Value

Meaning

CMNT_LAST

Last defined number for comments. To get all comments, you can use the comment type constant as a loop counter. The first constant is 0 and the last is CMNT_LAST.

Value

Meaning

CMNT_SZARTIST

Person who created the image.

CMNT_SZCOPYRIGHT

Copyright notice.

CMNT_SZDATETIME

Date and time (YYYY:MM:DD HH:MM:SS). The field length is 20, counting the NULL terminator.

CMNT_SZDESC

Description of the image.

CMNT_SZHOSTCOMP

Computer and operating system in use.

CMNT_SZMAKE

Manufacturer of the equipment used to create the image.

CMNT_SZMODEL

Model name and number of the equipment.

CMNT_SZNAMEOFDOC

Name of the document from which the image was scanned.

CMNT_SZNAMEOFPAGE

Page name from which the image was scanned.

CMNT_SZSOFTWARE

Name and version of software package used to create the image.

Value

Meaning

CMNT_EXIFVERSION

Exif version. LEADTOOLS always writes this value as 0100, meaning version 1. Data type: UNDEFINED. Length: 4.

CMNT_SZSUBSECTIME

Decimal extension for seconds that are specified in the CMNT_SZDATETIME field. Data type: ASCII. Length: variable.

CMNT_SZDATETIMEORIGINAL

Date and time the original image is captured. The format is YYYY:MM:DD HH:MM:SS. The time is in a 24-hour format, and a blank space is left between the date and the time. Data type: ASCII. Length: 20.

CMNT_SZSUBSECTIMEORIGINAL

Decimal extension for seconds that are specified in the CMNT_SZDATETIMEORIGINAL field. Data type: ASCII. Length: variable.

CMNT_SZDATETIMEDIGITIZED

Date and time the file is generated. If the file is generated directly, as with a digital camera, this is the same as the time the original image is captured. Data type: ASCII. Length: 20.

CMNT_SZSUBSECTIMEDIGITIZED

Decimal extension for seconds that are specified in the CMNT_SZDATETIMEDIGITIZED field. Data type: ASCII. Length: variable.

CMNT_SHUTTERSPEEDVALUE

Shutter speed. The unit of measure is APEX. Data type: SRATIONAL. Length: 1.

CMNT_APERTURE

Aperture value. This is the ratio of lens aperture for the focal length. The unit of measure is APEX. Data type: RATIONAL. Length: 1.

CMNT_BRIGHTNESS

Brightness value. Data type: SRATIONAL. Length: 1.

CMNT_EXPOSUREBIAS

Exposure bias. This is the value for correcting a biased exposure. The unit of measure is APEX. Data type: SRATIONAL. Length: 1.

CMNT_MAXAPERTURE

Minimum lens f-number. Data type: RATIONAL. Length: 1.

CMNT_SUBJECTDISTANCE

Distance from lens to subject (in meters). Data type: RATIONAL. Length: 1.

CMNT_METERINGMODE

Photometry mode. Possible values are

0 = Unidentified

1 = Average

2 = Center Weighted Average

3 = Spot

4 = MultiSpot

5 = Pattern

6 = Partial

255 = Others

Data type: SHORT. Length: 1.

CMNT_LIGHTSOURCE

Light source. Possible values are

0 = Unidentified

1 = Daylight

2 = Florescence light

3 = Tungsten Lamp

17 = Standard light source A

18 = Standard light source B

19 = Standard light source C

20 = D55

21 = D65

22 = D75

255 = Others

Data type: SHORT. Length: 1.

CMNT_FLASH

Flash On/Off. Possible values are 1 for on or 0 for off. Data type: SHORT. Length: 1.

CMNT_FOCALLENGTH

Focal length, measured in millimeters. Data type: RATIONAL. Length: 1.

CMNT_EXPOSURETIME

Exposure time, expressed as a fraction of a second. Data type: RATIONAL. Length: 1.

