feat: flip images / eq method for image (#360)

flip images

Closes #280.

###Summary of Changes
Images can now be flipped both horizontally and vertically.
Image now has an eq method 

Co-authored-by: daniaHu <129186516+daniaHu@users.noreply.github.com>

---------

Co-authored-by: megalinter-bot <129584137+megalinter-bot@users.noreply.github.com>
Co-authored-by: Alex Senger <91055000+alex-senger@users.noreply.github.com>
Co-authored-by: daniaHu <s5dahuss@uni-bonn.de>
Co-authored-by: Alexander <47296670+Marsmaennchen221@users.noreply.github.com>

src/safeds/data/image/containers/_image.py

@@ -1,9 +1,11 @@
 from __future__ import annotations
 
+import copy
 import io
 from pathlib import Path
-from typing import BinaryIO
+from typing import Any, BinaryIO
 
+import PIL
 from PIL.Image import Image as PillowImage
 from PIL.Image import open as open_image
 
@@ -138,6 +140,24 @@ def to_png_file(self, path: str | Path) -> None:
     # IPython integration
     # ------------------------------------------------------------------------------------------------------------------
 
+    def __eq__(self, other: Any) -> bool:
+        """
+        Compare two images.
+
+        Parameters
+        ----------
+        other: The image to compare to.
+
+        Returns
+        -------
+        equals : bool
+            Whether the two images contain equal pixel data.
+
+        """
+        if not isinstance(other, Image):
+            return NotImplemented
+        return self._image.tobytes() == other._image.tobytes()
+
     def _repr_jpeg_(self) -> bytes | None:
         """
         Return a JPEG image as bytes.
@@ -182,7 +202,7 @@ def _repr_png_(self) -> bytes | None:
 
     def resize(self, new_width: int, new_height: int) -> Image:
         """
-        Return the resized image.
+        Return an image that has been resized to a given size.
 
         Returns
         -------
@@ -200,3 +220,29 @@ def resize(self, new_width: int, new_height: int) -> Image:
         new_image = Image(data, self._format)
         new_image._image = new_image._image.resize((new_width, new_height))
         return new_image
+
+    def flip_vertically(self) -> Image:
+        """
+        Flip the image vertically (horizontal axis, flips up-down and vice versa).
+
+        Returns
+        -------
+        result : Image
+            The flipped image.
+        """
+        imagecopy = copy.deepcopy(self)
+        imagecopy._image = self._image.transpose(PIL.Image.FLIP_TOP_BOTTOM)
+        return imagecopy
+
+    def flip_horizontally(self) -> Image:
+        """
+        Flip the image horizontally (vertical axis, flips left-right and vice versa).
+
+        Returns
+        -------
+        result : Image
+            The flipped image.
+        """
+        imagecopy = copy.deepcopy(self)
+        imagecopy._image = self._image.transpose(PIL.Image.FLIP_LEFT_RIGHT)
+        return imagecopy

tests/safeds/data/image/containers/test_image.py

@@ -4,6 +4,7 @@
 import pytest
 from safeds.data.image.containers import Image
 from safeds.data.image.typing import ImageFormat
+from safeds.data.tabular.containers import Table
 
 from tests.helpers import resolve_resource_path
 
@@ -203,3 +204,46 @@ def test_should_return_resized_image(
         new_size: tuple[int, int],
     ) -> None:
         assert image.resize(new_width, new_height)._image.size == new_size
+
+
+class TestEQ:
+    def test_should_be_equal(self) -> None:
+        image = Image.from_png_file(resolve_resource_path("image/original.png"))
+        image2 = Image.from_png_file(resolve_resource_path("image/copy.png"))
+        assert image == image2
+
+    def test_should_not_be_equal(self) -> None:
+        image = Image.from_png_file(resolve_resource_path("image/original.png"))
+        image2 = Image.from_png_file(resolve_resource_path("image/white_square.png"))
+        assert image != image2
+
+    def test_should_raise(self) -> None:
+        image = Image.from_png_file(resolve_resource_path("image/original.png"))
+        other = Table()
+        assert (image.__eq__(other)) is NotImplemented
+
+
+class TestFlipVertically:
+    def test_should_flip_vertically(self) -> None:
+        image = Image.from_png_file(resolve_resource_path("image/original.png"))
+        image = image.flip_vertically()
+        image2 = Image.from_png_file(resolve_resource_path("image/flip_vertically.png"))
+        assert image == image2
+
+    def test_should_be_original(self) -> None:
+        image = Image.from_png_file(resolve_resource_path("image/original.png"))
+        image2 = image.flip_vertically().flip_vertically()
+        assert image == image2
+
+
+class TestFlipHorizontally:
+    def test_should_flip_horizontally(self) -> None:
+        image = Image.from_png_file(resolve_resource_path("image/original.png"))
+        image = image.flip_horizontally()
+        image2 = Image.from_png_file(resolve_resource_path("image/flip_horizontally.png"))
+        assert image == image2
+
+    def test_should_be_original(self) -> None:
+        image = Image.from_png_file(resolve_resource_path("image/original.png"))
+        image2 = image.flip_horizontally().flip_horizontally()
+        assert image == image2