Class: IiifPrint::TIFFDerivativeService

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

Constant Summary collapse

GRAY_CMD =

For imagemagick commands, the output type is determined by the

output file's extension.

TIFF (LZW, 8 bit grayscale)

'convert %<source_file>s ' \
'-depth 8 -colorspace Gray ' \
'-compress lzw %<out_file>s'.freeze
MONO_CMD =

Monochrome one-bit black/white TIFF, Group 4 compressed:

'convert %<source_file>s ' \
'-depth 1 -monochrome -compress Group4 -type bilevel ' \
'%<out_file>s'.freeze
COLOR_CMD =

sRBG color TIFF (8 bits per channel, lzw)

'convert %<source_file>s ' \
'-depth 24 ' \
'-compress lzw %<out_file>s'.freeze

Instance Attribute Summary

Attributes inherited from BaseDerivativeService

#file_set, #master_format

Instance Method Summary collapse

Methods inherited from BaseDerivativeService

#cleanup_derivatives, #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) ⇒ TIFFDerivativeService

Returns a new instance of TIFFDerivativeService.



24
25
26
 
# File 'lib/iiif_print/tiff_derivative_service.rb', line 24

def initialize(file_set)
  super(file_set)
end

Instance Method Details

#convert_cmd ⇒ Object

Get conversion command; command varies on whether or not we have

JP2 source, and whether we have color or grayscale material.



30
31
32
33
34
35
36
37
38
 
# File 'lib/iiif_print/tiff_derivative_service.rb', line 30

def convert_cmd
  source_path = @source_path
  source_path += '[0]' if @source_path.ends_with?('pdf')
  template = use_color? ? COLOR_CMD : GRAY_CMD
  template = MONO_CMD if one_bit?
  data = format(template, source_file: source_path, out_file: @dest_path)
  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) })
  data
end

#create_derivatives(filename) ⇒ Object 



40
41
42
43
44
45
46
47
48
49
50
 
# File 'lib/iiif_print/tiff_derivative_service.rb', line 40

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

  # no creation of TIFF deriviative if primary is TIFF
  return if mime_type == 'image/tiff'

  return jp2_convert if mime_type == 'image/jp2'
  # Otherwise, get, run imagemagick command to convert
  im_convert
end