ghostscript: remove unnecessary post-render resizing step

2019-05-11 12:10:50 -07:00
parent 0cd576e701
commit bcdd196699
2 changed files with 83 additions and 18 deletions
@@ -0,0 +1,81 @@
+# © 2019 James R. Barlow: github.com/jbarlow83
+#
+# This file is part of OCRmyPDF.
+#
+# OCRmyPDF is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# OCRmyPDF is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
+
+import logging
+from decimal import Decimal
+
+import pikepdf
+import pytest
+from PIL import Image
+
+from ocrmypdf.exec.ghostscript import rasterize_pdf
+
+
+@pytest.fixture
+def linn(resources):
+    path = resources / 'linn.pdf'
+    return path, pikepdf.open(path)
+
+
+def test_rasterize_size(linn, outdir, caplog):
+    path, pdf = linn
+    page_size_pts = (pdf.pages[0].MediaBox[2], pdf.pages[0].MediaBox[3])
+    assert pdf.pages[0].MediaBox[0] == pdf.pages[0].MediaBox[1] == 0
+    page_size = (page_size_pts[0] / Decimal(72), page_size_pts[1] / Decimal(72))
+    target_size = Decimal('200.0'), Decimal('150.0')
+    target_dpi = 42.0, 4242.0
+
+    log = logging.getLogger()
+    rasterize_pdf(
+        path,
+        outdir / 'out.png',
+        target_size[0] / page_size[0],
+        target_size[1] / page_size[1],
+        raster_device='pngmono',
+        log=log,
+        page_dpi=target_dpi,
+    )
+
+    with Image.open(outdir / 'out.png') as im:
+        assert im.size == target_size
+        assert im.info['dpi'] == target_dpi
+
+
+def test_rasterize_rotated(linn, outdir, caplog):
+    path, pdf = linn
+    page_size_pts = (pdf.pages[0].MediaBox[2], pdf.pages[0].MediaBox[3])
+    assert pdf.pages[0].MediaBox[0] == pdf.pages[0].MediaBox[1] == 0
+    page_size = (page_size_pts[0] / Decimal(72), page_size_pts[1] / Decimal(72))
+    target_size = Decimal('200.0'), Decimal('150.0')
+    target_dpi = 42.0, 4242.0
+
+    log = logging.getLogger()
+    caplog.set_level(logging.DEBUG)
+    rasterize_pdf(
+        path,
+        outdir / 'out.png',
+        target_size[0] / page_size[0],
+        target_size[1] / page_size[1],
+        raster_device='pngmono',
+        log=log,
+        page_dpi=target_dpi,
+        rotation=90,
+    )
+
+    with Image.open(outdir / 'out.png') as im:
+        assert im.size == (target_size[1], target_size[0])
+        assert im.info['dpi'] == (target_dpi[1], target_dpi[0])