Pillow/Tests/test_file_tiff_metadata.py
2015-09-13 15:15:13 +01:00

144 lines
5.4 KiB
Python

from __future__ import division
from helper import unittest, PillowTestCase, hopper
from PIL import Image, TiffImagePlugin, TiffTags
tag_ids = dict((info.name, info.value) for info in TiffTags.TAGS_V2.values())
class TestFileTiffMetadata(PillowTestCase):
def test_rt_metadata(self):
""" Test writing arbitrary metadata into the tiff image directory
Use case is ImageJ private tags, one numeric, one arbitrary
data. https://github.com/python-pillow/Pillow/issues/291
"""
img = hopper()
# Behaviour change: re #1416
# Pre ifd rewrite, ImageJMetaData was being written as a string(2),
# Post ifd rewrite, it's defined as arbitrary bytes(7). It should
# roundtrip with the actual bytes, rather than stripped text
# of the premerge tests.
#
# For text items, we still have to decode('ascii','replace') because
# the tiff file format can't take 8 bit bytes in that field.
basetextdata = "This is some arbitrary metadata for a text field"
bindata = basetextdata.encode('ascii') + b" \xff"
textdata = basetextdata + " " + chr(255)
reloaded_textdata = basetextdata + " ?"
floatdata = 12.345
doubledata = 67.89
info = TiffImagePlugin.ImageFileDirectory()
ImageJMetaData = tag_ids['ImageJMetaData']
ImageJMetaDataByteCounts = tag_ids['ImageJMetaDataByteCounts']
ImageDescription = tag_ids['ImageDescription']
info[ImageJMetaDataByteCounts] = len(bindata)
info[ImageJMetaData] = bindata
info[tag_ids['RollAngle']] = floatdata
info.tagtype[tag_ids['RollAngle']] = 11
info[tag_ids['YawAngle']] = doubledata
info.tagtype[tag_ids['YawAngle']] = 12
info[ImageDescription] = textdata
f = self.tempfile("temp.tif")
img.save(f, tiffinfo=info)
loaded = Image.open(f)
self.assertEqual(loaded.tag[ImageJMetaDataByteCounts], (len(bindata),))
self.assertEqual(loaded.tag_v2[ImageJMetaDataByteCounts], len(bindata))
self.assertEqual(loaded.tag[ImageJMetaData], bindata)
self.assertEqual(loaded.tag_v2[ImageJMetaData], bindata)
self.assertEqual(loaded.tag[ImageDescription], (reloaded_textdata,))
self.assertEqual(loaded.tag_v2[ImageDescription], reloaded_textdata)
loaded_float = loaded.tag[tag_ids['RollAngle']][0]
self.assertAlmostEqual(loaded_float, floatdata, places=5)
loaded_double = loaded.tag[tag_ids['YawAngle']][0]
self.assertAlmostEqual(loaded_double, doubledata)
def test_read_metadata(self):
img = Image.open('Tests/images/hopper_g4.tif')
self.assertEqual({'YResolution': 4294967295 / 113653537,
'PlanarConfiguration': 1,
'BitsPerSample': (1,),
'ImageLength': 128,
'Compression': 4,
'FillOrder': 1,
'RowsPerStrip': 128,
'ResolutionUnit': 3,
'PhotometricInterpretation': 0,
'PageNumber': (0, 1),
'XResolution': 4294967295 / 113653537,
'ImageWidth': 128,
'Orientation': 1,
'StripByteCounts': (1968,),
'SamplesPerPixel': 1,
'StripOffsets': (8,)
}, img.tag_v2.named())
self.assertEqual({'YResolution': ((4294967295, 113653537),),
'PlanarConfiguration': (1,),
'BitsPerSample': (1,),
'ImageLength': (128,),
'Compression': (4,),
'FillOrder': (1,),
'RowsPerStrip': (128,),
'ResolutionUnit': (3,),
'PhotometricInterpretation': (0,),
'PageNumber': (0, 1),
'XResolution': ((4294967295, 113653537),),
'ImageWidth': (128,),
'Orientation': (1,),
'StripByteCounts': (1968,),
'SamplesPerPixel': (1,),
'StripOffsets': (8,)
}, img.tag.named())
def test_write_metadata(self):
""" Test metadata writing through the python code """
img = Image.open('Tests/images/hopper.tif')
f = self.tempfile('temp.tiff')
img.save(f, tiffinfo=img.tag)
loaded = Image.open(f)
original = img.tag_v2.named()
reloaded = loaded.tag_v2.named()
ignored = [
'StripByteCounts', 'RowsPerStrip', 'PageNumber', 'StripOffsets']
for tag, value in reloaded.items():
if tag not in ignored:
self.assertEqual(
original[tag], value, "%s didn't roundtrip" % tag)
for tag, value in original.items():
if tag not in ignored:
self.assertEqual(
value, reloaded[tag], "%s didn't roundtrip" % tag)
def test_no_duplicate_50741_tag(self):
self.assertEqual(tag_ids['MakerNoteSafety'], 50741)
self.assertEqual(tag_ids['BestQualityScale'], 50780)
if __name__ == '__main__':
unittest.main()
# End of file