Image Naming Conventions - Photography - Beneath the Waves

Image Naming Conventions

article by Ben Lincoln

General Abbreviations

Abbreviation	Meaning	For Further Information
3C	A "three-channel" image - one in which three greyscale images are mapped to red, green, and blue.	Three-Channel False Colour
B	Blue. Note that this may have several different definitions in terms of spectral range depending on the context.	A Detailed Introduction
DCS	A "decorrelation-stretch" image - a colour image processed using a complex mathematical technique to reveal hidden details.	Decorrelation Stretch Images
DCS EC	"DCS-enhanced contrast". An technique I've experimented with off and on to combine the contrast-enhancement of DCS images with less-overpowering colours from the original image. I consider it unsuccessful at this time, but will include examples if they appear interesting.	Decorrelation Stretch Images
FC	"False colour". The use of colour in an image that differs significantly from how the subject would appear to human eyes.	A Detailed Introduction
G	Green. Note that this may have several different definitions in terms of spectral range depending on the context.	A Detailed Introduction
Gr	A gradient-based image - one in which a colour palette is mapped onto a greyscale image.	Gradient-Mapped False Colour Images
Grey or GS	A greyscale ("black-and-white") image.	Basic Greyscale Images
LC or L/C	A "luminance/colour" image - one in which a colour image is overlaid on top of a greyscale image.	Luminance/Colour Images
NIR	Near infrared - the spectral range from about 700nm to about 1400nm. The equipment I use is most sensitive to about 700nm - 1000nm.	A Detailed Introduction
R	Red. Note that this may have several different definitions in terms of spectral range depending on the context.	A Detailed Introduction
Tn	A greyscale image which has been tinted using a particular colour.	Luminance/Colour Images
UVA	Ultraviolet-A - the spectral range from about 300nm to about 400nm. The equipment I use is sensitive from about 350nm to about 400nm.	A Detailed Introduction
V	Violet. This term is used in the scientific sense of representing the shortest-wavelength light that human eyes can generally see, as opposed to its common definition of being synonymous with "purple".	A Detailed Introduction

Mathematical and Statistical Terms and Abbreviations

Abbreviation	Meaning	For Further Information
AbsDiff or Absolute Difference	The difference between two values, with negative values multiplied by -1 to make them positive.	Calculated Greyscale Images
ADev or Average Deviation	A statistical calculation intended to provide a value indicating how much variation there is among values in a set.	Statistical Greyscale Images
Avg or Average	A statistical calculation intended to provide a value indicating the "middle" of a set of values.	Statistical Greyscale Images
Kurt or Kurtosis	A statistical calculation intended to provide a value indicating how biased a set of values is.	Statistical Greyscale Images
Max or Maximum	The highest value out of a set.	Statistical Greyscale Images
Med or Median	A statistical calculation intended to provide a value indicating the "middle" of a set of values.	Statistical Greyscale Images
Min or Minimum	The lowest value out of a set.	Statistical Greyscale Images
ND or Normalized Difference	The result of the function x = (a-b)/(a+b). "Pos"/"Positive" and "Neg"/"Negative" variations mean that the results have been limited to only positive or negative values (respectively).	Calculated Greyscale Images
Rng or Range	The maximum value out of a set minus the minimum value from the same set.	Statistical Greyscale Images
Skew or Skewness	A statistical calculation intended to provide a value indicating how biased a set of values is.	Statistical Greyscale Images
SDev or Standard Deviation	A statistical calculation intended to provide a value indicating how much variation there is among values in a set.	Statistical Greyscale Images
Var or Variance	A statistical calculation intended to provide a value indicating how much variation there is among values in a set.	Statistical Greyscale Images

Simple ("First-Order") Image Name Examples

Name	Meaning	For Further Information
G - B - UVA [3C]	A three-channel image in which near green, blue, and ultraviolet-A have been mapped to red, green, and blue respectively.	Three-Channel False Colour
NIR - R - G [3C]	A three-channel image in which near infrared, red, and green have been mapped to red, green, and blue respectively.	Three-Channel False Colour
NIR - 87C Grey [Tinted]	The greyscale version of a near infrared image, tinted using the colour "87C Grey" (named for the subtle colouration of unprocessed NIR images when I use a Kodak Wratten 87C-style filter (B+W 093, etc.).	Luminance/Colour Images
R - G - B [3C]	A three-channel image in which the colours represent (more or less) that way the scene would appear to your own eyes.	Three-Channel False Colour

