EXIF Info

ImageDescription
Describes the image

Model
Shows model number of digicam

Orientation The orientation of the camera relative to the scene, when the image was captured

1 top left side
2 top right side
3 bottom right side
4 bottom left side
5 left side top
6 right side top
7 right side bottom
8 left side bottom

Resolution, YResolution
Display/Print resolution of image.
Default value is 1/72inch, but it has no mean because personal computer doesn't use this value to display/print out.

ResolutionUnit
Unit of XResolution/YResolution.

1 means no-unit
2 means inch
3 means centimeter

Software
Shows firmware(internal software of digicam) version number

DateTime
Date/Time of image was last modified.
Data format is "YYYY:MM:DD HH:MM:SS". If clock has not set or digicam doesn't have clock, the field may be filled with spaces. In usual, it has the same value of DateTimeOriginal

WhitePoint
Defines chromaticity of white point of the image.
If the image uses CIE Standard Illumination D65(known as international standard of 'daylight'), the values are '3127/10000,3290/10000'.

PrimaryChromaticities
Defines chromaticity of the primaries of the image.
If the image uses CCIR Recommendation 709 primaries, values are '640/1000,330/1000,300/1000,600/1000,150/1000,0/1000'.

YCbCrCoefficients
When image format is YCbCr, this value shows a constant to translate it to RGB format.
In usual, values are '0.299/0.587/0.114'.

YCbCrPositioning
When image format is YCbCr and uses 'Subsampling' (cropping of chroma data, all the digicam do that), defines the chroma sample point of subsampling pixel array.

1 means the center of pixel array
2 means the datum point.

ReferenceBlackWhite
Shows reference value of black point/white point.
In case of YCbCr format, first 2 show black/white of Y, next 2 are Cb, last 2 are Cr. In case of RGB format, first 2 show black/white of R, next 2 are G, last 2 are B.

Copyright
Shows copyright information

ExposureTime
Exposure time (reciprocal of shutter speed). Unit is second.

FNumber
The actual F-number(F-stop) of lens when the image was taken.

ExposureProgram
Exposure program that the camera used when image was taken.

1 means manual control
2 program normal
3 aperture priority
4 shutter priority
5 program creative (slow program)
6 program action(high-speed program)
7 portrait mode
8 landscape mode.

ISOSpeedRatings
CCD sensitivity equivalent to Ag-Hr film speedrate.

ExifVersion
Exif version number.
If the picture is based on Exif V2.1, value is "0210".

DateTimeOriginal
Date/Time of original image taken.
This value should not be modified by user program. Data format is "YYYY:MM:DD HH:MM:SS". If clock has not set or digicam doesn't have clock, the field may be filled with spaces. In the Exif standard, this tag is optional, but it is mandatory for DCF.

DateTimeDigitized
Date/Time of image digitized.
Usually, it contains the same value of DateTimeOriginal. Data format is "YYYY:MM:DD HH:MM:SS". If clock has not set or digicam doesn't have clock, the field may be filled with spaces. In the Exif standard, this tag is optional, but it is mandatory for DCF.

CompressedBitsPerPixel
The average compression ratio of JPEG (rough estimate)

ShutterSpeedValue
Shutter speed by APEX value.
To convert this value to ordinary 'Shutter Speed'; calculate this value's power of 2, then reciprocal.
For example, if the ShutterSpeedValue is '4', shutter speed is 1/(24)=1/16 second.

ApertureValue
The actual aperture value of lens when the image was taken. Unit is APEX.
To convert this value to ordinary F-number (F-stop), calculate this value's power of root 2 (=1.4142).
For example, if the ApertureValue is '5', F-number is 1.41425 = F5.6.

BrightnessValue
Brightness of taken subject, unit is APEX.
To calculate Exposure(Ev) from BrigtnessValue(Bv), you must add SensitivityValue(Sv).
Ev=Bv+Sv Sv=log2(ISOSpeedRating/3.125)
ISO100:Sv=5, ISO200:Sv=6, ISO400:Sv=7, ISO125:Sv=5.32.

ExposureBiasValue
Exposure bias(compensation) value of taking picture. Unit is APEX(EV).