Pillow/Tests/test_file_libtiff.py

from tester import *
import os

from PIL import Image, TiffImagePlugin

codecs = dir(Image.core)

if "libtiff_encoder" not in codecs or "libtiff_decoder" not in codecs:
    skip("tiff support not available")

def _assert_noerr(im):
    """Helper tests that assert basic sanity about the g4 tiff reading"""
    #1 bit
    assert_equal(im.mode, "1")

    # Does the data actually load
    assert_no_exception(lambda: im.load())
    assert_no_exception(lambda: im.getdata())

    try:
        assert_equal(im._compression, 'group4')
    except:
        print("No _compression")
        print (dir(im))

    # can we write it back out, in a different form.
    out = tempfile("temp.png")
    assert_no_exception(lambda: im.save(out))

def test_g4_tiff():
    """Test the ordinary file path load path"""

    file = "Tests/images/lena_g4_500.tif"
    im = Image.open(file)

    assert_equal(im.size, (500,500))
    _assert_noerr(im)

def test_g4_large():
    file = "Tests/images/pport_g4.tif"
    im = Image.open(file)
    _assert_noerr(im)

def test_g4_tiff_file():
    """Testing the string load path"""

    file = "Tests/images/lena_g4_500.tif"
    with open(file,'rb') as f:
        im = Image.open(f)

        assert_equal(im.size, (500,500))
        _assert_noerr(im)

def test_g4_tiff_bytesio():
    """Testing the stringio loading code path"""
    from io import BytesIO
    file = "Tests/images/lena_g4_500.tif"
    s = BytesIO()
    with open(file,'rb') as f:
        s.write(f.read())
        s.seek(0)
    im = Image.open(s)

    assert_equal(im.size, (500,500))
    _assert_noerr(im)

def test_g4_eq_png():
    """ Checking that we're actually getting the data that we expect"""
    png = Image.open('Tests/images/lena_bw_500.png')
    g4 = Image.open('Tests/images/lena_g4_500.tif')

    assert_image_equal(g4, png)

# see https://github.com/python-imaging/Pillow/issues/279
def test_g4_fillorder_eq_png():
    """ Checking that we're actually getting the data that we expect"""
    png = Image.open('Tests/images/g4-fillorder-test.png')
    g4 = Image.open('Tests/images/g4-fillorder-test.tif')

    assert_image_equal(g4, png)

def test_g4_write():
    """Checking to see that the saved image is the same as what we wrote"""
    file = "Tests/images/lena_g4_500.tif"
    orig = Image.open(file)

    out = tempfile("temp.tif")
    rot = orig.transpose(Image.ROTATE_90)
    assert_equal(rot.size,(500,500))
    rot.save(out)

    reread = Image.open(out)
    assert_equal(reread.size,(500,500))
    _assert_noerr(reread)
    assert_image_equal(reread, rot)
    assert_equal(reread.info['compression'], 'group4')

    assert_equal(reread.info['compression'], orig.info['compression'])
    
    assert_false(orig.tobytes() == reread.tobytes())

def test_adobe_deflate_tiff():
    file = "Tests/images/tiff_adobe_deflate.tif"
    im = Image.open(file)

    assert_equal(im.mode, "RGB")
    assert_equal(im.size, (278, 374))
    assert_equal(im.tile[0][:3], ('tiff_adobe_deflate', (0, 0, 278, 374), 0))
    assert_no_exception(lambda: im.load())

def test_write_metadata():
    """ Test metadata writing through libtiff """
    img = Image.open('Tests/images/lena_g4.tif')
    f = tempfile('temp.tiff')

    img.save(f, tiffinfo = img.tag)

    loaded = Image.open(f)

    original = img.tag.named()
    reloaded = loaded.tag.named()

    # PhotometricInterpretation is set from SAVE_INFO, not the original image. 
    ignored = ['StripByteCounts', 'RowsPerStrip', 'PageNumber', 'PhotometricInterpretation']

    for tag, value in reloaded.items():
        if tag not in ignored:
            if tag.endswith('Resolution'):
                val = original[tag]
                assert_almost_equal(val[0][0]/val[0][1], value[0][0]/value[0][1],
                                    msg="%s didn't roundtrip" % tag)
            else:
                assert_equal(original[tag], value, "%s didn't roundtrip" % tag)

    for tag, value in original.items():
        if tag not in ignored: 
            if tag.endswith('Resolution'):
                val = reloaded[tag]
                assert_almost_equal(val[0][0]/val[0][1], value[0][0]/value[0][1],
                                    msg="%s didn't roundtrip" % tag)
            else:
                assert_equal(value, reloaded[tag], "%s didn't roundtrip" % tag)


def test_g3_compression():
    i = Image.open('Tests/images/lena_g4_500.tif')
    out = tempfile("temp.tif")
    i.save(out, compression='group3')

    reread = Image.open(out)
    assert_equal(reread.info['compression'], 'group3')
    assert_image_equal(reread, i)

