tesseract_noop: begin implementing with plugin

2020-06-01 02:45:49 -07:00
parent 6528234608
commit 2b23f7ec73
3 changed files with 133 additions and 15 deletions
@@ -220,8 +220,12 @@ def check_ocrmypdf(input_file, output_file, *args, env=None):
    _parser, options, plugin_manager = get_parser_options_plugins(args=args)
    api.check_options(options, plugin_manager)
    if env:
-        options.tesseract_env = env
-        options.tesseract_env['_OCRMYPDF_TEST_INFILE'] = os.fspath(input_file)
+        first = env['_OCRMYPDF_TEST_PATH'].split(os.pathsep)[0]
+        if 'tesseract_noop' in first:
+            options.plugins = ['tests/plugins/tesseract_noop.py']
+        else:
+            options.tesseract_env = env
+            options.tesseract_env['_OCRMYPDF_TEST_INFILE'] = os.fspath(input_file)
    result = api.run_pipeline(options, plugin_manager=plugin_manager, api=True)

    assert result == 0
@@ -243,12 +247,19 @@ def run_ocrmypdf_api(input_file, output_file, *args, env=None):
    ]
    _parser, options, plugin_manager = get_parser_options_plugins(args=args)
    if env:
-        options.tesseract_env = env.copy()
-        options.tesseract_env['_OCRMYPDF_TEST_INFILE'] = os.fspath(input_file)
-        first_path = env.get('_OCRMYPDF_TEST_PATH', '').split(os.pathsep)[0]
-        if 'spoof' in first_path:
-            assert 'gs' not in first_path, "use run_ocrmypdf() for gs"
-            assert 'tesseract' in first_path
+        try:
+            first = env['_OCRMYPDF_TEST_PATH'].split(os.pathsep)[0]
+            if 'tesseract_noop' in first:
+                options.plugins = ['tests/plugins/tesseract_noop.py']
+            else:
+                options.tesseract_env = env.copy()
+                options.tesseract_env['_OCRMYPDF_TEST_INFILE'] = os.fspath(input_file)
+            first_path = env.get('_OCRMYPDF_TEST_PATH', '').split(os.pathsep)[0]
+            if 'spoof' in first_path:
+                assert 'gs' not in first_path, "use run_ocrmypdf() for gs"
+                assert 'tesseract' in first_path
+        except KeyError:
+            pass
    if options.tesseract_env:
        assert all(isinstance(v, (str, bytes)) for v in options.tesseract_env.values())

@@ -0,0 +1,111 @@
+#!/usr/bin/env python3
+# © 2016 James R. Barlow: github.com/jbarlow83
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+"""Tesseract no-op spoof
+
+To quickly run tests where getting OCR output is not necessary.
+
+In 'hocr' mode, create a .hocr file that specifies no text found.
+
+In 'pdf' mode, convert the image to PDF using another program.
+
+In orientation check mode, report the orientation is upright.
+"""
+
+import sys
+from pathlib import Path
+
+import img2pdf
+import pikepdf
+from PIL import Image
+
+from ocrmypdf import OcrEngine, OrientationConfidence, hookimpl
+
+HOCR_TEMPLATE = '''<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
+    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
+ <head>
+  <title></title>
+  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+  <meta name='ocr-system' content='tesseract 4.0.0' />
+  <meta name='ocr-capabilities' content='ocr_page ocr_carea ocr_par ocr_line ocrx_word'/>
+ </head>
+ <body>
+  <div class='ocr_page' id='page_1' title='image "x.tif"; bbox 0 0 {0} {1}; ppageno 0'>
+   <div class='ocr_carea' id='block_1_1' title="bbox 0 1 {0} {1}">
+    <p class='ocr_par' dir='ltr' id='par_1' title="bbox 0 1 {0} {1}">
+     <span class='ocr_line' id='line_1' title="bbox 0 1 {0} {1}"><span class='ocrx_word' id='word_1' title="bbox 0 1 {0} {1}"> </span>
+     </span>
+    </p>
+   </div>
+  </div>
+ </body>
+</html>'''
+
+
+class NoopOcrEngine(OcrEngine):
+    @staticmethod
+    def version():
+        return '4.0.0'
+
+    @staticmethod
+    def creator_tag(options):
+        tag = '-PDF' if options.pdf_renderer == 'sandwich' else ''
+        return f"NO-OP {tag} {NoopOcrEngine.version()}"
+
+    def __str__(self):
+        return f"NO-OP {NoopOcrEngine.version()}"
+
+    @staticmethod
+    def languages(options):
+        return {'eng'}
+
+    @staticmethod
+    def get_orientation(input_file, options):
+        return OrientationConfidence(angle=0, confidence=0.0)
+
+    @staticmethod
+    def generate_hocr(input_file, output_hocr, output_text, options):
+        with Image.open(input_file) as im, open(
+            output_hocr, 'w', encoding='utf-8'
+        ) as f:
+            w, h = im.size
+            f.write(HOCR_TEMPLATE.format(str(w), str(h)))
+        with open(output_text, 'w') as f:
+            f.write('')
+
+    @staticmethod
+    def generate_pdf(input_file, output_pdf, output_text, options):
+        with Image.open(input_file) as im:
+            dpi = im.info['dpi']
+            pagesize = im.size[0] / dpi[0], im.size[1] / dpi[1]
+        ptsize = pagesize[0] * 72, pagesize[1] * 72
+        pdf = pikepdf.new()
+        pdf.add_blank_page(page_size=ptsize)
+        pdf.save(output_pdf, static_id=True)
+        output_text.write_text('')
+
+
+@hookimpl
+def get_ocr_engine():
+    return NoopOcrEngine()
@@ -182,14 +182,10 @@ def test_maximum_options(
    )


-def test_tesseract_missing_tessdata(resources, no_outpdf, tmpdir):
-    env = os.environ.copy()
-    env['TESSDATA_PREFIX'] = os.fspath(tmpdir)
-
+def test_tesseract_missing_tessdata(monkeypatch, resources, no_outpdf, tmpdir):
+    monkeypatch.setenv("TESSDATA_PREFIX", os.fspath(tmpdir))
    with pytest.raises(MissingDependencyError):
-        run_ocrmypdf_api(
-            resources / 'graph.pdf', no_outpdf, '-v', '1', '--skip-text', env=env
-        )
+        run_ocrmypdf_api(resources / 'graph.pdf', no_outpdf, '-v', '1', '--skip-text')


 def test_invalid_input_pdf(resources, no_outpdf):