OCR: Tesseract 4.1.1 / Ghostscript 9.54.0

With tesseract v4.0.0-beta.3 we often observe crashes with:

```
contains_unichar_id(unichar_id):Error:Assert failed:in file ../../src/ccutil/unicharset.h, line 511
```

This seems to have been fixed by tesseract-ocr/tesseract#1954

Still, even after updating to 4.1.1, text recognition from PDF in ERP5 is too expensive. We also update Ghostscript to 9.54.0, because this version has built-in OCR, which does not need to convert the PDF to PNG then TIFF as we currently do in ERP5.

See merge request nexedi/slapos!985

component/ghostscript/buildout.cfg

@@ -2,36 +2,41 @@
 extends =
   ../fontconfig/buildout.cfg
   ../freetype/buildout.cfg
+  ../libjpeg/buildout.cfg
   ../libtiff/buildout.cfg
   ../libxml2/buildout.cfg
   ../pkgconfig/buildout.cfg
+  ../tesseract/buildout.cfg
   ../xz-utils/buildout.cfg
 
 parts = ghostscript
 
-[ghostscript-common]
+[ghostscript]
 recipe = slapos.recipe.cmmi
 shared = true
-pkg_config_depends = ${libtiff:location}/lib/pkgconfig:${fontconfig:location}/lib/pkgconfig:${fontconfig:pkg_config_depends}
+url = https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/download/gs9540/ghostscript-9.54.0.tar.gz
+md5sum = 5d571792a8eb826c9f618fb69918d9fc
+pkg_config_depends = ${libtiff:location}/lib/pkgconfig:${libjpeg:location}/lib/pkgconfig:${fontconfig:location}/lib/pkgconfig:${fontconfig:pkg_config_depends}
+# XXX --with-tessdata work arounds a slaprunner bug of having softwares installed in a path containing //
 configure-options =
   --disable-cups
   --disable-threadsafe
   --with-system-libtiff
   --without-libidn
   --without-x
   --with-drivers=FILES
-# it seems that parallel build sometimes fails for ghostscript.
-make-options = -j1
+  --with-tessdata=$(python -c 'print("""${:tessdata-location}""".replace("//", "/"))')
 environment =
   PATH=${pkgconfig:location}/bin:${xz-utils:location}/bin:%(PATH)s
   PKG_CONFIG_PATH=${:pkg_config_depends}
-  LDFLAGS=-Wl,-rpath=${fontconfig:location}/lib -Wl,-rpath=${freetype:location}/lib -Wl,-rpath=${libtiff:location}/lib
+  CFLAGS=-I${libjpeg:location}/include
+  LDFLAGS=-Wl,-rpath=${fontconfig:location}/lib -Wl,-rpath=${freetype:location}/lib -Wl,-rpath=${libtiff:location}/lib -L${libjpeg:location}/lib -Wl,-rpath=${libjpeg:location}/lib
   LD_LIBRARY_PATH=${fontconfig:location}/lib:${freetype:location}/lib:${libtiff:location}/lib:${libxml2:location}/lib
 
-[ghostscript]
-<= ghostscript-9
+# configure gives priority to local jpeg library and refuse mixing local libjpeg with "system" libtiff.
+# We remove this local jpeg library source folder so that configure picks up the slapos versions of these libraries.
+pre-configure = rm -r jpeg
 
-[ghostscript-9]
-<= ghostscript-common
-url = https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/download/gs950/ghostscript-9.50.tar.xz
-md5sum = 6cea6bae4a7cdfac6ccb09f07f0caf8c
+post-make-hook = ${tesseract-download-traineddata:post-make-hook}
+tessdata-location = @@LOCATION@@/share/tessdata/
+tessdata-urls = ${tesseract-download-traineddata:urls}

component/leptonica/buildout.cfg

@@ -7,17 +7,14 @@ extends =
   ../libtiff/buildout.cfg
   ../webp/buildout.cfg
   ../giflib/buildout.cfg
-  ../patch/buildout.cfg
 
 [leptonica]
 recipe = slapos.recipe.cmmi
-url = http://www.leptonica.com/source/leptonica-1.76.0.tar.gz
-md5sum = a263a5e4f7e8f8a661fb121a265d2d20
 shared = true
+url = http://www.leptonica.org/source/leptonica-1.80.0.tar.gz
+md5sum = d640d684234442a84c9e8902f0b3ff36
 configure-options =
   --disable-static
-
 environment =
   CPPFLAGS=-I${zlib:location}/include -I${libjpeg:location}/include -I${libpng:location}/include -I${libtiff:location}/include -I${webp:location}/include -I${giflib:location}/include
   LDFLAGS=-L${zlib:location}/lib -Wl,-rpath=${zlib:location}/lib -L${libjpeg:location}/lib -Wl,-rpath=${libjpeg:location}/lib -L${libpng:location}/lib -Wl,-rpath=${libpng:location}/lib -L${libtiff:location}/lib -Wl,-rpath=${libtiff:location}/lib -L${webp:location}/lib -Wl,-rpath=${webp:location}/lib -L${giflib:location}/lib -Wl,-rpath=${giflib:location}/lib
-  PATH=${patch:location}/bin:%(PATH)s

component/tesseract/buildout.cfg

@@ -10,43 +10,34 @@ extends =
   ../fontconfig/buildout.cfg
   ../lcms/buildout.cfg
   ../pkgconfig/buildout.cfg
-
+  ./buildout.hash.cfg
 parts =
   tesseract
-  tesseract-traineddata
-  tesseract-eng-traineddata
-  tesseract-osd-traineddata
 
