Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add parallel processing to OCR text extraction of full documents #124

Open
wants to merge 2 commits into
base: master
Choose a base branch
from
Open

Add parallel processing to OCR text extraction of full documents #124

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
1f1ec93
Add parallel processing to OCR text extraction
Dec 18, 2014
7427d08
Add Parallel installation to documentation
Dec 18, 2014
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 5 additions & 0 deletions index.html
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -159,6 +159,11 @@ <h2 id="installation">Installation &amp; Dependencies</h2>
<tt>aptitude install libreoffice</tt><br />
On the Mac, download and install <a href="http://www.libreoffice.org/download">the latest release</a>.
</li>
<li>
(Optional) Install <a href="http://www.gnu.org/software/parallel/">Parallel</a>:<br>
<tt>[aptitude | port | brew] install parallel</tt><br>
Parallel speeds up OCR text extraction of documents by processing pages in parallel.
</li>
</ol>

<p><i>
Expand Down
8 changes: 4 additions & 4 deletions lib/docsplit.rb
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,11 +13,11 @@ module Docsplit
ESCAPED_ROOT = ESCAPE[ROOT]

METADATA_KEYS = [:author, :date, :creator, :keywords, :producer, :subject, :title, :length]

GM_FORMATS = ["image/gif", "image/jpeg", "image/png", "image/x-ms-bmp", "image/svg+xml", "image/tiff", "image/x-portable-bitmap", "application/postscript", "image/x-portable-pixmap"]

DEPENDENCIES = {:java => false, :gm => false, :pdftotext => false, :pdftk => false, :pdftailor => false, :tesseract => false, :osd => false}
GM_FORMATS = ["image/gif", "image/jpeg", "image/png", "image/x-ms-bmp", "image/svg+xml", "image/tiff", "image/x-portable-bitmap", "application/postscript", "image/x-portable-pixmap"]

DEPENDENCIES = {:java => false, :gm => false, :pdftotext => false, :pdftk => false, :pdftailor => false, :tesseract => false, :osd => false, :parallel => false}

# Check for all dependencies, and note their absence.
dirs = ENV['PATH'].split(File::PATH_SEPARATOR)
DEPENDENCIES.each_key do |dep|
Expand Down Expand Up @@ -75,7 +75,7 @@ def self.extract_#{key}(pdfs, opts={})
end
EOS
end

def self.extract_info(pdfs, opts={})
pdfs = ensure_pdfs(pdfs)
InfoExtractor.new.extract_all(pdfs, opts)
Expand Down
18 changes: 11 additions & 7 deletions lib/docsplit/text_extractor.rb
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -72,18 +72,22 @@ def extract_from_ocr(pdf, pages)
FileUtils.remove_entry_secure tiff
end
else
tiff = "#{tempdir}/#{@pdf_name}.tif"
escaped_tiff = ESCAPE[tiff]
run "MAGICK_TMPDIR=#{tempdir} OMP_NUM_THREADS=2 gm convert -despeckle #{MEMORY_ARGS} #{OCR_FLAGS} #{escaped_pdf} #{escaped_tiff} 2>&1"
#if the user says don't do orientation detection or the plugin is not installed, set psm to 0
run "tesseract #{escaped_tiff} #{base_path} -l #{@language} #{psm} 2>&1"
clean_text(base_path + '.txt') if @clean_ocr
if DEPENDENCIES[:parallel]
run "MAGICK_TMPDIR=#{tempdir} gm convert -despeckle +adjoin #{MEMORY_ARGS} #{OCR_FLAGS} #{escaped_pdf} #{tempdir}/page_%d.tiff 2>&1"
run "parallel tesseract -l #{@language} #{psm} {} {.} ::: #{tempdir}/page_*.tiff 2>&1"
run "cat #{tempdir}/page_*.txt >'#{base_path}.txt' 2>&1"
else
tiff = "#{tempdir}/#{@pdf_name}.tif"
escaped_tiff = ESCAPE[tiff]
run "MAGICK_TMPDIR=#{tempdir} OMP_NUM_THREADS=2 gm convert -despeckle #{MEMORY_ARGS} #{OCR_FLAGS} #{escaped_pdf} #{escaped_tiff} 2>&1"
run "tesseract #{escaped_tiff} #{base_path} -l #{@language} #{psm} 2>&1"
end
clean_text("#{base_path}.txt") if @clean_ocr
end
ensure
FileUtils.remove_entry_secure tempdir if File.exists?(tempdir)
end


private

def clean_text(file)
Expand Down