Package compiled for FAA managers

Federal Agencies Digitization Initiative Still Image Working Group - August 2010
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Part II - Evaluation and Quality Control of Digital Imaging
- SIGNAL-
OECF - Opto Electronic Conversion Function (ISO 14545)
TIF - Tone Transfer Function
TRC - Tone Reproduction Curve
definition: Average large area digital response of an electronic imaging device to light stimuli
Sensitivitv Tone aod ExRQsure White Balance[Neutralitx'. Color EocodiogLReoderiog
(ISO 12232) definition : characteristic behavior of definition : equivalence of large area Accuracy
definition: The reciprocal of the large area di9itat output response color channel output respanses to a f1ef/nltion: The dllference between selectl!d
amount or light necessary to ( count value) to spectrally neutral range of spectrally neutral input stimuli physically measured input cO:Ors and their
achieve a desired output input stimuli ( gray patch) Intended output rendering rrom a given color
response. space.
- Responsivity - Too dar1</light - Color cast - Over/under sallJratl!d colors
- Speed - Under/over eicposed - Gray balance - Color balance Is wrong
- Exposure Index (EI) - No shadow/highlight detail - Memory colors are not correct
- Olpplng - Color /la:Jracy
- Contrast - Color Saturation
- Exposure N:oJracy
e:Saturation based speed e:Average, median, maximum or e:Average, median, maximum, or RMS
RMS deviation from aim for neutral deviation from aim for dlromatic patches of
units: T8D patx:hes of lntl!rest. e:AveraQe, median, maximum, or Interest
lVIJIS': Count Values, t:J..•, Den sity, f. RMS deviation from aim between color
stops channels ( R-G, R·B, G·B ) for neutral Units{• ): Coont Values, Delta E (ll.E ), Delta
w : Noise based speed w : Deviation from a reference OECF patches or lntl!rest. E (llEa•b•),
units: 780 gamma value Units r• J: Count Values, llEa•b• I Units{• ): Delta C, Delta H
0 : Exposure Index, Standard units: gamma ( unitless) Units ( • ) : Delta C, Delta H
Output Sensllivlty
• Jneffident Imaging detector - Auto-contrast failures - Poor auto-white balance algorithm - Color profile tweaked for preference
- Inappropriate blad</whlte point - Bad white / blade point calibration - Wrong oolor profile intent
calibration. - Sparse gray paten balancing - Wrong COior profile dlosentembedded
- Wrona gamma selection or tone aim - Color Balance - Cnlnr pmfila ;l~ mp tioM l rw:o~~M t with
- Strongly COiored environmental pradloo (I.e. lighting quarity, gamma,
surround Intent, etc.)
- Environmental : highly dlromatic oolor
surround/dothlng
Techni cal Guidelines for Digitizing Cultural Heritage Materials: Creation of Raster Image Master Files 9
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