Fix issue #147: unpaper loses DPI information, affects —pdf-renderer …

…tess4

RELEASE_NOTES.rst

@@ -4,6 +4,14 @@ RELEASE NOTES
 OCRmyPDF uses `semantic versioning <http://semver.org/>`_.
 
 
+v4.5.2
+======
+
+-  Fix issue #147, unpaper loses DPI information, which affects PDF rendering with ``--pdf-renderer tess4``
+-  Make "using Tesseract 4.0" warning less ominous
+-  Set up machinery for homebrew OCRmyPDF tap
+
+
 v4.5.1
 ======
 

ocrmypdf/exec/unpaper.py

@@ -78,7 +78,8 @@ def run(input_file, output_file, dpi, log, mode_args):
             raise e from e
         else:
             log.debug(stdout)
-            Image.open(output_pnm.name).save(output_file)
+            # unpaper sets dpi to 72
+            Image.open(output_pnm.name).save(output_file, dpi=(dpi, dpi))
 
 
 def deskew(input_file, output_file, dpi, log):

tests/conftest.py

@@ -101,7 +101,7 @@ def check_ocrmypdf(input_file, output_file, *args, env=None):
 
     p, out, err = run_ocrmypdf(input_file, output_file, *args, env=env)
     #print(err)  # ensure py.test collects the output, use -s to view
-    assert p.returncode == 0
+    assert p.returncode == 0, "<stderr>\n" + err + "\n</stderr>"
     assert os.path.exists(str(output_file)), "Output file not created"
     assert os.stat(str(output_file)).st_size > 100, "PDF too small or empty"
     assert out == "", \
@@ -125,3 +125,11 @@ def run_ocrmypdf(input_file, output_file, *args, env=None):
     #print(err)
 
     return p, out, err
+
+
+@pytest.helpers.register
+def first_page_dimensions(pdf):
+    from ocrmypdf import pageinfo
+    info = pageinfo.pdf_get_all_pageinfo(str(pdf))
+    page0 = info[0]
+    return (page0['width_inches'], page0['height_inches'])

tests/test_main.py

@@ -812,3 +812,28 @@ def test_form_xobject(spoof_tesseract_noop, resources, outpdf):
     check_ocrmypdf(resources / 'formxobject.pdf', outpdf,
                    '--force-ocr',
                    env=spoof_tesseract_noop)
+
+
+@pytest.mark.skipif(sys.version_info < (3, 5), reason="needs math.isclose")
+@pytest.mark.parametrize('renderer', [
+    'hocr',
+    'tesseract',
+])
+def test_pagesize_consistency(renderer, resources, outpdf):
+    from math import isclose
+
+    first_page_dimensions = pytest.helpers.first_page_dimensions
+
+    infile = resources / 'linn.pdf'
+
+    before_dims = first_page_dimensions(infile)
+
+    check_ocrmypdf(
+        infile,
+        outpdf, '--pdf-renderer', renderer,
+        '--clean', '--deskew', '--remove-background', '--clean-final')
+
+    after_dims = first_page_dimensions(outpdf)
+
+    assert isclose(before_dims[0], after_dims[0])
+    assert isclose(before_dims[1], after_dims[1])

tests/test_tess4.py

@@ -4,19 +4,40 @@
 import pytest
 from ocrmypdf.exceptions import ExitCode
 from ocrmypdf.exec import tesseract
+from ocrmypdf import pageinfo
+import sys
 
 
 # Skip all tests in this file if not tesseract 4
-pytestmark = pytest.mark.skipif(not tesseract.v4(),
-                                reason="tesseract 4.0 required")
+pytestmark = pytest.mark.skipif(
+    not (tesseract.v4() and tesseract.has_textonly_pdf()),
+    reason="tesseract 4.0 with textonly_pdf feature required")
+
+check_ocrmypdf = pytest.helpers.check_ocrmypdf
+run_ocrmypdf = pytest.helpers.run_ocrmypdf
+spoof = pytest.helpers.spoof
 
 
-@pytest.mark.skipif(not tesseract.has_textonly_pdf(),
-                    reason="requires textonly_pdf feature")
 def test_textonly_pdf(resources, outdir):
-    pytest.helpers.check_ocrmypdf(
+    check_ocrmypdf(
         resources / 'linn.pdf',
         outdir / 'linn_textonly.pdf', '--pdf-renderer', 'tess4')
 
 
+@pytest.mark.skipif(sys.version_info < (3, 5), reason="needs math.isclose")
+def test_pagesize_consistency_tess4(resources, outpdf):
+    from math import isclose
+
+    infile = resources / 'linn.pdf'
+
+    before_dims = pytest.helpers.first_page_dimensions(infile)
+
+    check_ocrmypdf(
+        infile,
+        outpdf, '--pdf-renderer', 'tess4',
+        '--clean', '--deskew', '--remove-background', '--clean-final')
+
+    after_dims = pytest.helpers.first_page_dimensions(outpdf)
 
+    assert isclose(before_dims[0], after_dims[0])
+    assert isclose(before_dims[1], after_dims[1])