CMNT_FNUMBER

The actual lens F stop (ratio of lens aperture to focal length). Data type: RATIONAL. Length: 1.

CMNT_MAKERNOTE

Maker note. Data type: UNDEFINED. The creator of the file determines the data format.

CMNT_USERCOMMENT

User comment. Data type: UNDEFINED. Length: variable. The first eight bytes specify the data format, and the remainder of the comment is in the specified format. The first eight bytes can be any of the following:

41 53 43 49 49 00 00 00 = ASCII

4A 49 53 00 00 00 00 00 = JIS (Japanese)

00 00 00 00 00 00 00 00 = Undefined

CMNT_SUPPORTEDFLASHPIXVERSION

Supported FlashPix version (Exif 2.0). LEADTOOLS always writes 0100 here. Data type: UNDEFINED. Length: 4

CMNT_COLORSPACE

Color space (Exif 2.0). Specifies whether the color is calibrated or not. LEADTOOLS always writes this value as 1. Data type: SHORT. Length: 1 Possible values are:

1 = sRGB (PC monitor conditions)

0xFFFF = Uncalibrated

Other = reserved

CMNT_EXPOSUREPROGRAM

Exposure program (Exif 2.0) The class of the program used by the camera to set exposure when the picture is taken. Data type: SHORT. Length = 1. Possible values are:

0 = Not defined

1 = Manual

2 = Aperture priority

4 = Shutter priority

5 = Creative program (biased toward depth of field)

6 = Action program (biased toward fast shutter speed)

7 = Portrait mode (for closeup photos with the background out of focus)

Other = reserved

CMNT_SZSPECTRALSENSITIVITY

Spectral sensitivity (Exif) - The spectral sensitivity of each channel of the camera used. It is an ASCII string compatible with the standard developed by the ASTM technical committee. Data type: ASCII. Length: any

CMNT_ISOSPEEDRATINGS

ISO speed ratings (Exif) - the ISO speed and the ISO Latitude of the camera or input device as specified in ISO 12232 Data type: SHORT. Length: any

CMNT_OPTOELECTRICCOEFFICIENT

Optoelectric coefficient (Exif) - Opto-Electric Conversion function specified in ISO 14524. OECF is the relationship between the camera optical input and the image values. Data type: UNDEFINED. Length: ANY. This is an array of m rows and n columns. For information on how it is recorded, refer to OECF.

CMNT_SZRELATEDSOUNDFILE

Related audio file (Exif) - the name of an audio file related to the image data. The name should be 8 ASCII chars + '.' + 3 chars for extension + NULL. Data type: ASCII. Length: 13.

CMNT_FLASHENERGY

Flash energy (Exif) - the strobe energy at the time the image iscaptured, as measured in Beam Candle Power Seconds (BPCS) Data type: RATIONAL. Length: 1

CMNT_SPATIALFREQUENCYRESPONSE

Spatial frequency response (Exif) - the camera or input device spatial frequency table and SFR values in the direction of image width, image height and diagonal direction, as specified in ISO 12233. Data type: UNDEFINED. Length: ANY This is an array of m rows and n columns.For information on how this is recorded, refer to SFR.

CMNT_FOCALPLANEXRESOLUTION

Focal plane X Resolution (Exif) - the number of dots per resolution unit on the camera focal plane in the image width (X) direction. The resolution unit is given by CMNT_FOCALPLANERESOLUTIONUNIT. If CMNT_FOCALPLANERESOLUTIONUNIT is not set, the unit will be considered to be 2 ("dots per inch"). Data type: RATIONAL. Length: 1

CMNT_FOCALPLANEYRESOLUTION

Focal plane Y Resolution (Exif) - the number of dots per resolution unit on the camera focal plane in the image height (Y) direction. The resolution unit is given by CMNT_FOCALPLANERESOLUTIONUNIT. If CMNT_FOCALPLANERESOLUTIONUNIT is not set, the unit will be considered to be 2 (“dots per inch”). Data type: RATIONAL. Length: 1

