import os import re from io import BytesIO import pytest from PIL import ( ExifTags, Image, ImageFile, ImageOps, JpegImagePlugin, UnidentifiedImageError, features, ) from .helper import ( assert_image, assert_image_equal, assert_image_similar, cjpeg_available, djpeg_available, hopper, is_win32, skip_unless_feature, ) TEST_FILE = "Tests/images/hopper.jpg" @skip_unless_feature("jpg") class TestFileJpeg: def roundtrip(self, im, **options): out = BytesIO() im.save(out, "JPEG", **options) test_bytes = out.tell() out.seek(0) im = Image.open(out) im.bytes = test_bytes # for testing only return im def gen_random_image(self, size, mode="RGB"): """Generates a very hard to compress file :param size: tuple :param mode: optional image mode """ return Image.frombytes(mode, size, os.urandom(size[0] * size[1] * len(mode))) def test_sanity(self): # internal version number assert re.search(r"\d+\.\d+$", features.version_codec("jpg")) with Image.open(TEST_FILE) as im: im.load() assert im.mode == "RGB" assert im.size == (128, 128) assert im.format == "JPEG" assert im.get_format_mimetype() == "image/jpeg" def test_app(self): # Test APP/COM reader (@PIL135) with Image.open(TEST_FILE) as im: assert im.applist[0] == ("APP0", b"JFIF\x00\x01\x01\x01\x00`\x00`\x00\x00") assert im.applist[1] == ( "COM", b"File written by Adobe Photoshop\xa8 4.0\x00", ) assert len(im.applist) == 2 assert im.info["comment"] == b"File written by Adobe Photoshop\xa8 4.0\x00" def test_cmyk(self): # Test CMYK handling. Thanks to Tim and Charlie for test data, # Michael for getting me to look one more time. f = "Tests/images/pil_sample_cmyk.jpg" with Image.open(f) as im: # the source image has red pixels in the upper left corner. c, m, y, k = [x / 255.0 for x in im.getpixel((0, 0))] assert c == 0.0 assert m > 0.8 assert y > 0.8 assert k == 0.0 # the opposite corner is black c, m, y, k = [ x / 255.0 for x in im.getpixel((im.size[0] - 1, im.size[1] - 1)) ] assert k > 0.9 # roundtrip, and check again im = self.roundtrip(im) c, m, y, k = [x / 255.0 for x in im.getpixel((0, 0))] assert c == 0.0 assert m > 0.8 assert y > 0.8 assert k == 0.0 c, m, y, k = [ x / 255.0 for x in im.getpixel((im.size[0] - 1, im.size[1] - 1)) ] assert k > 0.9 @pytest.mark.parametrize( "test_image_path", [TEST_FILE, "Tests/images/pil_sample_cmyk.jpg"], ) def test_dpi(self, test_image_path): def test(xdpi, ydpi=None): with Image.open(test_image_path) as im: im = self.roundtrip(im, dpi=(xdpi, ydpi or xdpi)) return im.info.get("dpi") assert test(72) == (72, 72) assert test(300) == (300, 300) assert test(100, 200) == (100, 200) assert test(0) is None # square pixels def test_icc(self, tmp_path): # Test ICC support with Image.open("Tests/images/rgb.jpg") as im1: icc_profile = im1.info["icc_profile"] assert len(icc_profile) == 3144 # Roundtrip via physical file. f = str(tmp_path / "temp.jpg") im1.save(f, icc_profile=icc_profile) with Image.open(f) as im2: assert im2.info.get("icc_profile") == icc_profile # Roundtrip via memory buffer. im1 = self.roundtrip(hopper()) im2 = self.roundtrip(hopper(), icc_profile=icc_profile) assert_image_equal(im1, im2) assert not im1.info.get("icc_profile") assert im2.info.get("icc_profile") def test_icc_big(self): # Make sure that the "extra" support handles large blocks def test(n): # The ICC APP marker can store 65519 bytes per marker, so # using a 4-byte test code should allow us to detect out of # order issues. icc_profile = (b"Test" * int(n / 4 + 1))[:n] assert len(icc_profile) == n # sanity im1 = self.roundtrip(hopper(), icc_profile=icc_profile) assert im1.info.get("icc_profile") == (icc_profile or None) test(0) test(1) test(3) test(4) test(5) test(65533 - 14) # full JPEG marker block test(65533 - 14 + 1) # full block plus one byte test(ImageFile.MAXBLOCK) # full buffer block test(ImageFile.MAXBLOCK + 1) # full buffer block plus one byte test(ImageFile.MAXBLOCK * 4 + 3) # large block def test_large_icc_meta(self, tmp_path): # https://github.com/python-pillow/Pillow/issues/148 # Sometimes the meta data on the icc_profile block is bigger than # Image.MAXBLOCK or the image size. with Image.open("Tests/images/icc_profile_big.jpg") as im: f = str(tmp_path / "temp.jpg") icc_profile = im.info["icc_profile"] # Should not raise OSError for image with icc larger than image size. im.save( f, format="JPEG", progressive=True, quality=95, icc_profile=icc_profile, optimize=True, ) def test_optimize(self): im1 = self.roundtrip(hopper()) im2 = self.roundtrip(hopper(), optimize=0) im3 = self.roundtrip(hopper(), optimize=1) assert_image_equal(im1, im2) assert_image_equal(im1, im3) assert im1.bytes >= im2.bytes assert im1.bytes >= im3.bytes def test_optimize_large_buffer(self, tmp_path): # https://github.com/python-pillow/Pillow/issues/148 f = str(tmp_path / "temp.jpg") # this requires ~ 1.5x Image.MAXBLOCK im = Image.new("RGB", (4096, 4096), 0xFF3333) im.save(f, format="JPEG", optimize=True) def test_progressive(self): im1 = self.roundtrip(hopper()) im2 = self.roundtrip(hopper(), progressive=False) im3 = self.roundtrip(hopper(), progressive=True) assert not im1.info.get("progressive") assert not im2.info.get("progressive") assert im3.info.get("progressive") assert_image_equal(im1, im3) assert im1.bytes >= im3.bytes def test_progressive_large_buffer(self, tmp_path): f = str(tmp_path / "temp.jpg") # this requires ~ 1.5x Image.MAXBLOCK im = Image.new("RGB", (4096, 4096), 0xFF3333) im.save(f, format="JPEG", progressive=True) def test_progressive_large_buffer_highest_quality(self, tmp_path): f = str(tmp_path / "temp.jpg") im = self.gen_random_image((255, 255)) # this requires more bytes than pixels in the image im.save(f, format="JPEG", progressive=True, quality=100) def test_progressive_cmyk_buffer(self): # Issue 2272, quality 90 cmyk image is tripping the large buffer bug. f = BytesIO() im = self.gen_random_image((256, 256), "CMYK") im.save(f, format="JPEG", progressive=True, quality=94) def test_large_exif(self, tmp_path): # https://github.com/python-pillow/Pillow/issues/148 f = str(tmp_path / "temp.jpg") im = hopper() im.save(f, "JPEG", quality=90, exif=b"1" * 65532) def test_exif_typeerror(self): with Image.open("Tests/images/exif_typeerror.jpg") as im: # Should not raise a TypeError im._getexif() def test_exif_gps(self, tmp_path): expected_exif_gps = { 0: b"\x00\x00\x00\x01", 2: 4294967295, 5: b"\x01", 30: 65535, 29: "1999:99:99 99:99:99", } gps_index = 34853 # Reading with Image.open("Tests/images/exif_gps.jpg") as im: exif = im._getexif() assert exif[gps_index] == expected_exif_gps # Writing f = str(tmp_path / "temp.jpg") exif = Image.Exif() exif[gps_index] = expected_exif_gps hopper().save(f, exif=exif) with Image.open(f) as reloaded: exif = reloaded._getexif() assert exif[gps_index] == expected_exif_gps def test_empty_exif_gps(self): with Image.open("Tests/images/empty_gps_ifd.jpg") as im: exif = im.getexif() del exif[0x8769] # Assert that it needs to be transposed assert exif[0x0112] == Image.TRANSVERSE # Assert that the GPS IFD is present and empty assert exif[0x8825] == {} transposed = ImageOps.exif_transpose(im) exif = transposed.getexif() assert exif[0x8825] == {} # Assert that it was transposed assert 0x0112 not in exif def test_exif_equality(self): # In 7.2.0, Exif rationals were changed to be read as # TiffImagePlugin.IFDRational. This class had a bug