Module: Metaclean::Strategy

Defined in:
lib/metaclean/strategy.rb

Constant Summary collapse

PRIVACY_GROUP_PREFIXES = 
%w[GPS XMP- MakerNotes IPTC IFD1].freeze
MAT2_ESSENTIAL = 
%w[
  docx xlsx pptx odt ods odp odg odf odc odi epub
  zip tar torrent html htm xhtml xht ncx
].freeze
PRIVACY_TAGS = 
%w[
  Artist Author Creator Copyright Rights
  By-line By-lineTitle Credit Source Contact OwnerName
  CameraOwnerName SerialNumber InternalSerialNumber LensSerialNumber
  CameraSerialNumber UniqueCameraModel LocalizedCameraModel
  RawDataUniqueID OriginalRawFileName OriginalRawFileData
  OriginalRawFileDigest RawImageDigest NewRawImageDigest
  CameraCalibrationSignature ProfileCalibrationSignature
  ProfileName ProfileCopyright AsShotProfileName
  Software HostComputer ProcessingSoftware
  ImageDescription UserComment
  LastModifiedBy LastSavedBy LastAuthor
  Make Model LensModel DateTimeOriginal CreateDate
  Title Subject Keywords Description Category Producer Company Manager
  CreationDate ModDate
  XPAuthor XPComment XPSubject XPKeywords XPTitle Comment
].freeze
MAT2_PREFERRED = 
%w[
  docx xlsx pptx odt ods odp odg odf odc odi epub png svg svgz
  mp4 avi
].freeze
RESIDUAL_IGNORED_GROUPS = 
%w[System ExifTool Composite].freeze
ICC_PRIVACY_TAGS = 
%w[
  ProfileDescription ProfileDescriptionML ProfileCopyright ProfileCreator
  ProfileCMMType DeviceManufacturer DeviceModel DeviceMfgDesc DeviceModelDesc
].freeze
ICC_STANDARD_DESCRIPTIONS = 
[
  'srgb iec61966-2.1', 'srgb', 'srgb iec61966-2-1 black scaled',
  'srgb iec61966-2-1 no black scaling', 'display p3', 'dci-p3', 'p3-d65 (display)',
  'adobe rgb (1998)', 'prophoto rgb', 'romm rgb: iso 22028-2:2013',
  'apple rgb', 'colormatch rgb', 'camera rgb profile',
  'apple wide color sharing profile', 'linear rgb profile',
  'generic rgb profile', 'generic gray profile', 'generic gray gamma 2.2 profile',
  'generic lab profile', 'generic cmyk profile', 'generic xyz profile',
  'gray gamma 2.2', 'dot gain 20%',
  'rec. itu-r bt.709-5', 'hdtv (rec. 709)', 'sdtv (rec. 601)'
].freeze
FFMPEG_FORMATS = 
%w[mkv webm].freeze
MAT2_DEGRADES = 
%w[jpg jpe jpeg webp tif tiff heic].freeze

Class Method Summary collapse

Class Method Details

.blank_value?(value) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/metaclean/strategy.rb', line 127

def blank_value?(value)
  s = value.to_s
  s.strip.empty? || s.gsub(/[Z0\s:.+-]/, '').empty?
end

.date_like_tag?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/metaclean/strategy.rb', line 122

def date_like_tag?(name)
  n = name.to_s
  n.end_with?('Date') || n.start_with?('DateTime')
end

.exempt_blank?(name, value) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/metaclean/strategy.rb', line 116

def exempt_blank?(name, value)
  return true if value.to_s.strip.empty?

  date_like_tag?(name) && blank_value?(value)
end

.mat2_essential?(path) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/metaclean/strategy.rb', line 146

def mat2_essential?(path)
  MAT2_ESSENTIAL.include?(Metaclean.ext_of(path))
end

.normalize_icc_value(value) ⇒ Object 



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# File 'lib/metaclean/strategy.rb', line 112

def normalize_icc_value(value)
  value.to_s.strip.downcase.gsub(/\s+/, ' ')
end

.privacy_group?(group) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/metaclean/strategy.rb', line 132

def privacy_group?(group)
  PRIVACY_GROUP_PREFIXES.any? { |p| group.to_s.start_with?(p) }
end

.privacy_residual(meta, allow_icc_metadata: false) ⇒ Object 



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# File 'lib/metaclean/strategy.rb', line 80

def privacy_residual(meta, allow_icc_metadata: false)
  standard_icc = standard_icc_profile?(meta)
  meta.select do |k, v|
    key = k.to_s
    next false if key == 'SourceFile'

    group, tag = key.split(':', 2)
    name = tag.nil? ? group.to_s : tag
    next false if RESIDUAL_IGNORED_GROUPS.include?(group.to_s)

    icc_privacy = group.to_s.start_with?('ICC') && ICC_PRIVACY_TAGS.include?(name)
    if group.to_s.start_with?('ICC')
      next false if allow_icc_metadata || standard_icc
      next false unless icc_privacy
    end

    gps = group.to_s.start_with?('GPS') || name.start_with?('GPS')
    next false if !gps && exempt_blank?(name, v)

    icc_privacy || privacy_group?(group) || privacy_tag?(name)
  end
end

.privacy_tag?(tag) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/metaclean/strategy.rb', line 136

def privacy_tag?(tag)
  t = tag.to_s
  return true if PRIVACY_TAGS.include?(t) || t.start_with?('GPS')
  return true if t.match?(/SerialNumber\z/i)
  return true if t.match?(/\AOriginalRawFile(?:Name|Data|Digest)\z/i)
  return true if t.match?(/\A(?:RawDataUniqueID|RawImageDigest|NewRawImageDigest)\z/i)

  false
end

.standard_icc_profile?(meta) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/metaclean/strategy.rb', line 103

def standard_icc_profile?(meta)
  meta.any? do |k, v|
    key = k.to_s
    next false unless key.start_with?('ICC') && key.split(':', 2).last == 'ProfileDescription'

    ICC_STANDARD_DESCRIPTIONS.include?(normalize_icc_value(v))
  end
end

.tools_for(path) ⇒ Object 



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# File 'lib/metaclean/strategy.rb', line 60

def tools_for(path)
  ext = Metaclean.ext_of(path)
  tools = []

  if ext == 'pdf'
    tools << :exiftool
    tools << :qpdf if Qpdf.available?
  elsif FFMPEG_FORMATS.include?(ext)
    tools << :ffmpeg if Ffmpeg.available?
  elsif MAT2_PREFERRED.include?(ext) && Mat2.available?
    tools << :mat2
    tools << :exiftool
  else
    tools << :exiftool
    tools << :mat2 if Mat2.supports?(path) && !MAT2_DEGRADES.include?(ext)
  end

  tools
end