CMNT_SUBJECTLOCATION

Subject location (Exif) - the location of the main subject in the scene. The first value is the X column number and the second is the Y row number. Data type: SHORT. Length: 2

CMNT_EXPOSUREINDEX

Exposure index (Exif) - the image sensor type on the camera or input device. Data type: SHORT. Length: 1

CMNT_SENSINGMETHOD

Sensing method (Exif) - the image sensor type on the camera or input device. Data type: SHORT. Length: 1 Possible values are:

1 = not defined

2 = one-chip color area sensor

3 = two-chip color area sensor

4 = three-chip color area sensor

5 = color sequential area sensor

7 = trilinear sensor

8 = color sequential sensor

other = reserved

CMNT_FILESOURCE

File source (Exif) - the image source. If a digital camera recorded the image, the value will always be 3, to indicate that the image was recorded on a digital camera. Data type: SHORT. Length: 1 Possible values are:

3 = image recorded on a DSC (Digital Still Camera)

other = reserved

CMNT_SCENETYPE

Scene type (Exif) - the type of scene. If a DSC recorded the image, this value will always be 1, indicating that the image was directly photographed. Data type: UNDEFINED. Length: 1 Possible values are:

1 = a directly photographed image

other = reserved

CMNT_CFAPATTERN

CFA Pattern (Exif) - the color filter array (CFA) geometric pattern of the image sensor when a one-chip color sensor was applied. It does not apply to any other sensing methods. Data type: UNDEFINED. Length: ANY This is an array m x n (horz x vertical), where the pattern is repeated every m pixels on the horizontal and n pixels on the vertical. For a table of the layout, refer to CFA.

CMNT_SUBJECTAREA

Location and area of the main subject in the overall scene. Data type: SHORT. Count: 2 (Location of the subject is given in X, Y coordinates), 3 (Area of the main subject is given as a circle, X, Y, D, where X and Y are the center coordinates and D is the diameter.) and 4 (Area of the main subject is given as a rectangle, X, Y, W, H, where X and Y are the center coordinates, W is the width or the rectangle and H is the height of the rectangle.).

CMNT_CUSTOMRENDERED

Use of special processing on image data, such as rendering geared toward output. When special processing is performed, the reader is expected to disable or minimize any further processing. Data type: SHORT; Count: 1; Possible Values: 0 (Normal process), 1 (Custom process), Other (Reserved). Default: 0;

CMNT_EXPOSUREMODE

Exposure mode set when the image was shot. In auto-bracketing mode the camera shoots a series of frames of the same scene at different exposure settings. Tag: 41986; Data type: SHORT; Count: 1; Possible values are: 0 (Auto exposure), 1 (Manual exposure), 2 (Auto-bracket), Other (Reserved); Default: none.

CMNT_WHITEBALANCE

White balance mode set when the image was shot. Data type: SHORT; Count: 1; Possible values are: 0 (Auto white balance), 1 (Manual white balance), Other (Reserved); Default: none.

CMNT_DIGITALZOOMRATIO

Digital zoom ratio set when the image was shot. If the numerator of the recorded value is 0, the digital zoom was not used. Data type: RATIONAL; Count: 1; Default: none.

CMNT_FOCALLENGTHIN35MMFILM

Equivalent focal length, assuming a 35mm film camera, in mm. A value of 0 means the focal length is unknown. Note that this comment is different from the CMNT_FOCALLENGTH comment. Data type: SHORT; Count: 1; Default: none.

CMNT_SCENECAPTURETYPE

Type of scene that was shot. It can also be used to record the mode in which the image was shot. Note that this differs from the CMNT_SCENETYPE comment. Data type: SHORT; Count: 1; Possible values are: 0 (Standard), 1 (Landscape), 2 (Portrait), 3 (Night scene), Other (Reserved); Default: 0.