def test_little_endian():
    im = Image.open('Tests/images/16bit.deflate.tif')
    assert_equal(im.getpixel((0,0)), 480)
    assert_equal(im.mode, 'I;16')

    b = im.tobytes()
    # Bytes are in image native order (little endian)
    if py3:
        assert_equal(b[0], ord(b'\xe0'))
        assert_equal(b[1], ord(b'\x01'))
    else:
        assert_equal(b[0], b'\xe0')
        assert_equal(b[1], b'\x01')
        

    out = tempfile("temp.tif")
    #out = "temp.le.tif"
    im.save(out)
    reread = Image.open(out)

    assert_equal(reread.info['compression'], im.info['compression'])
    assert_equal(reread.getpixel((0,0)), 480)
    # UNDONE - libtiff defaults to writing in native endian, so
    # on big endian, we'll get back mode = 'I;16B' here. 
    
def test_big_endian():
    im = Image.open('Tests/images/16bit.MM.deflate.tif')

    assert_equal(im.getpixel((0,0)), 480)
    assert_equal(im.mode, 'I;16B')

    b = im.tobytes()

    # Bytes are in image native order (big endian)
    if py3:
        assert_equal(b[0], ord(b'\x01'))
        assert_equal(b[1], ord(b'\xe0'))
    else:
        assert_equal(b[0], b'\x01')
        assert_equal(b[1], b'\xe0')
    
    out = tempfile("temp.tif")
    im.save(out)
    reread = Image.open(out)

    assert_equal(reread.info['compression'], im.info['compression'])
    assert_equal(reread.getpixel((0,0)), 480)

def test_g4_string_info():
    """Tests String data in info directory"""
    file = "Tests/images/lena_g4_500.tif"
    orig = Image.open(file)
    
    out = tempfile("temp.tif")

    orig.tag[269] = 'temp.tif'
    orig.save(out)
             
    reread = Image.open(out)
    assert_equal('temp.tif', reread.tag[269])

def test_12bit_rawmode():
    """ Are we generating the same interpretation of the image as Imagemagick is? """
    TiffImagePlugin.READ_LIBTIFF = True
    #Image.DEBUG = True
    im = Image.open('Tests/images/12bit.cropped.tif')
    im.load()
    TiffImagePlugin.READ_LIBTIFF = False
    # to make the target --
    # convert 12bit.cropped.tif -depth 16 tmp.tif
    # convert tmp.tif -evaluate RightShift 4 12in16bit2.tif
    # imagemagick will auto scale so that a 12bit FFF is 16bit FFF0,
    # so we need to unshift so that the integer values are the same. 
    
    im2 = Image.open('Tests/images/12in16bit.tif')

    if Image.DEBUG:
        print (im.getpixel((0,0)))
        print (im.getpixel((0,1)))
        print (im.getpixel((0,2)))

        print (im2.getpixel((0,0)))
        print (im2.getpixel((0,1)))
        print (im2.getpixel((0,2)))
  
    assert_image_equal(im, im2)

def test_blur():
    # test case from irc, how to do blur on b/w image and save to compressed tif. 
    from PIL import ImageFilter
    out = tempfile('temp.tif')
    im = Image.open('Tests/images/pport_g4.tif')
    im = im.convert('L')

    im=im.filter(ImageFilter.GaussianBlur(4))
    im.save(out, compression='tiff_adobe_deflate')

    im2 = Image.open(out)
    im2.load()

    assert_image_equal(im, im2)


def test_compressions():
    im = lena('RGB')
    out = tempfile('temp.tif')

    for compression in ('packbits', 'tiff_lzw'):
        im.save(out, compression=compression)
        im2 = Image.open(out)
        assert_image_equal(im, im2)

    im.save(out, compression='jpeg')
    im2 = Image.open(out)
    assert_image_similar(im, im2, 30)
                            

def test_cmyk_save():
    im = lena('CMYK')
    out = tempfile('temp.tif')

    im.save(out, compression='tiff_adobe_deflate')
    im2 = Image.open(out)
    assert_image_equal(im, im2)

def xtest_bw_compression_wRGB():
    """ This test passes, but when running all tests causes a failure due to
        output on stderr from the error thrown by libtiff. We need to capture that
        but not now"""
    
    im = lena('RGB')
    out = tempfile('temp.tif')

    assert_exception(IOError, lambda: im.save(out, compression='tiff_ccitt'))
    assert_exception(IOError, lambda: im.save(out, compression='group3'))
    assert_exception(IOError, lambda: im.save(out, compression='group4'))

def test_fp_leak():
    im = Image.open("Tests/images/lena_g4_500.tif")
    fn = im.fp.fileno()

    assert_no_exception(lambda: os.fstat(fn))
    im.load()  # this should close it. 
    assert_exception(OSError, lambda: os.fstat(fn)) 
    im = None  # this should force even more closed.
    assert_exception(OSError, lambda: os.fstat(fn)) 
    assert_exception(OSError, lambda: os.close(fn))