HEIF (High Efficiency Image File Format) Feature Representation

Sets the quality of the compression.

Range: 0 (best quality) to 100 (worst quality)

Default: 28

The lens aperture.

The unit is the APEX value.

The color filter array (CFA) geometric pattern of the image sensor when a one-chip color area sensor is used. It does not apply to all sensing methods.

The color space information tag is always recorded as the color space specifier.

sRGB (=1) is usually used to define the color space based on the PC monitor conditions and environment. If a color space other than sRGB is used, uncalibrated (=FFFF) is set. Image data recorded as uncalibrated can be treated as sRGB when it is converted to Flashpix.

Value:

• 1 – sRGB
• FFFF – uncalibrated
• Other – reserved

Represents information specific to compressed data.

The channels of each component are arranged in order from the 1st component to the 4th. For uncompressed data the data arrangement is given in the photometric interpretation tag. However, since photometric interpretation can only express the order of Y, Cb, and Cr, this tag is provided for cases when compressed data uses components other than Y, Cb, and Cr and to enable support of other sequences.

Value:

• 0 – does not exist
• 1 – Y
• 2 – Cb
• 3 – Cr
• 4 – R
• 5 – G
• 6 – B
• Other – reserved

The default is 4 5 6 0 (if RGB uncompressed) or 1 2 3 0 (other cases).

Represents information specific to compressed data. The compression mode used for a compressed image is indicated in unit bits per pixel.

Indicates the direction of contrast processing applied by the camera when the image was shot.

Value:

• 0 – Normal
• 1 – Soft
• 2 – Hard

The use of special processing on image data, such as rendering geared to output.

When special processing is performed, the reader is expected to disable or minimize any further processing.

Value:

• 0 – normal process
• 1 – custom process
• Other – reserved

Default: 0

The date and time of image creation.

In this standard, it is the date and time the file was changed. The format is YYYY:MM:DD HH:MM:SS with time shown in 24-hour format, and the date and time separated by one blank character.

When the date and time are unknown, all the character spaces except colons (“:”) may be filled with blank characters, or else the interoperability field may be filled with blank characters. The character's string length is 20 bytes including a null character for termination.

When the field is left blank, it is treated as unknown.

The date and time when the image was stored as digital data.

If, for example, an image was captured by DSC and at the same time the file was recorded, then the heif_exif_datetimeoriginal and heif_exif_datetimedigitized will have the same contents.

The format is YYYY:MM:DD HH:MM:SS with time shown in 24-hour format, and the date and time separated by one blank character.

When the date and time are unknown, all the character spaces except colons (“:”) may be filled with blank characters, or else the interoperability field may be filled with blank characters.

The characters string length is 20 bytes including a null character for termination.

When the field is left blank, it is treated as unknown.

The date and time when the original image data was generated.

For a DSC the date and time the picture was taken are recorded. The format YYYY:MM:DD HH:MM:SS with time shown in 24-hour format, and the date and time separated by one blank character.

When the date and time are unknown, all the character spaces except colons (“:”) may be filled with blank characters.

The character string length is 20 bytes including a null character for termination.

When the field is left blank, it is treated as unknown.

The digital zoom ratio when the image was shot. If the numerator of the recorded value is 0, this indicates that digital zoom was not used.

The version of this standard supported.

Non-existence of this field is taken to mean non-conformance to the standard. Conformance to this standard is indicated by recording 0220 as 4-byte ASCII.

Since the type is UNDEFINED, there is no null character for termination.

The exposure bias.

Unit: APEX value (usually in the range of -99.99 to 99.99)

The 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.

Value:

• 0 – auto exposure
• 1 – manual exposure
• 2 – auto bracket
• Other – reserved

The class of the program used by the camera to set exposure when the picture is taken.

Value:

• 0 – Not defined
• 1 – Manual
• 2 – Normal program
• 3 – 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)
• 8 – Landscape mode (for landscape photos with the background in focus)

The exposure time of the image.

The image source.

If a DSC recorded the image, this attribute value of this tag always be set to 3, indicating that the image was recorded on a DSC.

Value:

• 3 – DSC
• Other – reserved

Default: 3

The status of flash when the images was shot.

Bit 0 indicates the flash firing status; bits 1 and 2 indicate the flash return status; bits 3 and 4 indicate the flash mode; bit 5 indicates whether the flash function is present; and bit 6 indicates “red eye” mode.

