Merge pull request #4626 from radarhere/stripbytecounts

Change STRIPBYTECOUNTS to LONG if necessary when saving
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Andrew Murray 2020-06-21 09:02:56 +10:00 committed by GitHub
commit 8383e840e4
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2 changed files with 21 additions and 1 deletions

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@ -156,6 +156,23 @@ def test_write_metadata(tmp_path):
assert value == reloaded[tag], "%s didn't roundtrip" % tag assert value == reloaded[tag], "%s didn't roundtrip" % tag
def test_change_stripbytecounts_tag_type(tmp_path):
out = str(tmp_path / "temp.tiff")
with Image.open("Tests/images/hopper.tif") as im:
info = im.tag_v2
# Resize the image so that STRIPBYTECOUNTS will be larger than a SHORT
im = im.resize((500, 500))
# STRIPBYTECOUNTS can be a SHORT or a LONG
info.tagtype[TiffImagePlugin.STRIPBYTECOUNTS] = TiffTags.SHORT
im.save(out, tiffinfo=info)
with Image.open(out) as reloaded:
assert reloaded.tag_v2.tagtype[TiffImagePlugin.STRIPBYTECOUNTS] == TiffTags.LONG
def test_no_duplicate_50741_tag(): def test_no_duplicate_50741_tag():
assert TAG_IDS["MakerNoteSafety"] == 50741 assert TAG_IDS["MakerNoteSafety"] == 50741
assert TAG_IDS["BestQualityScale"] == 50780 assert TAG_IDS["BestQualityScale"] == 50780

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@ -1491,7 +1491,10 @@ def _save(im, fp, filename):
# data orientation # data orientation
stride = len(bits) * ((im.size[0] * bits[0] + 7) // 8) stride = len(bits) * ((im.size[0] * bits[0] + 7) // 8)
ifd[ROWSPERSTRIP] = im.size[1] ifd[ROWSPERSTRIP] = im.size[1]
ifd[STRIPBYTECOUNTS] = stride * im.size[1] strip_byte_counts = stride * im.size[1]
if strip_byte_counts >= 2 ** 16:
ifd.tagtype[STRIPBYTECOUNTS] = TiffTags.LONG
ifd[STRIPBYTECOUNTS] = strip_byte_counts
ifd[STRIPOFFSETS] = 0 # this is adjusted by IFD writer ifd[STRIPOFFSETS] = 0 # this is adjusted by IFD writer
# no compression by default: # no compression by default:
ifd[COMPRESSION] = COMPRESSION_INFO_REV.get(compression, 1) ifd[COMPRESSION] = COMPRESSION_INFO_REV.get(compression, 1)