Module: Pdf2MarkdownOCR::Pdf2Image

Defined in:
lib/pdf2markdownOCR/pdf2image.rb

Class Method Summary collapse

Class Method Details

.multi_thread_conversion(pdf_path:, output_prefix:, pages: nil) ⇒ Object 



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# File 'lib/pdf2markdownOCR/pdf2image.rb', line 46

def self.multi_thread_conversion(pdf_path:, output_prefix:, pages: nil)

  Pdf2MarkdownOCR.configuration.logger.info "Converting #{pdf_path} into images. DPI: #{Pdf2MarkdownOCR.configuration.png_dpi_resolution}"
 
  pages_to_process = []
  if pages.nil?
    info = Terrapin::CommandLine.new("pdfinfo", pdf_path).run
    total_pages = info.match(/^Pages:\s+(\d+)/)[1].to_i
    pages_to_process = (1..total_pages).to_a
  else
    pages.split(",").each do |page_range|
      if page_range.include?("-")
        start_page, end_page = page_range.split("-").map(&:to_i)
        pages_to_process += (start_page..end_page).to_a
      else
        pages_to_process << page_range.to_i
      end
    end
  end
  
  Pdf2MarkdownOCR.configuration.logger.info "Total pages to process: #{pages_to_process.size}"
  t1 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
  threads = pages_to_process.map do |page|
    Thread.new do
      Terrapin::CommandLine.new(
        "pdftoppm",
        "-png -r #{Pdf2MarkdownOCR.configuration.png_dpi_resolution} -f #{page} -l #{page} #{pdf_path} #{output_prefix}/pdf2ocr"
      ).run

      Pdf2MarkdownOCR.configuration.logger.info "Converted page #{page}/#{pages_to_process.size}"
    end
  end

  threads.each(&:join)
  t2 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
  Pdf2MarkdownOCR.configuration.logger.info "PDF to image conversion time: #{(t2 - t1).round(2)} seconds"

  Dir.glob("#{output_prefix}/pdf2ocr*.png").sort
end

.single_thread_conversion(pdf_path:, output_prefix:, pages: nil) ⇒ Object 



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# File 'lib/pdf2markdownOCR/pdf2image.rb', line 7

def self.single_thread_conversion(pdf_path:, output_prefix:, pages: nil)
  Pdf2MarkdownOCR.configuration.logger.info "Converting #{pdf_path} into images. DPI: #{Pdf2MarkdownOCR.configuration.png_dpi_resolution}"
  
  t1 = Process.clock_gettime(Process::CLOCK_MONOTONIC)

  if pages.nil?
    line = Terrapin::CommandLine.new(
      "pdftoppm",
      "-png -r #{Pdf2MarkdownOCR.configuration.png_dpi_resolution} #{pdf_path} #{output_prefix}/pdf2ocr"
    )
    line.run
  else
    pages.split(",").each do |page_range|
      if page_range.include?("-")
        start_page, end_page = page_range.split("-").map(&:to_i)
        line = Terrapin::CommandLine.new(
          "pdftoppm",
          "-png -r #{Pdf2MarkdownOCR.configuration.png_dpi_resolution}" +
          " -f #{start_page} -l #{end_page}" + 
          " #{pdf_path} #{output_prefix}/pdf2ocr"
        )
        line.run
      else
        line = Terrapin::CommandLine.new(
          "pdftoppm",
          "-png -r #{Pdf2MarkdownOCR.configuration.png_dpi_resolution}" +
          " -f #{page_range} -l #{page_range}" + 
          " #{pdf_path} #{output_prefix}/pdf2ocr"
        )
        line.run
      end
    end
  end

  t2 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
  Pdf2MarkdownOCR.configuration.logger.info "PDF to image conversion time: #{(t2 - t1).round(2)} seconds"
  Dir.glob("#{output_prefix}/pdf2ocr*.png").sort
end