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Merge pull request #7650 from radarhere/tiff

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Allow uncompressed TIFF images to be saved in chunks
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Andrew Murray 2024-01-01 14:27:10 +11:00 committed by GitHub
commit bd7e709141
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3 changed files with 31 additions and 10 deletions
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25
Tests/test_file_tiff.py
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@ -484,13 +484,13 @@ class TestFileTiff:
outfile = str(tmp_path / "temp.tif")
with Image.open("Tests/images/ifd_tag_type.tiff") as im:
exif = im.getexif()
exif[256] = 100
exif[264] = 100
im.save(outfile, exif=exif)
with Image.open(outfile) as im:
exif = im.getexif()
assert exif[256] == 100
assert exif[264] == 100
def test_reload_exif_after_seek(self):
with Image.open("Tests/images/multipage.tiff") as im:
@ -781,6 +781,27 @@ class TestFileTiff:
4001,
]
def test_tiff_chunks(self, tmp_path):
tmpfile = str(tmp_path / "temp.tif")
im = hopper()
with open(tmpfile, "wb") as fp:
for y in range(0, 128, 32):
chunk = im.crop((0, y, 128, y + 32))
if y == 0:
chunk.save(
fp,
"TIFF",
tiffinfo={
TiffImagePlugin.IMAGEWIDTH: 128,
TiffImagePlugin.IMAGELENGTH: 128,
},
)
else:
fp.write(chunk.tobytes())
assert_image_equal_tofile(im, tmpfile)
def test_close_on_load_exclusive(self, tmp_path):
# similar to test_fd_leak, but runs on unixlike os
tmpfile = str(tmp_path / "temp.tif")

1
Tests/test_file_tiff_metadata.py
View File

@ -164,6 +164,7 @@ def test_change_stripbytecounts_tag_type(tmp_path):
# Resize the image so that STRIPBYTECOUNTS will be larger than a SHORT
im = im.resize((500, 500))
info[TiffImagePlugin.IMAGEWIDTH] = im.width
# STRIPBYTECOUNTS can be a SHORT or a LONG
info.tagtype[TiffImagePlugin.STRIPBYTECOUNTS] = TiffTags.SHORT

15
src/PIL/TiffImagePlugin.py
View File

@ -1704,28 +1704,27 @@ def _save(im, fp, filename):
colormap += [0] * (256 - colors)
ifd[COLORMAP] = colormap
# data orientation
stride = len(bits) * ((im.size[0] * bits[0] + 7) // 8)
w, h = ifd[IMAGEWIDTH], ifd[IMAGELENGTH]
stride = len(bits) * ((w * bits[0] + 7) // 8)
if ROWSPERSTRIP not in ifd:
# aim for given strip size (64 KB by default) when using libtiff writer
if libtiff:
im_strip_size = encoderinfo.get("strip_size", STRIP_SIZE)
rows_per_strip = (
1 if stride == 0 else min(im_strip_size // stride, im.size[1])
)
rows_per_strip = 1 if stride == 0 else min(im_strip_size // stride, h)
# JPEG encoder expects multiple of 8 rows
if compression == "jpeg":
rows_per_strip = min(((rows_per_strip + 7) // 8) * 8, im.size[1])
rows_per_strip = min(((rows_per_strip + 7) // 8) * 8, h)
else:
rows_per_strip = im.size[1]
rows_per_strip = h
if rows_per_strip == 0:
rows_per_strip = 1
ifd[ROWSPERSTRIP] = rows_per_strip
strip_byte_counts = 1 if stride == 0 else stride * ifd[ROWSPERSTRIP]
strips_per_image = (im.size[1] + ifd[ROWSPERSTRIP] - 1) // ifd[ROWSPERSTRIP]
strips_per_image = (h + ifd[ROWSPERSTRIP] - 1) // ifd[ROWSPERSTRIP]
if strip_byte_counts >= 2**16:
ifd.tagtype[STRIPBYTECOUNTS] = TiffTags.LONG
ifd[STRIPBYTECOUNTS] = (strip_byte_counts,) * (strips_per_image - 1) + (
stride * im.size[1] - strip_byte_counts * (strips_per_image - 1),
stride * h - strip_byte_counts * (strips_per_image - 1),
)
ifd[STRIPOFFSETS] = tuple(
range(0, strip_byte_counts * strips_per_image, strip_byte_counts)