Any differences between identify --verbose and exiftool?

by shirish   Last Updated March 27, 2015 15:29 PM

Wanted to know if people know of any major differences between identify --verbose and exiftool. A picture here :-

─[$] identify -verbose me_at_minidebconf_thumbnail.jpeg                                                                              [4:23:33]
Image: me_at_minidebconf_thumbnail.jpeg
  Format: JPEG (Joint Photographic Experts Group JFIF format)
  Mime type: image/jpeg
  Class: DirectClass
  Geometry: 96x96+0+0
  Units: Undefined
  Type: TrueColor
  Endianess: Undefined
  Colorspace: sRGB
  Depth: 8-bit
  Channel depth:
    red: 8-bit
    green: 8-bit
    blue: 8-bit
  Channel statistics:
    Pixels: 9216
      min: 0 (0)
      max: 255 (1)
      mean: 133.799 (0.524702)
      standard deviation: 53.1449 (0.208412)
      kurtosis: -0.294846
      skewness: -0.0251616
      min: 0 (0)
      max: 255 (1)
      mean: 102.061 (0.400239)
      standard deviation: 56.3748 (0.221078)
      kurtosis: 0.0271158
      skewness: 0.613543
      min: 0 (0)
      max: 234 (0.917647)
      mean: 49.6539 (0.194721)
      standard deviation: 55.8819 (0.219145)
      kurtosis: 0.704774
      skewness: 1.33143
  Image statistics:
      min: 0 (0)
      max: 255 (1)
      mean: 95.1713 (0.373221)
      standard deviation: 55.1522 (0.216283)
      kurtosis: 1.32169
      skewness: 0.533932
  Rendering intent: Perceptual
  Gamma: 0.454545
    red primary: (0.64,0.33)
    green primary: (0.3,0.6)
    blue primary: (0.15,0.06)
    white point: (0.3127,0.329)
  Background color: white
  Border color: srgb(223,223,223)
  Matte color: grey74
  Transparent color: black
  Interlace: None
  Intensity: Undefined
  Compose: Over
  Page geometry: 96x96+0+0
  Dispose: Undefined
  Iterations: 0
  Compression: JPEG
  Quality: 80
  Orientation: Undefined
    date:create: 2015-03-26T04:21:09+06:00
    date:modify: 2015-03-26T04:20:23+06:00
    icc:copyright: FB
    icc:description: c2
    icc:manufacturer: c2
    icc:model: c2
    jpeg:colorspace: 2
    jpeg:sampling-factor: 2x2,1x1,1x1
    signature: dc33cda4167cd6ec1adee6a8856798c2659aac0c81228b65627cf254fa1ad6a8
    Profile-icc: 524 bytes
    filename: me_at_minidebconf_thumbnail.jpeg
    verbose: true
  Tainted: False
  Filesize: 3.46KB
  Number pixels: 9.22K
  Pixels per second: 9.216EB
  User time: 0.000u
  Elapsed time: 0:01.000
  Version: ImageMagick 6.8.9-9 Q16 x86_64 2015-01-05

