diff --git a/Tests/test_lib_image.py b/Tests/test_lib_image.py index 31548bbc91f..438ecd5caf9 100644 --- a/Tests/test_lib_image.py +++ b/Tests/test_lib_image.py @@ -1,5 +1,7 @@ from __future__ import annotations +import itertools + import pytest from PIL import Image @@ -32,3 +34,62 @@ def test_setmode() -> None: im.im.setmode("L") with pytest.raises(ValueError): im.im.setmode("RGBABCDE") + + +@pytest.mark.parametrize("mode", Image.MODES) +def test_equal(mode): + num_img_bytes = len(Image.new(mode, (2, 2)).tobytes()) + data = bytes(range(ord("A"), ord("A") + num_img_bytes)) + img_a = Image.frombytes(mode, (2, 2), data) + img_b = Image.frombytes(mode, (2, 2), data) + assert img_a.tobytes() == img_b.tobytes() + assert img_a.im == img_b.im + + +# With mode "1" different bytes can map to the same value, +# so we have to be more specific with the values we use. +@pytest.mark.parametrize( + "bytes_a, bytes_b", + itertools.permutations( + (bytes(x) for x in itertools.product(b"\x00\xff", repeat=4)), 2 + ), +) +def test_not_equal_mode_1(bytes_a, bytes_b): + # Use rawmode "1;8" so that each full byte is interpreted as a value + # instead of the bits in the bytes being interpreted as values. + img_a = Image.frombytes("1", (2, 2), bytes_a, "raw", "1;8") + img_b = Image.frombytes("1", (2, 2), bytes_b, "raw", "1;8") + assert img_a.tobytes() != img_b.tobytes() + assert img_a.im != img_b.im + + +@pytest.mark.parametrize("mode", [mode for mode in Image.MODES if mode != "1"]) +def test_not_equal(mode): + num_img_bytes = len(Image.new(mode, (2, 2)).tobytes()) + data_a = bytes(range(ord("A"), ord("A") + num_img_bytes)) + data_b = bytes(range(ord("Z"), ord("Z") - num_img_bytes, -1)) + img_a = Image.frombytes(mode, (2, 2), data_a) + img_b = Image.frombytes(mode, (2, 2), data_b) + assert img_a.tobytes() != img_b.tobytes() + assert img_a.im != img_b.im + + +@pytest.mark.parametrize("mode", ("RGB", "YCbCr", "HSV", "LAB")) +def test_equal_three_channels_four_bytes(mode): + # The "A" and "B" values in LAB images are signed values from -128 to 127, + # but we store them as unsigned values from 0 to 255, so we need to use + # slightly different input bytes for LAB to get the same output. + img_a = Image.new(mode, (1, 1), 0x00B3B231 if mode == "LAB" else 0x00333231) + img_b = Image.new(mode, (1, 1), 0xFFB3B231 if mode == "LAB" else 0xFF333231) + assert img_a.tobytes() == b"123" + assert img_b.tobytes() == b"123" + assert img_a.im == img_b.im + + +@pytest.mark.parametrize("mode", ("LA", "La", "PA")) +def test_equal_two_channels_four_bytes(mode): + img_a = Image.new(mode, (1, 1), 0x32000031) + img_b = Image.new(mode, (1, 1), 0x32FFFF31) + assert img_a.tobytes() == b"12" + assert img_b.tobytes() == b"12" + assert img_a.im == img_b.im diff --git a/src/PIL/Image.py b/src/PIL/Image.py index 6a2aa3e4cd1..b53cf3c7b76 100644 --- a/src/PIL/Image.py +++ b/src/PIL/Image.py @@ -668,13 +668,17 @@ def __eq__(self, other: object) -> bool: if self.__class__ is not other.