CMNT_GAINCONTROL

Degree of overall image gain adjustment. Data type: SHORT; Count: 1; Possible values are: 0 (None), 1 (Low gain up), 2 (High gain up), 3 (Low gain down), 4 (High gain down), Other (Reserved); Default: none.

CMNT_CONTRAST

Direction of contrast processing applied by the camera when the image was shot. Data type: SHORT; Count: 1; Possible values are: 0 (Normal), 1 (Soft), 2 (Hard), Other (Reserved); Default: 0.

CMNT_SATURATION

Direction of saturation processing applied by the camera when the image was shot. Data type: SHORT; Count: 1; Possible values are: 0 (Normal), 1 (Low saturation), 2 (High saturation), Other (Reserved); Default: 0.

CMNT_SHARPNESS

Direction of sharpness processing applied by the camera when the image was shot. Data type: SHORT; Count: 1; Possible values are: 0 (Normal), 1 (Soft), 2 (Hard), Other (Reserved); Default: 0.

CMNT_DEVICESETTINGSDESCRIPTION

Information on the picture-taking conditions of a particular camera model. Used only to indicate the picture-taking conditions in the reader. Data type: UNDEFINED; Count: Any; The data is recorded in Unicode using SHORT fro the number of display rows and columns and UNDEFINED for the camera settings. The Unicode (UCS –2) string including Signature is NULL terminated. The specifics of the Unicode string are as given in ISO/IEC 10464-1. Default: none.

CMNT_SUBJECTDISTANCERANGE

Distance to the subject. Data type: SHORT; Count: 1; Possible values are: 0 (Unknown), 1 (Macro), 2 (Close view), 3 (Distant view), Other (Reserved); Default: none.

CMNT_SZIMAGEUNIQUEID

Identifier assigned uniquely to each image. It is recorded as an ASCII string equivalent to hexadecimal notation and 128-bit fixed length. Tag: 42016; Data type: ASCII; Count: 33; Default: none

Value

Meaning

CMNT_GPSVERSIONID

Version number of the GPS image file directory (IFD). The current version is 2.0.0.0. This comment must be included when any GPS comments are used. Unlike the CMNT_EXIFVERSION comment, this comment is written in bytes. A version written as 2.0.0.0 is actually 0x02000000 when coded. Data type: BYTE. Length: 4.

CMNT_GPSLATITUDEREF

North or south latitude. Possible values are "N" for north and "S" for south. Data type: ASCII. Length: 2.

CMNT_GPSLATITUDE

Latitude, expressed as three RATIONAL values. When expressed in degrees, minutes, and seconds, latitude is written as dd/1,mm/1,ss/1. If degrees and minutes are used as the units, and minutes are written with fractions to two decimal places, then latitude is expressed as dd/1,mmmm/100,0/1. Data type: RATIONAL. Length: 3.

CMNT_GPSLONGITUDEREF

East or west longitude. Possible values are "E" for east and "W" for west. Data type: ASCII. Length: 2.

CMNT_GPSLONGITUDE

The longitude, expressed as three RATIONAL values. When expressed in degrees, minutes and seconds, longitude is written as ddd/1,mm/1,ss/1. If degrees and minutes are used as the units, and minutes are written with fractions to two decimal places, then longitude is expressed as dd/1,mmmm/100,0/1. Data type: RATIONAL. Length: 3.

CMNT_GPSALTITUDEREF

Reference altitude. In the current version, sea level is used as the reference, which must be zero. The reference unit is meters. Data type: BYTE. Length: 1.

CMNT_GPSALTITUDE

Altitude, in meters, relative to the reference altitude. Data type: RATIONAL. Length: 1.

CMNT_GPSTIMESTAMP

Time stamp in UTC (Coordinated Universal Time) time. The time is expressed as three RATIONAL values, for hours, minutes, and seconds. Data type: RATIONAL. Length: 3.