and here's exiftool :-

[$] exiftool me_at_minidebconf.jpg                                                                                                  [4:24:15]
ExifTool Version Number         : 9.74
File Name                       : me_at_minidebconf.jpg
Directory                       : .
File Size                       : 66 kB
File Modification Date/Time     : 2015:01:29 20:59:16+05:30
File Access Date/Time           : 2015:03:26 04:04:26+05:30
File Inode Change Date/Time     : 2015:03:01 21:40:44+05:30
File Permissions                : rw-r--r--
File Type                       : JPEG
MIME Type                       : image/jpeg
JFIF Version                    : 1.02
Resolution Unit                 : None
X Resolution                    : 1
Y Resolution                    : 1
Current IPTC Digest             : 63345b91c4c72d05bf1b1d36ddf7038d
Original Transmission Reference : NDRpuPLS7BKWF_g7lXPe
Special Instructions            : FBMD01000ac20300009d21000076470000724d000026550000116e00006f9c000006a3000064ab0000fab40000fb080100
Profile CMM Type                : lcms
Profile Version                 : 2.1.0
Profile Class                   : Display Device Profile
Color Space Data                : RGB
Profile Connection Space        : XYZ
Profile Date Time               : 2012:01:25 03:41:57
Profile File Signature          : acsp
Primary Platform                : Apple Computer Inc.
CMM Flags                       : Not Embedded, Independent
Device Manufacturer             : 
Device Model                    : 
Device Attributes               : Reflective, Glossy, Positive, Color
Rendering Intent                : Perceptual
Connection Space Illuminant     : 0.9642 1 0.82491
Profile Creator                 : lcms
Profile ID                      : 0
Profile Description             : c2
Profile Copyright               : FB
Media White Point               : 0.9642 1 0.82491
Media Black Point               : 0.01205 0.0125 0.01031
Red Matrix Column               : 0.43607 0.22249 0.01392
Green Matrix Column             : 0.38515 0.71687 0.09708
Blue Matrix Column              : 0.14307 0.06061 0.7141
Red Tone Reproduction Curve     : (Binary data 64 bytes, use -b option to extract)
Green Tone Reproduction Curve   : (Binary data 64 bytes, use -b option to extract)
Blue Tone Reproduction Curve    : (Binary data 64 bytes, use -b option to extract)
Image Width                     : 899
Image Height                    : 600
Encoding Process                : Progressive DCT, Huffman coding
Bits Per Sample                 : 8
Color Components                : 3
Y Cb Cr Sub Sampling            : YCbCr4:2:0 (2 2)
Image Size                      : 899x600

at first glance identify --verbose seems to be telling more about the image than exiftool, are there any interesting things that people can point out ?

Answers 1

One difference I believe is that Identify reads the whole image file into memory and then extracts the EXIF data. I don't think exiftool has to do that because it is only getting the EXIF/IPTC metadata.

I'm not sure how much metadata Identify understands. Exiftool is specifically designed to handle not only EXIF metadata but also IPTC and XMP amongst others and can set that data very easily too. It also has specific code to handle many manufacturers maker codes. It is very well tested and under continuous development.

I don't think Identify has the high level functions to set/get such a wide range of metadata. Geotags are another area that Exiftool handles that I'm not sure Identify does.

On the other hand, identify appears to be saying more about the image content (stats)?

UPDATE: You can see the purposes of IPTC and XMP easily enough using Wikipedia.

IPTC is a set of additional standard metadata originally used by newspapers. I use it extensively to catalogue my own images with author, copyright, geocoding, etc.

XMP is Adobe's extended metadata format, using embedded XML, for their products. It isn't as well supported outside Adobe products. Many free and lowcost tools as well as professional ones support IPTC. It is even possible to use BOTH together!!

UPDATE: In my view, IPTC is the best metadata format to use for information beyond the camera data. It is very widely supported both in free and commercial tools and recognised - even required - if you ever want to sell any photos.

Some useful Windows tools that handle EXIF and IPTC:

  • Geosetter - This hasn't changed since 2011 but still works fine. It uses ExifTool which does get regularly updated & it detects updated versions of that. You can set any IPTC field with this though position and direction are its focus.
  • IPTCExt - Although last updated in 2005, this excellent Windows Shell Extension gives you access to EXIF and IPTC metadata by right-clicking on an image in Windows Explorer
  • Google Picassa - image catalogue software, free from Google. Understands some IPTC data and can set it too though you need to treat that with caution as there is some confusion about whether subsequent updates are saved in its database rather than the file unless you export the file again. I recommend doing some experiments for yourself.

UPDATE 2: I don't often use Linux desktop but here are some posibilities:

As always, WikiPedia has a useful list of metadata editors too though it is mainly Windows software.

Julian Knight
Julian Knight
March 25, 2015 23:29 PM

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