__class__: return False assert isinstance(other, Image) - return ( + if self is other: + return True + if not ( self.mode == other.mode and self.size == other.size and self.info == other.info - and self.getpalette() == other.getpalette() - and self.tobytes() == other.tobytes() - ) + ): + return False + self.load() + other.load() + return self.im == other.im def __repr__(self) -> str: return ( diff --git a/src/_imaging.c b/src/_imaging.c index fa38dcc0586..595d8930f8f 100644 --- a/src/_imaging.c +++ b/src/_imaging.c @@ -3766,6 +3766,130 @@ static PySequenceMethods image_as_sequence = { (ssizessizeobjargproc)NULL, /*sq_ass_slice*/ }; +/* +Returns 0 if all of the pixels are the same, otherwise 1. +Skips unused bytes based on the given mode. +*/ +static int +_compare_pixels( + const char *mode, + const int ysize, + const int linesize, + const UINT8 **pixels_a, + const UINT8 **pixels_b +) { + // Fortunately, all of the modes that have extra bytes in their pixels + // use four bytes for their pixels. + UINT32 mask = 0xffffffff; + if (!strcmp(mode, "RGB") || !strcmp(mode, "YCbCr") || !strcmp(mode, "HSV") || + !strcmp(mode, "LAB")) { + // These modes have three channels in four bytes, + // so we have to ignore the last byte. +#ifdef WORDS_BIGENDIAN + mask = 0xffffff00; +#else + mask = 0x00ffffff; +#endif + } else if (!strcmp(mode, "LA") || !strcmp(mode, "La") || !strcmp(mode, "PA")) { + // These modes have two channels in four bytes, + // so we have to ignore the middle two bytes. + mask = 0xff0000ff; + } + + if (mask == 0xffffffff) { + // If we aren't masking anything we can use memcmp. + for (int y = 0; y < ysize; y++) { + if (memcmp(pixels_a[y], pixels_b[y], linesize)) { + return 1; + } + } + } else { + const int xsize = linesize / 4; + for (int y = 0; y < ysize; y++) { + UINT32 *line_a = (UINT32 *)pixels_a[y]; + UINT32 *line_b = (UINT32 *)pixels_b[y]; + for (int x = 0; x < xsize; x++, line_a++, line_b++) { + if ((*line_a & mask) != (*line_b & mask)) { + return 1; + } + } + } + } + return 0; +} + +static PyObject * +image_richcompare(const ImagingObject *self, const PyObject *other, const int op) { + if (op != Py_EQ && op != Py_NE) { + Py_RETURN_NOTIMPLEMENTED; + } + + // If the other object is not an ImagingObject. + if (!PyImaging_Check(other)) { + if (op == Py_EQ) { + Py_RETURN_FALSE; + } else { + Py_RETURN_TRUE; + } + } + + const Imaging img_a = self->image; + const Imaging img_b = ((ImagingObject *)other)->image; + + if (strcmp(img_a->mode, img_b->mode) || img_a->xsize != img_b->xsize || + img_a->ysize != img_b->ysize) { + if (op == Py_EQ) { + Py_RETURN_FALSE; + } else { + Py_RETURN_TRUE; + } + } + + const ImagingPalette palette_a = img_a->palette; + const ImagingPalette palette_b = img_b->palette; + if (palette_a || palette_b) { + const UINT8 *palette_a_data = palette_a->palette; + const UINT8 *palette_b_data = palette_b->palette; + const UINT8 **palette_a_data_ptr = &palette_a_data; + const UINT8 **palette_b_data_ptr = &palette_b_data; + if (!palette_a || !palette_b || palette_a->size != palette_b->size || + strcmp(palette_a->mode, palette_b->mode) || + _compare_pixels( + palette_a->mode, + 1, + palette_a->size * 4, + palette_a_data_ptr, + palette_b_data_ptr + )) { + if (op == Py_EQ) { + Py_RETURN_FALSE; + } else { + Py_RETURN_TRUE; + } + } + } + + if (_compare_pixels( + img_a->mode, + img_a->ysize, + img_a->linesize, + (const UINT8 **)img_a->image, + (const UINT8 **)img_b->image + )) { + if (op == Py_EQ) { + Py_RETURN_FALSE; + } else { + Py_RETURN_TRUE; + } + } else { + if (op == Py_EQ) { + Py_RETURN_TRUE; + } else { + Py_RETURN_FALSE; + } + } +} + /* type description */ static PyTypeObject Imaging_Type = { @@ -3773,6 +3897,7 @@ static PyTypeObject Imaging_Type = { .tp_basicsize = sizeof(ImagingObject), .tp_dealloc = (destructor)_dealloc, .tp_as_sequence = &image_as_sequence, + .tp_richcompare = (richcmpfunc)image_richcompare, .tp_methods = methods, .tp_getset = getsetters, };