Complex ("Higher-Order") Image Name Examples

Name	Meaning	For Further Information
All Bands (ADev) Luminance - (Calculated: (Ratio: R To NIR) - (Ratio: G To R) - (Ratio: UVA To G)) Colour [L/C]	A luminance/colour image. The luminance (similar to the brightness) is the average deviation across the entire image cube (for each pixel). On top of this are mapped the colours of the three-channel image created by using three different ratio-based images to create a three-channel colour image.	Statistical Greyscale Images, Three-Channel False Colour, Luminance/Colour Images
All Bands (Kurt) Luminance - ((Calculated: ASVI (Full Range)) - Vegetation Index Triple Scale 4) Colour [L/C]	A luminance/colour image. The luminance is the kurtosis across the entire image cube (for each pixel). On top of this are mapped the colours of the image created by mapping the "vegetation index triple scale 4" gradient to the atmosphere and soil resistant vegetation index calculated greyscale image.	Calculated Greyscale Images, Statistical Greyscale Images, Gradient-Mapped False Colour Images, Luminance/Colour Images
All Bands (Max) - All Bands (Med) - All Bands (Min) [3C]	A three-channel image in which the red channel represents the maximum value out of the entire image cube (for that pixel), the green channel represents the median value out of the entire image cube, and the blue channel represents the minimum value out of the entire image cube.	Statistical Greyscale Images, Three-Channel False Colour
(All Bands (Max) - All Bands (Med) - All Bands (Min)) - RDCS: (YUV - 25 Percent)	A decorrelation-stretch image created out of the previous three-channel image. In this case, a "running DCS" was performed in the YUV colourspace, with the image being subdivided into quarters.	Statistical Greyscale Images, Three-Channel False Colour, Decorrelation Stretch Images
Calculated: (Difference: R - G) - (Difference: G - B) - (Difference: B - UVA) [3C]	A three-channel image in which the red channel represents the difference between the original red and green exposures, the green channel represents the difference between the original green and blue exposures, and the blue channel represents the difference between the original blue and ultraviolet-A exposures.	Calculated Greyscale Images, Three-Channel False Colour
Calculated: (Ratio: UVA To NIR) - (Ratio: UVA To R) - (Ratio: UVA To G) [3C]	A three-channel image in which the red channel represents the ratio of the original ultraviolet-A to near infrared exposures (the result of dividing the former by the latter), the green channel represents the ratio of the original ultraviolet-A to red exposures, and the blue channel represents the ratio of the original ultraviolet-A to green exposures.	Calculated Greyscale Images, Three-Channel False Colour
NIR Luminance - (UVA - Neon Pink) Colour [L/C]	A luminance/colour image created by using the near infrared exposure as the luminance, and the neon pink-tinted version of the ultraviolet-A exposure as the colour laid on top.	Calculated Greyscale Images, Three-Channel False Colour
(R - G - B) - DCS	A decorrelation-stretch image created out of the R-G-B (standard colour) image.	Three-Channel False Colour, Decorrelation Stretch Images
Statistical: All Bands (ADev) - All Bands (Var) - All Bands (Range) [3C]	A three channel image in which the red channel represents the average deviation (on a per-pixel basis) across the entire image cube, the green channel represents the variance across the entire image cube, and the blue channel represents the range across the entire image cube.	Statistical Greyscale Images, Three-Channel False Colour

Custom Image Image Name Examples

Name	Meaning	For Further Information
Custom: AGB VisNBC DiffVariation4 [3C]	An image generated using a particular variation of Andrea G. Blum's false colour technique.	TMSB Tutorial 4C: Andrea G. Blum Colour Combination XML File
Custom: Green 11 Exaggerated [3C]	An image intended to simulate the appearance of the scene had it been shot using a modified Nikon D70 equipped with a #11 green filter, with the effect deliberately exaggerated.	False Colour From Filters (and Simulated Filters)
Custom: R72 Classic [3C]	An image intended to simulate the appearance of the scene had it been shot using an old-style digital camera (around 2000-vintage) equipped with a Hoya R72 or other red/IR-longpass filter.	False Colour From Filters (and Simulated Filters)

Related Articles:
A Brief Introduction
A Detailed Introduction
Basic Greyscale Images
Calculated Greyscale Images
Statistical Greyscale Images
Three-Channel False Colour
Gradient-Mapped False Colour Images
Luminance/Colour Images
Decorrelation Stretch Images
False Colour From Filters (and Simulated Filters)
TMSB Tutorial 4C: Andrea G. Blum Colour Combination XML File