Results on LED measurements

Laboratory White Red xy Tcc, K Ra Lum, cd/m2 xy GreP NexPress Yaguchi Afternoon YY TC8-10SunChem McCarthy

TC 8-10: Reflectance spectra of the three paper samples

TC 8-10 : Example of a field measurement

TC 8-11: CIECAM02 Mathematics  To investigate the improvements of the CIECAM02 model to avoid mathematical inconsistencies  Established in 2007, Chair: Changjun Li

TC 8-12: Video Compression Assessment  To establish and report on the display and viewing conditions and materials for video compression quality evaluation in different applications including, but not limited to, web, mobile phones, HDTV, home cinemea and digital cinema  Established in 2007, Chair: Christine Fernandez-Maloigne

 Thanks for your kind attention!