Value:

• Bit 0: 0 – flash did not fire
• Bit 0: 1 – flash fired
• Bit 1 and 2: 00 – no strobe return detection function
• Bit 1 and 2: 01 – reserved
• Bit 1 and 2: 10 – strobe return light not detected
• Bit 1 and 2: 11 – strobe return light detected
• Bit 3 and 4: 00 – unknown
• Bit 3 and 4: 01 – compulsory flash firing
• Bit 3 and 4: 10 – compulsory flash suppression
• Bit 3 and 4: 11 – auto mode
• Bit 5: 0 – flash function present
• Bit 5: 1 – no flash function
• Bit 6: 0 – no red-eye reduction mode or unknown
• Bit 6: 1 – red-eye reduction supported

The Flashpix format version supported by a FPXR file.

If the FPXR function supports Flashpix format ver. 1.0, this is indicated similarly to heif_exif_exifversion by recording 0100 as 4-byte ASCII.

Value:

• 0100 – flashpix format version 1.0
• Other – reserved

Default: 0100

The f number of the recording equipment

The actual focal length of the lens, in mm.

Conversion is not made to the focal length of a 35 mm film camera.

Indicates the equivalent focal length assuming a 35mm film camera, in mm.

A value of 0 means the focal length is unknown.

The unit for measuring heif_exif_focalplanexresolution and heif_exif_focalplaneyresolution.

This value is the same as the heif_exif_resolutionunit.

The number of pixels in the image width (x) direction per heif_exif_focalplaneresolutionunit on the camera focal plane.

The number of pixels in the image height (y) direction per heif_exif_focalplaneresolutionunit on the camera focal plane.

The degree of overall image gain adjustment.

The altitude, based on the reference.

Unit: meters

The altitude used as the reference altitude.

Value:

• 0 – above sea level
• 1 – below sea level

The name of the GPS area.

The date relative to UTC (Coordinated Universal Time).

Format: YYYY:MM:DD

The bearing to the destination point.

Value: Range from 0.00 to 359.99

The reference used for giving the bearing to the destination point.

Value:

• T – true direction
• M – magnetic direction

The distance to the destination point.

The unit used to express the distance to the destination point.

Value:

• K – kilometers per hour
• M – miles per hour
• N – knots

The latitude of the destination point.

It is expressed as three numbers giving the degrees, minutes, and seconds, respectively.

Indicates whether the latitude of the destination point is north or south.

Value:

• N – north latitude
• S – south latitude

The longitude of the destination point.

It is expressed as three numbers giving the degrees, minutes, and seconds, respectively.

Indicates whether the longitude of the destination point is east or west.

Value:

• E – east longitude
• W – west longitude

Represents whether differential correction is applied to the GPS receiver.

Value:

• 0 – measurement without differential correction
• 1 – differential correction applied

The GPS DOP (data degree of precision).

An HDOP value is written during two-dimensional measurement, and PDOP during three-dimensional measurement.

The direction of the image when it was captured.

Value: Range from 0.00 to 359.99

The reference for giving the direction of the image when it is captured.

Value:

• T – true direction
• M – magnetic direction

The latitude.

It is expressed as three numbers giving the degrees, minutes, and seconds, respectively.

Indicates whether the latitude is north or south.

Value:

• N – north latitude
• S – south latitude

The longitude.

It is expressed as three numbers giving the degrees, minutes, and seconds, respectively.

Indicates whether the longitude is east or west.

Value:

• E – east longitude
• W – west longitude

The geodetic survey data used by the GPS receiver.

The GPS measurement mode.

Value:

• 2 – two-dimensional measurement
• 3 – three-dimensional measurement

The name of the method used for location finding.

The satellites used for measurements.

This tag can be used to describe the number of satellites, their ID number, angle of elevation, azimuth, SNR and other information in ASCII notation.

The format is not specified.

The speed of GPS receiver movement.

The unit used to express the GPS receiver speed of movement.

Value:

• K – kilometers per hour
• M – miles per hour
• N – knots

The status of the GPS receiver when the image is recorded.

Value:

• A – measurement is in progress
• V – measurement is Interoperability

The time as UTC (Coordinated Universal Time).

It is expressed as three numbers giving the hour, minute, and second.

The direction of GPS receiver movement.

Value: Range from 0.00 to 359.99.

The reference for giving the direction of GPS receiver movement.

Value:

• T – true direction
• M – magnetic direction

The version of the GPS Image File Folder.

The version is given as byte sequence 2, 2, 0, 0 to indicate version 2.2.

The kind of light source.

