Class: RTesseract

Inherits:
Object
  • Object
show all
Defined in:
lib/rtesseract.rb,
lib/rtesseract/mixed.rb,
lib/rtesseract/errors.rb

Defined Under Namespace

Classes: ConversionError, ImageNotSelectedError, Mixed, TempFilesNotRemovedError

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(src = "", options = {}) ⇒ RTesseract

Returns a new instance of RTesseract.



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# File 'lib/rtesseract.rb', line 13

def initialize(src = "", options = {})
  @command = options.delete(:command) || default_command
  @lang    = options.delete(:lang)    || options.delete("lang") || ""
  @psm     = options.delete(:psm)     || options.delete("psm")  || nil
  @clear_console_output = options.delete(:clear_console_output)
  @clear_console_output = true if @clear_console_output.nil?
  @options = options
  @value   = ""
  @x, @y, @w, @h = []
  @processor = options.delete(:processor) || options.delete("processor")
  choose_processor!
  if is_a_instance?(src)
    @source = Pathname.new '.'
    @instance = src
  else
    @instance = nil
    @source  = Pathname.new src
  end
end

Instance Attribute Details

#lang ⇒ Object

Select the language

Languages

  • eng - English

  • deu - German

  • deu-f - German fraktur

  • fra - French

  • ita - Italian

  • nld - Dutch

  • por - Portuguese

  • spa - Spanish

  • vie - Vietnamese

Note: Make sure you have installed the language to tesseract



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# File 'lib/rtesseract.rb', line 92

def lang
  language = "#{@lang}".strip.downcase
  { #Aliases to languages names
    "eng" => ["en","en-us","english"],
    "ita" => ["it"],
    "por" => ["pt","pt-br","portuguese"],
    "spa" => ["sp"]
  }.each do |value,names|
    return " -l #{value} " if names.include? language
  end
  return " -l #{language} " if language.size > 0
  ""
rescue
  ""
end

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/rtesseract.rb', line 8

def options
  @options
end

#processor ⇒ Object (readonly)

Returns the value of attribute processor.



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# File 'lib/rtesseract.rb', line 11

def processor
  @processor
end

#psm ⇒ Object

Page Segment Mode



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# File 'lib/rtesseract.rb', line 109

def psm
  @psm.nil? ? "" : " -psm #{@psm} "
rescue
  ""
end

Class Method Details

.read(src = nil, options = {}) {|image| ... } ⇒ Object

Yields:

  • (image)

Raises:



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# File 'lib/rtesseract.rb', line 39

def self.read(src = nil, options = {}, &block)
  raise RTesseract::ImageNotSelectedError if src == nil
  processor = options.delete(:processor) || options.delete("processor")
  if processor == "mini_magick"
    image = MiniMagickProcessor.read_with_processor(src.to_s)
  else
    image = RMagickProcessor.read_with_processor(src.to_s)
  end
  yield image
  object = RTesseract.new("", options)
  object.from_blob(image.to_blob)
  object
end

Instance Method Details

#clear_console_output ⇒ Object

TODO: Clear console for MacOS or Windows



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# File 'lib/rtesseract.rb', line 129

def clear_console_output
  return "" unless @clear_console_output
  return "2>/dev/null" if File.exist?("/dev/null") #Linux console clear
end

#config ⇒ Object 



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# File 'lib/rtesseract.rb', line 115

def config
  @options ||= {}
  @options.collect{|k,v| "#{k} #{v}" }.join("\n")
end

#config_file ⇒ Object 



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# File 'lib/rtesseract.rb', line 120

def config_file
  return "" if @options == {}
  conf = Tempfile.new("config")
  conf.write(config)
  conf.flush
  conf.path
end

#convert ⇒ Object

Convert image to string



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# File 'lib/rtesseract.rb', line 135

def convert
  path = Tempfile.new(["",".txt"]).path.to_s
  tmp_image = image_to_tiff
  `#{@command} "#{tmp_image.path}" "#{path.gsub(".txt","")}" #{lang} #{psm} #{config_file} #{clear_console_output}`
  @value = File.read("#{path}").to_s
  remove_file([tmp_image])
rescue
  raise RTesseract::ConversionError
end

#crop!(x, y, width, height) ⇒ Object

Crop image to convert



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# File 'lib/rtesseract.rb', line 64

def crop!(x,y,width,height)
  @x, @y, @w, @h = x, y, width, height
  self
end

#default_command ⇒ Object 



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# File 'lib/rtesseract.rb', line 33

def default_command
  TesseractBin::Executables[:tesseract] || 'tesseract'
rescue
  "tesseract"
end

#from_blob(blob) ⇒ Object

Read image from memory blob



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# File 'lib/rtesseract.rb', line 146

def from_blob(blob)
  blob_file = Tempfile.new("blob")
  blob_file.write(blob)
  blob_file.rewind
  blob_file.flush
  self.source = blob_file.path
  convert
  remove_file([blob_file])
rescue
  raise RTesseract::ConversionError
end

#image_name ⇒ Object 



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# File 'lib/rtesseract.rb', line 58

def image_name
  @source.basename
end

#remove_file(files = []) ⇒ Object

Remove files



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# File 'lib/rtesseract.rb', line 70

def remove_file(files=[])
  files.each do |file|
    file.close
    file.unlink
  end
  true
rescue
  raise RTesseract::TempFilesNotRemovedError
end

#source=(src) ⇒ Object 



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# File 'lib/rtesseract.rb', line 53

def source= src
  @value = ""
  @source = Pathname.new src
end

#to_s ⇒ Object

Output value



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# File 'lib/rtesseract.rb', line 159

def to_s
  return @value if @value != ""
  if @source.file? || @instance.present?
    convert
    @value
  else
    raise RTesseract::ImageNotSelectedError
  end
end

#to_s_without_spaces ⇒ Object

Remove spaces and break-lines



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# File 'lib/rtesseract.rb', line 170

def to_s_without_spaces
  to_s.gsub(" ","").gsub("\n","").gsub("\r","")
end