Class: IiifPrint::JP2DerivativeService

Inherits:
BaseDerivativeService show all
Defined in:
lib/iiif_print/jp2_derivative_service.rb

Constant Summary collapse

CMD_GRAY =

OpenJPEG 2000 Command to make NDNP-compliant grayscale JP2:

'opj_compress -i %<source_file>s -o %<out_file>s ' \
'-d 0,0 -b 64,64 -n 6 -p RLCP -t 1024,1024 -I -M 1 ' \
'-r 64,53.821,45.249,40,32,26.911,22.630,20,16,14.286,' \
'11.364,10,8,6.667,5.556,4.762,4,3.333,2.857,2.500,2,' \
'1.667,1.429,1.190,1'.freeze
CMD_COLOR =

OpenJPEG 2000 Command to make RGB JP2:

'opj_compress -i %<source_file>s -o %<out_file>s ' \
'-d 0,0 -b 64,64 -n 6 -p RPCL -t 1024,1024 -I -M 1 '\
'-r 2.4,1.48331273,.91673033,.56657224,.35016049,.21641118,' \
'.13374944,.0944,.08266171'.freeze
CMD_1X =

OpenJPEG 1.x command replacement for 2.x opj_compress, takes same options;

this is necessary on Ubuntu Trusty (e.g. Travis CI)

'image_to_j2k'.freeze

Instance Attribute Summary collapse

Attributes inherited from BaseDerivativeService

#master_format

Instance Method Summary collapse

Methods inherited from BaseDerivativeService

#cleanup_derivatives, #convert_cmd, #derivative_path_factory, #identify, #im_convert, #jp2_convert, #jp2_to_intermediate, #load_destpath, #mime_type, #mime_type_for, #one_bit?, #prepare_path, #use_color?, #valid?

Constructor Details

#initialize(file_set) ⇒ JP2DerivativeService

Returns a new instance of JP2DerivativeService.



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# File 'lib/iiif_print/jp2_derivative_service.rb', line 28

def initialize(file_set)
  # cached result string for imagemagick `identify` command
  @command = nil
  @unlink_after_creation = []
  super(file_set)
end

Instance Attribute Details

#file_set ⇒ Object (readonly)

Returns the value of attribute file_set.



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# File 'lib/iiif_print/jp2_derivative_service.rb', line 25

def file_set
  @file_set
end

Instance Method Details

#create_derivatives(filename) ⇒ Object 



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# File 'lib/iiif_print/jp2_derivative_service.rb', line 35

def create_derivatives(filename)
  # Base class takes care of loading @source_path, @dest_path
  super(filename)

  # no creation if jp2 master => deemed unnecessary/duplicative
  return if mime_type == 'image/jp2'

  # if we have a non-TIFF source, or a 1-bit monochrome source, we need
  #   to make a NetPBM-based intermediate (temporary) file for OpenJPEG
  #   to consume.
  needs_intermediate = !tiff_source? || one_bit?

  # We use either intermediate temp file, or temp symlink (to work
  #   around OpenJPEG 2000 file naming quirk).
  needs_intermediate ? make_intermediate_source : make_symlink

  # Get OpenJPEG command, rendered with source, destination, appropriate
  #   to either color or grayscale source
  render_cmd = opj_command

  # Run the generated command to make derivative file at @dest_path
  data = `#{render_cmd}`

  # Create Hyrax::FileMetadata object for the derivatives (if Valkyrie)
  IiifPrint.copy_derivatives_from_data_store(stream: data, directives: { url: file_set.id.to_s, container: 'service_file', mime_type: mime_type_for(target_extension) })

  # Clean up any intermediate files or symlinks used during creation
  cleanup_intermediate
end