From 9e5650914c1662981c116145de68b2fb9b56e0ae Mon Sep 17 00:00:00 2001
From: nathanf <nathanf@zillow.com>
Date: Mon, 15 Aug 2016 17:49:16 -0700
Subject: [PATCH] Store TIFF DPI as integer

---
 PIL/TiffImagePlugin.py  |  5 +++--
 Tests/test_file_tiff.py | 14 ++++++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/PIL/TiffImagePlugin.py b/PIL/TiffImagePlugin.py
index 524d42a34..304b027d5 100644
--- a/PIL/TiffImagePlugin.py
+++ b/PIL/TiffImagePlugin.py
@@ -52,6 +52,7 @@ from numbers import Number, Rational
 
 import io
 import itertools
+import math
 import os
 import struct
 import sys
@@ -1154,9 +1155,9 @@ class TiffImageFile(ImageFile.ImageFile):
         if xres and yres:
             resunit = self.tag_v2.get(RESOLUTION_UNIT, 1)
             if resunit == 2:  # dots per inch
-                self.info["dpi"] = xres, yres
+                self.info["dpi"] = int(math.ceil(xres)), int(math.ceil(yres))
             elif resunit == 3:  # dots per centimeter. convert to dpi
-                self.info["dpi"] = xres * 2.54, yres * 2.54
+                self.info["dpi"] = int(math.ceil(xres * 2.54)), int(math.ceil(yres * 2.54))
             else:  # No absolute unit of measurement
                 self.info["resolution"] = xres, yres
 
diff --git a/Tests/test_file_tiff.py b/Tests/test_file_tiff.py
index 5b01de12b..14c5d398c 100644
--- a/Tests/test_file_tiff.py
+++ b/Tests/test_file_tiff.py
@@ -470,6 +470,20 @@ class TestFileTiff(PillowTestCase):
         im = Image.open(infile)
         self.assertEqual(im.getpixel((0, 0)), pixel_value)
 
+    def test_save_tiff_with_dpi(self):
+
+        outfile = self.tempfile("temp.tif")
+
+        infile = "Tests/images/hopper.tif"
+        im = Image.open(infile)
+
+        im.save(outfile, 'JPEG', dpi=im.info['dpi'])
+
+        reloaded = Image.open(outfile)
+        reloaded.load()
+
+        self.assertEqual(im.info['dpi'], reloaded.info['dpi'])
+
 
 if __name__ == '__main__':
     unittest.main()