11
\$\begingroup\$

While my old iPad mini photos say their color space is sRGB, my new iPhone 8 photos tell me their color space is "65535" ("unknown value"). Some sources say this value means "uncalibrated", but that information is of no help. Is there a better source which tells me the true color space of the photos? I want to embed them in a PDF file and for this specify the correct color space.

$ exif IMG_8995.JPG 
EXIF tags in 'IMG_8995.JPG' ('Motorola' byte order):
--------------------+----------------------------------------------------------
Tag                 |Value
--------------------+----------------------------------------------------------
Manufacturer        |Apple
Model               |iPhone 8
Orientation         |Top-left
X-Resolution        |72
Y-Resolution        |72
Resolution Unit     |Inch
Software            |11.3.1
Date and Time       |2018:05:12 07:58:51
YCbCr Positioning   |Centered
Compression         |JPEG compression
X-Resolution        |72
Y-Resolution        |72
Resolution Unit     |Inch
Exposure Time       |1/2404 sec.
F-Number            |f/1,8
Exposure Program    |Normal program
ISO Speed Ratings   |20
Exif Version        |Exif Version 2.21
Date and Time (Origi|2018:05:12 07:58:51
Date and Time (Digit|2018:05:12 07:58:51
Components Configura|Y Cb Cr -
Shutter Speed       |11,23 EV (1/2403 sec.)
Aperture            |1,70 EV (f/1,8)
Brightness          |10,62 EV (5394,70 cd/m^2)
Exposure Bias       |0,00 EV
Metering Mode       |Spot
Flash               |Flash did not fire, compulsory flash mode
Focal Length        |4,0 mm
Subject Area        |Within rectangle (width 753, height 756) around (x,y) = (3
Maker Note          |926 bytes undefined data
Sub-second Time (Ori|700
Sub-second Time (Dig|700
FlashPixVersion     |FlashPix Version 1.0
Color Space         |Internal error (unknown value 65535)
Pixel X Dimension   |4032
Pixel Y Dimension   |3024
Sensing Method      |One-chip color area sensor
Scene Type          |Directly photographed
Exposure Mode       |Auto exposure
White Balance       |Auto white balance
Focal Length in 35mm|28
Scene Capture Type  |Standard
North or South Latit|N
Latitude            |47, 43, 40,97
East or West Longitu|E
Longitude           |13, 12, 25,38
Altitude Reference  |Sea level
Altitude            |989,768
GPS Time (Atomic Clo|05:58:51,00
Speed Unit          |K
Speed of GPS Receive|0,03549
GPS Image Direction |T
GPS Image Direction |221,05
Reference for Bearin|T
Bearing of Destinati|221,05
GPS Date            |2018:05:12
--------------------+----------------------------------------------------------
EXIF data contains a thumbnail (9560 bytes).

[UPDATE] Now, using exiftool (as suggested by mattdm):

