Module: JXL::Color::ICCProfile

Defined in:
lib/jxl/color/icc_profile.rb

Overview

rubocop:disable Metrics/ModuleLength

Constant Summary collapse

WHITE_POINTS = 
{ 1 => [0.3127, 0.3290], 10 => [1.0 / 3, 1.0 / 3], 11 => [0.314, 0.351] }.freeze
PRIMARIES = 
{
  1 => [[0.639998686, 0.330010138], [0.300003784, 0.600003357], [0.150002046, 0.059997204]],
  9 => [[0.708, 0.292], [0.170, 0.797], [0.131, 0.046]],
  11 => [[0.680, 0.320], [0.265, 0.690], [0.150, 0.060]]
}.freeze
BRADFORD = 
[[0.8951, 0.2664, -0.1614], [-0.7502, 1.7135, 0.0367],
[0.0389, -0.0685, 1.0296]].freeze
BRADFORD_INVERSE = 
[[0.9869929, -0.1470543, 0.1599627], [0.4323053, 0.5183603, 0.0492912],
[-0.0085287, 0.0400428, 0.9684867]].freeze
TRANSFER_NAMES = 
{ 1 => "709", 8 => "Lin", 13 => "SRG", 16 => "PQ", 17 => "DCI", 18 => "HLG" }.freeze
INTENT_NAMES = 
%w[Per Rel Sat Abs].freeze

Class Method Summary collapse

Class Method Details

.create(encoding) ⇒ Object

Raises:



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# File 'lib/jxl/color/icc_profile.rb', line 23

def create(encoding)
  raise UnsupportedFeatureError, "ICC profile for embedded encoding" if encoding.want_icc
  unless [0, 1].include?(encoding.colour_space)
    raise UnsupportedFeatureError, "ICC profile colour space #{encoding.colour_space}"
  end

  white = encoding.white_point == 2 ? encoding.white_point_xy : WHITE_POINTS.fetch(encoding.white_point)
  primaries = if encoding.colour_space == 1
                PRIMARIES[1]
              elsif encoding.primaries == 2
                encoding.primaries_xy
              else
                PRIMARIES.fetch(encoding.primaries)
              end
  raise CorruptError, "missing custom ICC white point" unless white
  raise CorruptError, "missing custom ICC primaries" unless primaries

  header = create_header(encoding)
  table = +"\0\0\0\0".b
  tags = +"".b
  entries = []
  add_tag!(entries, tags, "desc", mluc(description(encoding)))
  add_tag!(entries, tags, "cprt", mluc("CC0"))
  white_xyz = encoding.colour_space == 1 ? xy_to_xyz(white) : [0.964203, 1.0, 0.824905]
  add_tag!(entries, tags, "wtpt", xyz_tag(white_xyz))
  if encoding.colour_space.zero?
    adaptation = adapt_to_d50(white)
    add_tag!(entries, tags, "chad", fixed_tag("sf32", adaptation.flatten))
    add_cicp!(entries, tags, encoding)
    rgb_matrix(primaries, white).transpose.each_with_index do |column, index|
      add_tag!(entries, tags, %w[rXYZ gXYZ bXYZ][index], xyz_tag(column))
    end
  end
  trc_offset = tags.bytesize
  trc = transfer_tag(encoding)
  tags << trc << ("\0" * ((-trc.bytesize) & 3))
  trc_names = encoding.colour_space == 1 ? ["kTRC"] : %w[rTRC gTRC bTRC]
  trc_names.each { entries << [_1, trc_offset, tags.bytesize - trc_offset] }

  table[0, 4] = [entries.length].pack("N")
  base = header.bytesize + 4 + (entries.length * 12)
  entries.each { |name, offset, size| table << name << [base + offset, size].pack("N2") }
  profile = header + table + tags
  profile[0, 4] = [profile.bytesize].pack("N")
  checksum = profile.dup
  checksum[44, 4] = checksum[64, 4] = "\0" * 4
  profile[84, 16] = Digest::MD5.digest(checksum)
  profile
end