CMNT_GPSSATELLITES

GPS satellites used for measurement. The coding format is not stipulated. This comment can be used to code information such as the number of satellites, the satellite number, the satellite's angle of elevation, its azimuth, and its SNR. If the GPS receiver cannot make a measurement, this comment is NULL. Data type: ASCII. Length: variable.

CMNT_GPSSTATUS

Status of the GPS receiver at when the image is recorded. Possible values are "A" when measurement in progress and "V" when measurement is interrupted. Data type: ASCII. Length: 2.

CMNT_GPSMEASUREMODE

GPS measurement mode. A value of "2" denotes two-dimensional measurement, and "3" denotes three-dimensional measurement. Data type: ASCII. Length: 2.

CMNT_GPSDOP

DOP (data precision) value. This comment is an HDOP value during two-dimensional measurement and a PDOP value during three-dimensional measurement. Data type: RATIONAL. Length: 1.

CMNT_GPSSPEEDREF

Unit for measuring speed. Possible values are "K" for kilometers, "M" for miles, and "N" for knots. Data type: ASCII. Length: 2.

CMNT_GPSSPEED

Speed of the GPS receiver. Data type: RATIONAL. Length: 1.

CMNT_GPSTRACKREF

Reference for direction of movement. Possible values are "T" for a true direction and "M" for a magnetic. Data type: ASCII. Length: 2

CMNT_GPSTRACK

Direction of GPS receiver movement. The range of values is 0.00 to 359.00. Data type: RATIONAL. Length: 1.

CMNT_GPSIMGDIRECTIONREF

Reference for the direction of photography in the recorded image. Possible values are "T" for a true direction and "M" for a magnetic. Data type: ASCII. Length: 2.

CMNT_GPSIMGDIRECTION

Direction of photography in the recorded image. The range of values is 0.00 to 359.00. Data type: RATIONAL. Length: 1.

CMNT_GPSMAPDATUM

Geodetic survey data used by the receiver. If the geodetic survey data is restricted to Japan, this tag value is "TOKYO" or "WGS-84". Data type: ASCII. Length: variable.

CMNT_GPSDESTLATITUDEREF

North or south latitude for the destination point. Possible values are "N" for north and "S" for south. Data type: ASCII. Length: 2.

CMNT_GPSDESTLATITUDE

Latitude of the destination point. The latitude is expressed as three RATIONAL values, indicating degrees, minutes and seconds. Data type: RATIONAL. Length: 3.

CMNT_GPSDESTLONGITUDERE

East or west longitude for the destination point. Possible values are "E" for east and "W" for west. Data type: ASCII. Length: 2.

CMNT_GPSDESTLONGITUDE

Longitude of the destination point. The longitude is expressed as three RATIONAL values, indicating degrees, minutes and seconds. Data type: RATIONAL. Length: 3.

CMNT_GPSDESTBEARINGREF

Reference for the bearing to the destination point. Possible values are "T" for a true direction and "M" for a magnetic. Data type: ASCII. Length: 2.

CMNT_GPSDESTBEARING

Bearing to the destination point. The range of values is 0.00 to 359.00. Data type: RATIONAL. Length: 1.

CMNT_GPSDESTDISTANCEREF

Unit for measuring distance to the destination point. Possible values are "K" for kilometers, "M" for miles, and "N" for nautical miles. Data type: ASCII. Length: 2.

CMNT_GPSDESTDISTANCE

Distance to the destination point. Data type: RATIONAL. Length: 1.

CMNT_GPSPROCESSINGMETHOD

Processing method. Data type: Byte. Length: Any.

CMNT_GPSAREAINFORMATION

Area. Data type: Byte. Length: Any.

CMNT_GPSDATESTAMP

Date. Data type: SZ. Length: 11.

CMNT_GPSDIFFERENTIAL

Differential. Data type: Short. Length: 1.