$ exiftool IMG_8995.JPG
ExifTool Version Number         : 10.60
File Name                       : IMG_8995.JPG
Directory                       : .
File Size                       : 3.8 MB
File Modification Date/Time     : 2018:05:12 17:54:37+02:00
File Access Date/Time           : 2018:05:17 21:55:15+02:00
File Inode Change Date/Time     : 2018:05:12 17:54:37+02:00
File Permissions                : rw-r--r--
File Type                       : JPEG
File Type Extension             : jpg
MIME Type                       : image/jpeg
Exif Byte Order                 : Big-endian (Motorola, MM)
Make                            : Apple
Camera Model Name               : iPhone 8
Orientation                     : Horizontal (normal)
X Resolution                    : 72
Y Resolution                    : 72
Resolution Unit                 : inches
Software                        : 11.3.1
Modify Date                     : 2018:05:12 07:58:51
Y Cb Cr Positioning             : Centered
Exposure Time                   : 1/2404
F Number                        : 1.8
Exposure Program                : Program AE
ISO                             : 20
Exif Version                    : 0221
Date/Time Original              : 2018:05:12 07:58:51
Create Date                     : 2018:05:12 07:58:51
Components Configuration        : Y, Cb, Cr, -
Shutter Speed Value             : 1/2404
Aperture Value                  : 1.8
Brightness Value                : 10.62069397
Exposure Compensation           : 0
Metering Mode                   : Spot
Flash                           : Off, Did not fire
Focal Length                    : 4.0 mm
Subject Area                    : 3194 1215 753 756
Run Time Flags                  : Valid
Run Time Value                  : 95831447299500
Run Time Scale                  : 1000000000
Run Time Epoch                  : 0
Acceleration Vector             : -0.9967756794 0.02542742023 -0.03952735125
Sub Sec Time Original           : 700
Sub Sec Time Digitized          : 700
Flashpix Version                : 0100
Color Space                     : Uncalibrated
Exif Image Width                : 4032
Exif Image Height               : 3024
Sensing Method                  : One-chip color area
Scene Type                      : Directly photographed
Exposure Mode                   : Auto
White Balance                   : Auto
Focal Length In 35mm Format     : 28 mm
Scene Capture Type              : Standard
Lens Info                       : 3.99mm f/1.8
Lens Make                       : Apple
Lens Model                      : iPhone 8 back camera 3.99mm f/1.8
GPS Latitude Ref                : North
GPS Longitude Ref               : East
GPS Altitude Ref                : Above Sea Level
GPS Time Stamp                  : 05:58:51
GPS Speed Ref                   : km/h
GPS Speed                       : 0.03548649749
GPS Img Direction Ref           : True North
GPS Img Direction               : 221.0531915
GPS Dest Bearing Ref            : True North
GPS Dest Bearing                : 221.0531915
GPS Date Stamp                  : 2018:05:12
GPS Horizontal Positioning Error: 4 m
Compression                     : JPEG (old-style)
Thumbnail Offset                : 2114
Thumbnail Length                : 9560
Profile CMM Type                : appl
Profile Version                 : 4.0.0
Profile Class                   : Display Device Profile
Color Space Data                : RGB
Profile Connection Space        : XYZ
Profile Date Time               : 2017:07:07 13:22:32
Profile File Signature          : acsp
Primary Platform                : Apple Computer Inc.
CMM Flags                       : Not Embedded, Independent
Device Manufacturer             : APPL
Device Model                    : 
Device Attributes               : Reflective, Glossy, Positive, Color
Rendering Intent                : Perceptual
Connection Space Illuminant     : 0.9642 1 0.82491
Profile Creator                 : appl
Profile ID                      : ca1a9582257f104d389913d5d1ea1582
Profile Description             : Display P3
Profile Copyright               : Copyright Apple Inc., 2017
Media White Point               : 0.95045 1 1.08905
Red Matrix Column               : 0.51512 0.2412 -0.00105
Green Matrix Column             : 0.29198 0.69225 0.04189
Blue Matrix Column              : 0.1571 0.06657 0.78407
Red Tone Reproduction Curve     : (Binary data 32 bytes, use -b option to extract)
Chromatic Adaptation            : 1.04788 0.02292 -0.0502 0.02959 0.99048 -0.01706 -0.00923 0.01508 0.75168
Blue Tone Reproduction Curve    : (Binary data 32 bytes, use -b option to extract)
Green Tone Reproduction Curve   : (Binary data 32 bytes, use -b option to extract)
Image Width                     : 4032
Image Height                    : 3024
Encoding Process                : Baseline DCT, Huffman coding
Bits Per Sample                 : 8
Color Components                : 3
Y Cb Cr Sub Sampling            : YCbCr4:2:0 (2 2)
Aperture                        : 1.8
GPS Altitude                    : 989.7 m Above Sea Level
GPS Date/Time                   : 2018:05:12 05:58:51Z
GPS Latitude                    : 47 deg 43' 40.97" N
GPS Longitude                   : 13 deg 12' 25.38" E
GPS Position                    : 47 deg 43' 40.97" N, 13 deg 12' 25.38" E
Image Size                      : 4032x3024
Megapixels                      : 12.2
Run Time Since Power Up         : 1 days 2:37:11
Scale Factor To 35 mm Equivalent: 7.0
Shutter Speed                   : 1/2404
Create Date                     : 2018:05:12 07:58:51.700
Date/Time Original              : 2018:05:12 07:58:51.700
Thumbnail Image                 : (Binary data 9560 bytes, use -b option to extract)
Circle Of Confusion             : 0.004 mm
Field Of View                   : 65.5 deg
Focal Length                    : 4.0 mm (35 mm equivalent: 28.0 mm)
Hyperfocal Distance             : 2.07 m
Light Value                     : 15.2
Improve this question
\$\endgroup\$

2 Answers 2

Reset to default
14
\$\begingroup\$

For whatever reason, the ColorSpace tag is not very useful in EXIF. The only standard values are 1 (sRGB) and 65535 ("uncalibrated"). All other values are reserved. Some cameras use them to mean Adobe RGB or something else, but this is non-standard. Apple is, in fact, using Something Else, and that's found elsewhere in the metadata. With ExifTool, looking for tags starting with Profile, I found:

Profile CMM Type                : Apple Computer Inc.
Profile Version                 : 4.0.0
Profile Class                   : Display Device Profile
Profile Connection Space        : XYZ
Profile Date Time               : 2017:07:07 13:22:32
Profile File Signature          : acsp
Profile Creator                 : Apple Computer Inc.
Profile ID                      : ca1a9582257f104d389913d5d1ea1582
Profile Description             : Display P3
Profile Copyright               : Copyright Apple Inc., 2017

which leads us to Apple Core Graphics documentation which says:

displayP3

The name of the Display P3 color space, created by Apple Inc. This color space uses the DCI P3 primaries, a D65 white point, and the same gamma curve as the sRGB color space.

You can read more about the DCI-P3 colorspace on Wikipedia.

Improve this answer
\$\endgroup\$
4
  • \$\begingroup\$ Thank you. Then I was using the wrong tool. I added the result with the command exiftool to my question. \$\endgroup\$
    – ideaboxer
    May 17, 2018 at 21:15
  • \$\begingroup\$ @ideaboxer Yep, looks like your file has the same info as the sample one I found. \$\endgroup\$
    – mattdm
    May 17, 2018 at 21:19
  • \$\begingroup\$ What command is used in exiftool to find tags like these? \$\endgroup\$
    – P A N
    Aug 23, 2022 at 19:45
  • \$\begingroup\$ @PAN No particular tool — it's not an unreasonable amount of output. \$\endgroup\$
    – mattdm
    Aug 24, 2022 at 12:59
0
\$\begingroup\$

all current production Apple displays and software using DCI-P3 (DCI/P3) color space. wiki reference

Improve this answer
\$\endgroup\$
3
  • \$\begingroup\$ Apparently it isn't exactly DCI-P3. \$\endgroup\$
    – Mark Ransom
    Jun 14, 2018 at 17:12
  • \$\begingroup\$ @MarkRansom The only difference is the gamma curves. Display P3 uses sRGB's curve, rather than DCI-P3's 2.6. Apparently, it leads to a reasonable image if a non-color aware program assumes the Display P3 image is sRGB. \$\endgroup\$
    – user71659
    Jun 14, 2018 at 18:02
  • 3
    \$\begingroup\$ All of this is covered in my previous answer. Including the same wikipedia link. Just sayin'. :) \$\endgroup\$
    – mattdm
    Jun 14, 2018 at 19:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.