libtiff5

Multipage-tiff fix on resize

Dockerfile

@@ -19,6 +19,7 @@ RUN usermod -d /home www-data \
         libfreetype6-dev \
         libjpeg-dev \
         libpng12-dev \
+        libtiff5-dev \
         libxml2-dev \
         libxslt1-dev \
         zlib1g-dev \

mfr/extensions/pdf/export.py

@@ -1,8 +1,8 @@
 import os
 import imghdr
 from http import HTTPStatus
-
-from PIL import Image
+from PIL import (Image,
+                 TiffImagePlugin)
 from reportlab.pdfgen import canvas
 
 from mfr.core import extension
@@ -18,7 +18,6 @@ def __init__(self, *args, **kwargs):
         self.metrics.add('pil_version', Image.VERSION)
 
     def tiff_to_pdf(self, tiff_img, max_size):
-        width, height = tiff_img.size
         c = canvas.Canvas(self.output_file_path)
         c.setPageSize((max_size[0], max_size[1]))
 
@@ -31,8 +30,28 @@ def tiff_to_pdf(self, tiff_img, max_size):
             except EOFError:
                 break
 
+            # set the width on each iteration in case its different per page
+            width, height = tiff_img.size
+
+            # Use temp_image so we can resize without worry
+            temp_image = tiff_img
             # Center the image and draw it in the canvas
-            c.drawInlineImage(tiff_img, (max_size[0] - width) // 2,
+            if max_size:
+                # Resize the image to the w/h maximum specified
+                ratio = min(max_size[0] / temp_image.size[0], max_size[1] / temp_image.size[1])
+                self.metrics.add('ratio', ratio)
+                if ratio < 1:
+                    temp_image = tiff_img.copy()
+
+                    # Resampling can cause corruption in the image, causing pdf.js to not be able to read it
+                    # Image.ANITALIAS and IMAGE.LANCZOS both caused the error
+                    # Image.BICUBIC was chosen as the highest quality one that did not produce the error
+                    temp_image = temp_image.resize((round(temp_image.size[0] * ratio),
+                                                    round(temp_image.size[1] * ratio)), Image.BICUBIC)
+
+                    width, height = temp_image.size
+
+            c.drawInlineImage(temp_image, (max_size[0] - width) // 2,
                              (max_size[1] - height) // 2, anchor='c')
             c.showPage()
             page += 1
@@ -50,14 +69,9 @@ def export(self):
             'max_size_h': max_size[1],
         })
         try:
+            TiffImagePlugin.READ_LIBTIFF = True
             image = Image.open(self.source_file_path)
-            if max_size:
-                # Resize the image to the w/h maximum specified
-                ratio = min(max_size[0] / image.size[0], max_size[1] / image.size[1])
-                self.metrics.add('ratio', ratio)
-                if ratio < 1:
-                    image = image.resize((round(image.size[0] * ratio),
-                            round(image.size[1] * ratio)), Image.ANTIALIAS)
+
             self.tiff_to_pdf(image, max_size)
             image.close()
 

requirements.txt

@@ -21,7 +21,8 @@ Pygments==2.0.2
 pydocx==0.7.0
 
 # Image
-Pillow==2.8.2
+olefile==0.44
+Pillow==4.3.0 
 psd-tools==1.4
 
 # IPython

tests/extensions/pdf/test_exporter.py

@@ -54,19 +54,6 @@ def test_single_page_tiff(self, directory, file_name):
             # the first 4 bytes contain the signature
             assert binascii.hexlify(file.read(4)) == PDF_SIG
 
-    def test_broken_tiff(self, directory):
-        # Once Pillow is updated to 4.3, this test will fail and can be removed
-        source_file_path = os.path.join(BASE, 'files', 'test_broken.tif')
-        output_file_path = os.path.join(directory, 'test.{}'.format(settings.EXPORT_TYPE))
-        format = '{}.{}'.format(settings.EXPORT_MAXIMUM_SIZE, settings.EXPORT_TYPE)
-        exporter = PdfExporter(source_file_path=source_file_path, ext='.tif',
-                               output_file_path=output_file_path, format=format)
-
-        assert not os.path.exists(output_file_path)
-
-        with pytest.raises(exceptions.PillowImageError):
-            exporter.export()
-
     def test_bad_tiff(self, directory):
         source_file_path = os.path.join(BASE, 'files', 'invalid.tif')
         output_file_path = os.path.join(directory, 'test.{}'.format(settings.EXPORT_TYPE))