missing functionality when using imfinfo instead of exifread

I use the function exifread in a script and get the warning:

EXIFREAD will be removed in a future release.  Please use IMFINFO instead.

However, the information I want from the exif tag is the Orientation of the camera, which appears as a field with exifread but doesn't seem to be gathered by imfinfo. In fact, imfinfo has significantly fewer (and different) fields (see below). Could anyone shed some light on this? Why is some functionality being removed with the soon to be deprecated exifread? Is there a function to get an exhaustive exif read out?

Thanks for your help!

imfinfo =
           Filename: '~'
        FileModDate: '07-Aug-2014 09:55:22'
           FileSize: 911121
             Format: 'jpg'
      FormatVersion: ''
              Width: 4272
             Height: 2848
           BitDepth: 24
          ColorType: 'truecolor'
    FormatSignature: ''
    NumberOfSamples: 3
       CodingMethod: 'Huffman'
      CodingProcess: 'Sequential'
            Comment: {}

vs.

exiftag = 
            SceneCaptureType: 0
                WhiteBalance: 0
                ExposureMode: 1
              CustomRendered: 0
    FocalPlaneResolutionUnit: 2
       FocalPlaneYResolution: 4.7866e+03
       FocalPlaneXResolution: 4.7204e+03
             PixelYDimension: 4272
             PixelXDimension: 2848
                  ColorSpace: 1
             FlashpixVersion: '0100'
         SubSecTimeDigitized: '05'
          SubSecTimeOriginal: '05'
                  SubSecTime: '05'
                 UserComment: [1x255 char]
                 FocalLength: 50
                       Flash: 16
                MeteringMode: 5
           ExposureBiasValue: 0
               ApertureValue: 5.6250
           ShutterSpeedValue: 5.6250
     ComponentsConfiguration: [1 2 3 0]
           DateTimeDigitized: '2014:05:14 15:55:54'
            DateTimeOriginal: '2014:05:14 15:55:54'
                 ExifVersion: '0230'
             ISOSpeedRatings: 100
             ExposureProgram: 1
                     FNumber: 7.1000
                ExposureTime: 0.0200
                   Copyright: ''
            YCbCrPositioning: 2
                      Artist: ''
                    DateTime: '2014:06:04 17:20:19'
                    Software: 'Microsoft Windows Photo Viewer 6.2.9200.16384'
              ResolutionUnit: 2
                 YResolution: 72
                 XResolution: 72
                 Orientation: 1
                       Model: 'Canon EOS 1100D'
                        Make: 'Canon'
                   Thumbnail: [1x1 struct]

Answer 1

[Friedrich]

Hi,

what MATLAB version are you using? Normally the returned structure of iminfo should have a field called DigitalCamera which contains the EXIF information.

In R2014a I get something like this:

>> info = imfinfo('img_1771.jpg')

info = 

            Filename: 'C:\Users\fhempel\Desktop\tmp\img_1771.jpg'
         FileModDate: '07-Aug-2014 12:09:45'
            FileSize: 32764
              Format: 'jpg'
       FormatVersion: ''
               Width: 480
              Height: 360
            BitDepth: 24
           ColorType: 'truecolor'
     FormatSignature: ''
     NumberOfSamples: 3
        CodingMethod: 'Huffman'
       CodingProcess: 'Sequential'
             Comment: {}
                Make: 'Canon'
               Model: 'Canon PowerShot S40'
         Orientation: 1
         XResolution: 180
         YResolution: 180
      ResolutionUnit: 'Inch'
            DateTime: '2003:12:14 12:01:44'
    YCbCrPositioning: 'Centered'
       DigitalCamera: [1x1 struct]
       ExifThumbnail: [1x1 struct]

>> info.DigitalCamera

ans = 

                ExposureTime: 0.0020
                     FNumber: 4.9000
                 ExifVersion: [48 50 50 48]
            DateTimeOriginal: '2003:12:14 12:01:44'
           DateTimeDigitized: '2003:12:14 12:01:44'
     ComponentsConfiguration: 'YCbCr'
      CompressedBitsPerPixel: 5
           ShutterSpeedValue: 8.9688
               ApertureValue: 4.6563
           ExposureBiasValue: 0
            MaxApertureValue: 2.9709
                MeteringMode: 'CenterWeightedAverage'
                       Flash: 'Flash did not fire, no strobe return detection function, auto flash mode, f...'
                 FocalLength: 21.3125
                   MakerNote: [1x450 double]
                 UserComment: [1x264 double]
             FlashpixVersion: [48 49 48 48]
                  ColorSpace: 'sRGB'
            CPixelXDimension: 2272
            CPixelYDimension: 1704
         InteroperabilityIFD: [1x1 struct]
       FocalPlaneXResolution: 8.1143e+03
       FocalPlaneYResolution: 8.1143e+03
    FocalPlaneResolutionUnit: 2
               SensingMethod: 'One-chip color area sensor'
                  FileSource: 'DSC'
              CustomRendered: 'Normal process'
                ExposureMode: 'Auto exposure'
                WhiteBalance: 'Auto white balance'
            DigitalZoomRatio: 1
            SceneCaptureType: 'Standard'

[Sian]

Hi Friedrich, thanks! Unfortunately I can't share the file. But your answer made me realise that the file I was trying to extract exif info from was a copy of the original (copied in Windows explorer). When I imfinfo the original, I can see all the data in the DigitalCamera field. I didn't realise that you lose a lot of exif info when copying images in Windows explorer. I guess the next question is how to copy images without losing the exif information... :)

[Friedrich]

When I copy my small example file around all the information stay. So I don't loose the EXIF info on my machine.

[Sian]

Hmm that's odd, I tried the copying operation again and wasn't able to recreate the error... there must be another problem in the pipeline, I will figure it out. Thanks very much for your help!