• 0 – Unknown
• 1 – Daylight
• 2 – Fluorescent
• 3 – Tungsten (incandescent light)
• 4 – Flash
• 9 – Fine weather
• 10 – Cloudy weather
• 11 – Shade
• 12 – Daylight fluorescent (D 5700 – 7100K)
• 13 – Day white fluorescent (N 4600 – 5400K)
• 14 – Cool white fluorescent (W 3900 – 4500K)
• 15 – White fluorescent (WW 3200 – 3700K)
• 17 – Standard light A
• 18 – Standard light B
• 19 – Standard light C
• 20 – D55
• 21 – D65
• 22 – D75
• 23 – D50
• 24 – ISO studio tungsten
• 255 – Other light source

The manufacturer of the recording equipment.

This is the manufacturer of the DSC, scanner, video digitizer or other equipment that generated the image.

When the field is left blank, it is treated as unknown.

Represents a tag for manufacturers of Exif writers to record any desired information.

The contents are up to the manufacturer, but this tag should not be used for any other than its intended purpose.

The smallest F number of the lens.

Units: APEX value (usually in the range of 00.00 to 99.99, but it is not limited to this range)

The metering mode. The value can be:

• 0 – unknown (default)
• 1 – average
• 2 – center weighted average
• 3 – spot
• 4 – multispot
• 5 – pattern
• 6 – partial
• Other – reserved
• 255 – other

The model or model number of the equipment.

This is the model name of number of the DSC, scanner, video digitizer or other equipment that generated the image.

When the field is left blank, it is treated as unknown.

The image orientation viewed in terms of rows and columns.

Represents information specific to compressed data.

When a compressed file is recorded, the valid width of the meaningful image shall be recorded in this attribute, whether or not there is padding data or a restart marker.

This attribute should not exist in an uncompressed file.

Represents information specific to compressed data.

When a compressed file is recorded, the valid height of the meaningful image shall be recorded in this attribute, whether or not there is padding data or restart marker.

This attribute should not exist in an uncompressed file.

The chromaticity of the three primary colors of the image.

This tag is not usually necessary, since color space is specified in the color space information tag.

The unit of x and y resolution.

The direction of saturation processing applied by the camera when the image was shot.

Value:

• 0 – Normal
• 1 – Low saturation
• 2 – High saturation

The 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 scene type attribute.

Value:

• 0 – standard (default)
• 1 – landscape
• 2 – portrait
• 3 – night scene
• Other – reserved

The image sensor type on the camera or input device.

Value:

• 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 linear sensor
• Other – reserved

Indicates the direction of sharpness processing applied by the camera when the image was shot.

Value:

• 0 – Normal
• 1 – Soft
• 2 – Hard

The shutter speed.

Unit: APEX (Additive System of Photographic Exposure) setting

Records the name and version of the software or firmware of the camera or image input device used to generate the image.

The distance to the subject, such as Macro, Close View, or Distant View.

Used to record fractions of seconds for the DateTime tag.

Used to record fractions of seconds for the DateTimeDigitized tag.

Used to record fractions of seconds for the DateTimeOriginal tag.

Represents a tag for Exif users to write keywords or comments on the image.

The white balance mode set when the image was shot.

Value:

• 0 – auto white balance
• 1 – manual white balance
• Other – reserved

The chromaticity of the white point of the image.

This tag is not usually necessary, since color space is specified in the color space information tag.

Author tag used by Windows.

Comment tag used by Windows.

Keywords tag used by Windows.

Subject tag used by Windows.

Title tag used by Windows.

The number of pixels per heif_exif_resolutionunit in the heif_exif_imagewidth direction.

When the image resolution is unknown, 72 dpi is designated.

The matrix coefficients for transformation from RGB to YCbCr image data.

The position of chrominance components in relation to the luminance component.

This field is designated only for JPEG compressed date or uncompressed YCbCr data.

The default is 1 (centered); but when Y:Cb:Cr = 4:2:2 it is recommended in this standard that 2 (co-sited) be used to record data, in order to improve the image quality when viewed on TV systems.

When this field does not exist, the default is used.

The number of pixels per heif_exif_resolutionunit in the heif_exif_imagelength direction.

The same value as heif_exif_xresolution is designated.

Specifies whether to optimize the output file. Optimization involves calculating encoding parameters to reduce file size without decreasing image quality. However, optimization may increase translation time.

This is a writer attribute.

Enables or disables the generation of a TAB file along with the output JPEG image. Value: yes | no

Default: yes

This is a writer attribute.

Enables or disables the generation of a Esri world file along with the output JPEG image.

Default: yes

This is a writer attribute.