Use exiftool JSON output

[laino]

Exiftool can output in JSON, probably should use that:

$ exiftool -j Images/test.jpg 
[{
  "SourceFile": "Images/test.jpg",
  "ExifToolVersion": 10.55,
  "FileName": "193762.jpg",
  "Directory": "Images",
  "FileSize": "2.9 MB",
  "FileModifyDate": "2017:09:28 19:34:19+02:00",
  "FileAccessDate": "2017:09:28 19:34:19+02:00",
  "FileInodeChangeDate": "2017:09:28 19:34:19+02:00",
  "FilePermissions": "rw-r--r--",
  "FileType": "JPEG",
  "FileTypeExtension": "jpg",
  "MIMEType": "image/jpeg",
  "JFIFVersion": 1.01,
  "ResolutionUnit": "inches",
  "XResolution": 72,
  "YResolution": 72,
  "ImageWidth": 3840,
  "ImageHeight": 6000,
  "EncodingProcess": "Baseline DCT, Huffman coding",
  "BitsPerSample": 8,
  "ColorComponents": 3,
  "YCbCrSubSampling": "YCbCr4:4:4 (1 1)",
  "ImageSize": "3840x6000",
  "Megapixels": 23.0
}]

[laino]

Values will still need sanitation though. Exiftool likes to append spaces to the end of values for example.