in __eq__, # breaking the self-equality of Exif data exifs = [] for i in range(2): with Image.open("Tests/images/exif-200dpcm.jpg") as im: exifs.append(im._getexif()) assert exifs[0] == exifs[1] def test_exif_rollback(self): # rolling back exif support in 3.1 to pre-3.0 formatting. # expected from 2.9, with b/u qualifiers switched for 3.2 compatibility # this test passes on 2.9 and 3.1, but not 3.0 expected_exif = { 34867: 4294967295, 258: (24, 24, 24), 36867: "2099:09:29 10:10:10", 34853: { 0: b"\x00\x00\x00\x01", 2: 4294967295, 5: b"\x01", 30: 65535, 29: "1999:99:99 99:99:99", }, 296: 65535, 34665: 185, 41994: 65535, 514: 4294967295, 271: "Make", 272: "XXX-XXX", 305: "PIL", 42034: (1, 1, 1, 1), 42035: "LensMake", 34856: b"\xaa\xaa\xaa\xaa\xaa\xaa", 282: 4294967295, 33434: 4294967295, } with Image.open("Tests/images/exif_gps.jpg") as im: exif = im._getexif() for tag, value in expected_exif.items(): assert value == exif[tag] def test_exif_gps_typeerror(self): with Image.open("Tests/images/exif_gps_typeerror.jpg") as im: # Should not raise a TypeError im._getexif() def test_progressive_compat(self): im1 = self.roundtrip(hopper()) assert not im1.info.get("progressive") assert not im1.info.get("progression") im2 = self.roundtrip(hopper(), progressive=0) im3 = self.roundtrip(hopper(), progression=0) # compatibility assert not im2.info.get("progressive") assert not im2.info.get("progression") assert not im3.info.get("progressive") assert not im3.info.get("progression") im2 = self.roundtrip(hopper(), progressive=1) im3 = self.roundtrip(hopper(), progression=1) # compatibility assert_image_equal(im1, im2) assert_image_equal(im1, im3) assert im2.info.get("progressive") assert im2.info.get("progression") assert im3.info.get("progressive") assert im3.info.get("progression") def test_quality(self): im1 = self.roundtrip(hopper()) im2 = self.roundtrip(hopper(), quality=50) assert_image(im1, im2.mode, im2.size) assert im1.bytes >= im2.bytes im3 = self.roundtrip(hopper(), quality=0) assert_image(im1, im3.mode, im3.size) assert im2.bytes > im3.bytes def test_smooth(self): im1 = self.roundtrip(hopper()) im2 = self.roundtrip(hopper(), smooth=100) assert_image(im1, im2.mode, im2.size) def test_subsampling(self): def getsampling(im): layer = im.layer return layer[0][1:3] + layer[1][1:3] + layer[2][1:3] # experimental API im = self.roundtrip(hopper(), subsampling=-1) # default assert getsampling(im) == (2, 2, 1, 1, 1, 1) im = self.roundtrip(hopper(), subsampling=0) # 4:4:4 assert getsampling(im) == (1, 1, 1, 1, 1, 1) im = self.roundtrip(hopper(), subsampling=1) # 4:2:2 assert getsampling(im) == (2, 1, 1, 1, 1, 1) im = self.roundtrip(hopper(), subsampling=2) # 4:2:0 assert getsampling(im) == (2, 2, 1, 1, 1, 1) im = self.roundtrip(hopper(), subsampling=3) # default (undefined) assert getsampling(im) == (2, 2, 1, 1, 1, 1) im = self.roundtrip(hopper(), subsampling="4:4:4") assert getsampling(im) == (1, 1, 1, 1, 1, 1) im = self.roundtrip(hopper(), subsampling="4:2:2") assert getsampling(im) == (2, 1, 1, 1, 1, 1) im = self.roundtrip(hopper(), subsampling="4:2:0") assert getsampling(im) == (2, 2, 1, 1, 1, 1) im = self.roundtrip(hopper(), subsampling="4:1:1") assert getsampling(im) == (2, 2, 1, 1, 1, 1) with pytest.raises(TypeError): self.roundtrip(hopper(), subsampling="1:1:1") def test_exif(self): with Image.open("Tests/images/pil_sample_rgb.jpg") as im: info = im._getexif() assert info[305] == "Adobe Photoshop CS Macintosh" def test_mp(self): with Image.open("Tests/images/pil_sample_rgb.jpg") as im: assert im._getmp() is None def test_quality_keep(self, tmp_path): # RGB with Image.open("Tests/images/hopper.jpg") as im: f = str(tmp_path / "temp.jpg") im.save(f, quality="keep") # Grayscale with Image.open("Tests/images/hopper_gray.jpg") as im: f = str(tmp_path / "temp.jpg") im.save(f, quality="keep") # CMYK with Image.open("Tests/images/pil_sample_cmyk.jpg") as im: f = str(tmp_path / "temp.jpg") im.save(f, quality="keep") def test_junk_jpeg_header(self): # https://github.com/python-pillow/Pillow/issues/630 filename = "Tests/images/junk_jpeg_header.jpg" with Image.open(filename): pass def test_ff00_jpeg_header(self): filename = "Tests/images/jpeg_ff00_header.jpg" with Image.open(filename): pass def test_truncated_jpeg_should_read_all_the_data(self): filename = "Tests/images/truncated_jpeg.jpg" ImageFile.LOAD_TRUNCATED_IMAGES = True with Image.open(filename) as im: im.load() ImageFile.LOAD_TRUNCATED_IMAGES = False assert im.getbbox() is not None def test_truncated_jpeg_throws_oserror(self): filename = "Tests/images/truncated_jpeg.jpg" with Image.open(filename) as im: with pytest.raises(OSError): im.load() # Test that the error is raised if loaded a second time with pytest.raises(OSError): im.load() def test_qtables(self, tmp_path): def _n_qtables_helper(n, test_file): with Image.open(test_file) as im: f = str(tmp_path / "temp.jpg") im.save(f, qtables=[[n] * 64] * n) with Image.open(f) as im: assert len(im.quantization) == n reloaded = self.roundtrip(im, qtables="keep") assert im.quantization == reloaded.quantization with Image.open("Tests/images/hopper.jpg") as im: qtables = im.quantization reloaded = self.roundtrip(im, qtables=qtables, subsampling=0) assert im.quantization == reloaded.quantization assert_image_similar(im, self.roundtrip(im, qtables="web_low"), 30) assert_image_similar(im, self.roundtrip(im, qtables="web_high"), 30) assert_image_similar(im, self.roundtrip(im, qtables="keep"), 30) # valid bounds for baseline qtable bounds_qtable = [int(s) for s in ("255 1 " * 32).split(None)] self.roundtrip(im, qtables=[bounds_qtable]) # values from wizard.txt in jpeg9-a src package. standard_l_qtable = [ int(s) for s in """ 16 11 10 16 24 40 51 61 12 12 14 19 26 58 60 55 14 13 16 24 40 57 69 56 14 17 22 29 51 87 80 62 18 22 37 56 68 109 103 77 24 35 55 64 81 104 113 92 49 64 78 87 103 121 120 101 72 92 95 98 112 100 103 99 """.split( None ) ] standard_chrominance_qtable = [ int(s) for s in """ 17 18 24 47 99 99 99 99 18 21 26 66 99 99 99 99 24 26 56 99 99 99 99 99 47 66 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 """.split( None ) ] # list of qtable lists assert_image_similar( im, self.roundtrip( im, qtables=[standard_l_qtable, standard_chrominance_qtable] ), 30, ) # tuple of qtable lists assert_image_similar( im, self.roundtrip( im, qtables=(standard_l_qtable, standard_chrominance_qtable) ), 30, ) # dict of qtable lists assert_image_similar( im, self.roundtrip( im, qtables={0: standard_l_qtable, 1: standard_chrominance_qtable} ), 30, ) _n_qtables_helper(1, "Tests/images/hopper_gray.jpg") _n_qtables_helper(1, "Tests/images/pil_sample_rgb.jpg") _n_qtables_helper(2, "Tests/images/pil_sample_rgb.jpg") _n_qtables_helper(3, "Tests/images/pil_sample_rgb.jpg") _n_qtables_helper(1, "Tests/images/pil_sample_cmyk.jpg") _n_qtables_helper(2, "Tests/images/pil_sample_cmyk.jpg") _n_qtables_helper(3, "Tests/images/pil_sample_cmyk.jpg") _n_qtables_helper(4, "Tests/images/pil_sample_cmyk.jpg") # not a sequence with pytest.raises(ValueError): self.roundtrip(im, qtables="a") # sequence wrong length with pytest.raises(ValueError): self.roundtrip(im, qtables=[]) # sequence wrong length with pytest.raises(ValueError): self.roundtrip(im, qtables=[1, 2, 3, 4, 5]) # qtable entry not a sequence with pytest.raises(ValueError): self.roundtrip(im, qtables=[1]) # qtable