 [tesseract]
 recipe = slapos.recipe.cmmi
-url = https://github.com/tesseract-ocr/tesseract/archive/6b250b58121a9858d3e3019a78a6f7d421bd0fc7.tar.gz
-md5sum = fdc38148ad8eb1bd0485a217503dd6d5
+shared = true
+url = https://github.com/tesseract-ocr/tesseract/archive/refs/tags/4.1.1.tar.gz
+md5sum = 51fe2bcbff1bbce77a25d180fd247f7d
 pkg_config_depends = ${leptonica:location}/lib/pkgconfig:${fontconfig:location}/lib/pkgconfig:${fontconfig:pkg_config_depends}:${lcms2:location}/lib/pkgconfig:${xz-utils:location}/lib/pkgconfig
 pre-configure =
   autoreconf -ivf -I${pkgconfig:location}/share/aclocal -I${libtool:location}/share/aclocal -Wno-portability
 
-configure-options =
-  --disable-static
-  --datarootdir=${tesseract-traineddata:location}
-# XXX: tesseract seems not easily configurable at runtime about where to find
-# its trained data, so we set its datarootdir above to a controlled location
-
 environment =
   PATH=${pkgconfig:location}/bin:${autoconf:location}/bin:${automake:location}/bin:${libtool:location}/bin:${m4:location}/bin:${patch:location}/bin:%(PATH)s
   PKG_CONFIG_PATH=${:pkg_config_depends}
   LDFLAGS=-L${leptonica:location}/lib -Wl,-rpath=${leptonica:location}/lib -L${jbigkit:location}/lib -Wl,-rpath=${jbigkit:location}/lib -L${zlib:location}/lib -Wl,-rpath=${zlib:location}/lib
 
-[tesseract-traineddata]
-location = ${buildout:parts-directory}/${:_buildout_section_name_}
+post-make-hook = ${tesseract-download-traineddata:post-make-hook}
+tessdata-urls = ${tesseract-download-traineddata:urls}
+tessdata-location = @@LOCATION@@/share/tessdata/
 
-[tesseract-eng-traineddata]
-recipe = slapos.recipe.build:download
-destination = ${tesseract-traineddata:location}/tessdata/eng.traineddata
-url = https://github.com/tesseract-ocr/tessdata/raw/590567f20dc044f6948a8e2c61afc714c360ad0e/eng.traineddata
-md5sum = 57e0df3d84fed9fbf8c7a8e589f8f012
 
-[tesseract-osd-traineddata]
-recipe = slapos.recipe.build:download
-destination = ${tesseract-traineddata:location}/tessdata/osd.traineddata
-url = https://github.com/tesseract-ocr/tessdata/raw/590567f20dc044f6948a8e2c61afc714c360ad0e/osd.traineddata
-md5sum = 7611737524efd1ce2dde67eff629bbcf
+[tesseract-download-traineddata]
+post-make-hook = ${:_profile_base_location_}/${download-tessdata.py:filename}#${download-tessdata.py:md5sum}:post_make_hook
+urls =
+    https://raw.githubusercontent.com/tesseract-ocr/tessdata/4.1.0/eng.traineddata#57e0df3d84fed9fbf8c7a8e589f8f012
+    https://raw.githubusercontent.com/tesseract-ocr/tessdata/4.1.0/osd.traineddata#7611737524efd1ce2dde67eff629bbcf
+    https://raw.githubusercontent.com/tesseract-ocr/tessdata/4.1.0/fra.traineddata#a73e70c872f262895d93976febeb1638
+    https://raw.githubusercontent.com/tesseract-ocr/tessdata/4.1.0/jpn.traineddata#af3a30a9bec904e106aa8521e7caaeca
+    https://raw.githubusercontent.com/tesseract-ocr/tessdata/4.1.0/chi_sim.traineddata#6965cb3213edd961cb16264e2ea45f5c

component/tesseract/buildout.hash.cfg

@@ -0,0 +1,3 @@
+[download-tessdata.py]
+filename = download-tessdata.py
+md5sum = 2d283a6d8662d6bb8c9de7b26162b702

component/tesseract/download-tessdata.py

@@ -0,0 +1,27 @@
+# This is a post-make hook script to download tesseract training data.
+#
+# This script uses the following buildout options:
+#   - tessdata-urls: list of URLs and their expected md5sum as URL fragments
+#   - tessdata-location: path where to install the data.
+
+import zc.buildout
+import os
+
+
+def post_make_hook(options, buildout, env):
+  if not os.path.exists(options['tessdata-location']):
+    os.makedirs(options['tessdata-location'])
+
+  download = zc.buildout.download.Download(
+      buildout['buildout'],
+      hash_name=True,
+  )
+  for url in options['tessdata-urls'].splitlines():
+    url, _, md5sum = url.partition('#')
+    if url:
+      download(
+          url,
+          md5sum=md5sum,
+          path=os.path.join(options['tessdata-location'],
+                            os.path.basename(url)),
+      )

stack/erp5/buildout.cfg

@@ -7,6 +7,7 @@ extends =
   buildout.hash.cfg
   ../../component/fonts/buildout.cfg
   ../../component/git/buildout.cfg
+  ../../component/ghostscript/buildout.cfg
   ../../component/graphviz/buildout.cfg
   ../../component/gzip/buildout.cfg
   ../../component/xz-utils/buildout.cfg
@@ -65,8 +66,6 @@ parts +=
   slapos-cookbook
   mroonga-mariadb
   tesseract
-  tesseract-eng-traineddata
-  tesseract-osd-traineddata
   zabbix-agent
 
 # Buildoutish
@@ -252,6 +251,7 @@ link-binary =
   ${graphviz:location}/bin/dot
   ${grep:location}/bin/grep
   ${imagemagick:location}/bin/convert
+  ${ghostscript:location}/bin/gs
   ${imagemagick:location}/bin/identify
   ${jpegoptim:location}/bin/jpegoptim
   ${jsl:location}/bin/jsl