Class: Kithe::ExiftoolCharacterization::Result

Inherits:
Object
  • Object
show all
Defined in:
app/characterization/kithe/exiftool_characterization/result.rb

Overview

Retrieve known info out of exiftool results.

It can be really tricky to get this reliably from arbitrary files/cameras, there’s a lot of variety in EXIF/XMP/etc use.

We also normalize exiftool validation warnings in #exiftool_validation_warnings, they’re kind of a pain to extract

We do this right now for our use cases, in terms of what data we want, and what is actually found in ours. PR’s welcome to generalize!

In the future, we might have different result classes for different versions of exiftool or ways of calling it, it’s best to instantiate this with:

result = Kithe::ExiftoolChacterization.presenter(some_result_hash)
result.camera_model
result.exiftool_validation_warnings

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(hash) ⇒ Result

Returns a new instance of Result.



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 23

def initialize(hash)
  @result = hash || {}
end

Instance Attribute Details

#result ⇒ Object (readonly)

Returns the value of attribute result.



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 21

def result
  @result
end

Instance Method Details

#bits_per_sample ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 35

def bits_per_sample
  result["EXIF:BitsPerSample"]
end

#camera_iso ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 79

def camera_iso
  result["EXIF:ISO"]
end

#camera_lens ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 71

def camera_lens
  result["XMP:Lens"]
end

#camera_make ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 47

def camera_make
  result["EXIF:Make"]
end

#camera_model ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 51

def camera_model
  result["EXIF:Model"]
end

#compression ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 43

def compression
  result["EXIF:Compression"]
end

#creation_date ⇒ Object

We look in a few places, and we only return date not time because getting timezone info is unusual, and it’s all we need right now.

Returns:

  • Date



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 99

def creation_date
  str_date = result["EXIF:DateTimeOriginal"] || result["EXIF:DateTimeOriginal"] || result["XMP:DateCreated"]
  return nil unless str_date

  Date.strptime(str_date, '%Y:%m:%d')
rescue Date::Error
  return nil
end

#dpi ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 55

def dpi
  # only "dpi" if unit is inches
  return nil unless result["EXIF:ResolutionUnit"] == "inches"

  if result["EXIF:XResolution"] == result["EXIF:YResolution"]
    result["EXIF:XResolution"]
  else
    # for now, we bail on complicated case
    nil
  end
end

#exif_tool_args ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 31

def exif_tool_args
  result["Kithe:CliArgs"]
end

#exiftool_validation_warnings ⇒ Object

Multiple exiftool validation warnings are annoyingly in keys ‘ExifTool:Warning`, `ExifTool:Copy1:Warning`, `ExifTool:Copy2:Warning`, etc. We provide a convenience method to fetch em all and return them as an array.



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 113

def exiftool_validation_warnings
  @exiftool_validation_warnings ||= result.slice( *result.keys.grep(/ExifTool(:Copy\d+):Warning/) ).values
end

#exiftool_version ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 27

def exiftool_version
  result["ExifTool:ExifToolVersion"]
end

#icc_profile_name ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 83

def icc_profile_name
  result["ICC_Profile:ProfileDescription"]
end

#page_count ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 91

def page_count
  result["PDF:PageCount"]
end

#pdf_version ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 87

def pdf_version
  result["PDF:PDFVersion"]
end

#photometric_interpretation ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 39

def photometric_interpretation
  result["EXIF:PhotometricInterpretation"]
end

#shutter_speed ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 75

def shutter_speed
  result["Composite:ShutterSpeed"]
end

#software ⇒ Object 



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# File 'app/characterization/kithe/exiftool_characterization/result.rb', line 67

def software
  result["XMP:CreatorTool"]
end