entry has wrong number of items with pytest.raises(ValueError): self.roundtrip(im, qtables=[[1, 2, 3, 4]]) @pytest.mark.skipif(not djpeg_available(), reason="djpeg not available") def test_load_djpeg(self): with Image.open(TEST_FILE) as img: img.load_djpeg() assert_image_similar(img, Image.open(TEST_FILE), 5) @pytest.mark.skipif(not cjpeg_available(), reason="cjpeg not available") def test_save_cjpeg(self, tmp_path): with Image.open(TEST_FILE) as img: tempfile = str(tmp_path / "temp.jpg") JpegImagePlugin._save_cjpeg(img, 0, tempfile) # Default save quality is 75%, so a tiny bit of difference is alright assert_image_similar(img, Image.open(tempfile), 17) def test_no_duplicate_0x1001_tag(self): # Arrange tag_ids = {v: k for k, v in ExifTags.TAGS.items()} # Assert assert tag_ids["RelatedImageWidth"] == 0x1001 assert tag_ids["RelatedImageLength"] == 0x1002 def test_MAXBLOCK_scaling(self, tmp_path): im = self.gen_random_image((512, 512)) f = str(tmp_path / "temp.jpeg") im.save(f, quality=100, optimize=True) with Image.open(f) as reloaded: # none of these should crash reloaded.save(f, quality="keep") reloaded.save(f, quality="keep", progressive=True) reloaded.save(f, quality="keep", optimize=True) def test_bad_mpo_header(self): """ Treat unknown MPO as JPEG """ # Arrange # Act # Shouldn't raise error fn = "Tests/images/sugarshack_bad_mpo_header.jpg" with pytest.warns(UserWarning, Image.open, fn) as im: # Assert assert im.format == "JPEG" def test_save_correct_modes(self): out = BytesIO() for mode in ["1", "L", "RGB", "RGBX", "CMYK", "YCbCr"]: img = Image.new(mode, (20, 20)) img.save(out, "JPEG") def test_save_wrong_modes(self): # ref https://github.com/python-pillow/Pillow/issues/2005 out = BytesIO() for mode in ["LA", "La", "RGBA", "RGBa", "P"]: img = Image.new(mode, (20, 20)) with pytest.raises(OSError): img.save(out, "JPEG") def test_save_tiff_with_dpi(self, tmp_path): # Arrange outfile = str(tmp_path / "temp.tif") with Image.open("Tests/images/hopper.tif") as im: # Act im.save(outfile, "JPEG", dpi=im.info["dpi"]) # Assert with Image.open(outfile) as reloaded: reloaded.load() assert im.info["dpi"] == reloaded.info["dpi"] def test_load_dpi_rounding(self): # Round up with Image.open("Tests/images/iptc_roundUp.jpg") as im: assert im.info["dpi"] == (44, 44) # Round down with Image.open("Tests/images/iptc_roundDown.jpg") as im: assert im.info["dpi"] == (2, 2) def test_save_dpi_rounding(self, tmp_path): outfile = str(tmp_path / "temp.jpg") with Image.open("Tests/images/hopper.jpg") as im: im.save(outfile, dpi=(72.2, 72.2)) with Image.open(outfile) as reloaded: assert reloaded.info["dpi"] == (72, 72) im.save(outfile, dpi=(72.8, 72.8)) with Image.open(outfile) as reloaded: assert reloaded.info["dpi"] == (73, 73) def test_dpi_tuple_from_exif(self): # Arrange # This Photoshop CC 2017 image has DPI in EXIF not metadata # EXIF XResolution is (2000000, 10000) with Image.open("Tests/images/photoshop-200dpi.jpg") as im: # Act / Assert assert im.info.get("dpi") == (200, 200) def test_dpi_int_from_exif(self): # Arrange # This image has DPI in EXIF not metadata # EXIF XResolution is 72 with Image.open("Tests/images/exif-72dpi-int.jpg") as im: # Act / Assert assert im.info.get("dpi") == (72, 72) def test_dpi_from_dpcm_exif(self): # Arrange # This is photoshop-200dpi.jpg with EXIF resolution unit set to cm: # exiftool -exif:ResolutionUnit=cm photoshop-200dpi.jpg with Image.open("Tests/images/exif-200dpcm.jpg") as im: # Act / Assert assert im.info.get("dpi") == (508, 508) def test_dpi_exif_zero_division(self): # Arrange # This is photoshop-200dpi.jpg with EXIF resolution set to 0/0: # exiftool -XResolution=0/0 -YResolution=0/0 photoshop-200dpi.jpg with Image.open("Tests/images/exif-dpi-zerodivision.jpg") as im: # Act / Assert # This should return the default, and not raise a ZeroDivisionError assert im.info.get("dpi") == (72, 72) def test_no_dpi_in_exif(self): # Arrange # This is photoshop-200dpi.jpg with resolution removed from EXIF: # exiftool "-*resolution*"= photoshop-200dpi.jpg with Image.open("Tests/images/no-dpi-in-exif.jpg") as im: # Act / Assert # "When the image resolution is unknown, 72 [dpi] is designated." # http://www.exiv2.org/tags.html assert im.info.get("dpi") == (72, 72) def test_invalid_exif(self): # This is no-dpi-in-exif with the tiff header of the exif block # hexedited from MM * to FF FF FF FF with Image.open("Tests/images/invalid-exif.jpg") as im: # This should return the default, and not a SyntaxError or # OSError for unidentified image. assert im.info.get("dpi") == (72, 72) def test_exif_x_resolution(self, tmp_path): with Image.open("Tests/images/flower.jpg") as im: exif = im.getexif() assert exif[282] == 180 out = str(tmp_path / "out.jpg") with pytest.warns(None) as record: im.save(out, exif=exif) assert len(record) == 0 with Image.open(out) as reloaded: assert reloaded.getexif()[282] == 180 def test_invalid_exif_x_resolution(self): # When no x or y resolution is defined in EXIF with Image.open("Tests/images/invalid-exif-without-x-resolution.jpg") as im: # This should return the default, and not a ValueError or # OSError for an unidentified image. assert im.info.get("dpi") == (72, 72) def test_ifd_offset_exif(self): # Arrange # This image has been manually hexedited to have an IFD offset of 10, # in contrast to normal 8 with Image.open("Tests/images/exif-ifd-offset.jpg") as im: # Act / Assert assert im._getexif()[306] == "2017:03:13 23:03:09" def test_photoshop(self): with Image.open("Tests/images/photoshop-200dpi.jpg") as im: assert im.info["photoshop"][0x03ED] == { "XResolution": 200.0, "DisplayedUnitsX": 1, "YResolution": 200.0, "DisplayedUnitsY": 1, } # Test that the image can still load, even with broken Photoshop data # This image had the APP13 length hexedited to be smaller with Image.open("Tests/images/photoshop-200dpi-broken.jpg") as im_broken: assert_image_equal(im_broken, im) # This image does not contain a Photoshop header string with Image.open("Tests/images/app13.jpg") as im: assert "photoshop" not in im.info def test_photoshop_malformed_and_multiple(self): with Image.open("Tests/images/app13-multiple.jpg") as im: assert "photoshop" in im.info assert 24 == len(im.info["photoshop"]) apps_13_lengths = [len(v) for k, v in im.applist if k == "APP13"] assert [65504, 24] == apps_13_lengths def test_icc_after_SOF(self): with Image.open("Tests/images/icc-after-SOF.jpg") as im: assert im.info["icc_profile"] == b"profile" def test_jpeg_magic_number(self): size = 4097 buffer = BytesIO(b"\xFF" * size) # Many xFF bytes buffer.max_pos = 0 orig_read = buffer.read def read(n=-1): res = orig_read(n) buffer.max_pos = max(buffer.max_pos, buffer.tell()) return res buffer.read = read with pytest.raises(UnidentifiedImageError): Image.open(buffer) # Assert the entire file has not been read assert 0 < buffer.max_pos < size @pytest.mark.skipif(not is_win32(), reason="Windows only") @skip_unless_feature("jpg") class TestFileCloseW32: def test_fd_leak(self, tmp_path): tmpfile = str(tmp_path / "temp.jpg") with Image.open("Tests/images/hopper.jpg") as im: im.save(tmpfile) im = Image.open(tmpfile) fp = im.fp assert not fp.closed with pytest.raises(OSError): os.remove(tmpfile) im.load() assert fp.closed # this should not fail, as load should have closed the file. os.remove(tmpfile)