feat: Resize image (#354)

Closes #283

### Summary of Changes

* Added a new method `resize` to `Image` that takes parameters
`new_width` and `new_height` and returns a new, resized `Image`. The
original image is not changed.

---------

Co-authored-by: jxnior01 <[email protected]>
Co-authored-by: megalinter-bot <[email protected]>
Co-authored-by: Severin Paul Höfer <[email protected]>

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

@@ -151,3 +151,28 @@ def _repr_png_(self) -> bytes | None:
         self._image.save(buffer, format="png")
         buffer.seek(0)
         return buffer.read()
+
+    # ------------------------------------------------------------------------------------------------------------------
+    # Transformations
+    # ------------------------------------------------------------------------------------------------------------------
+
+    def resize(self, new_width: int, new_height: int) -> Image:
+        """
+        Return the resized image.
+
+        Returns
+        -------
+        result : Image
+            The image with the given width and height
+        """
+        data = io.BytesIO()
+        repr_png = self._repr_png_()
+        repr_jpeg = self._repr_jpeg_()
+        if repr_png is not None:
+            data = io.BytesIO(repr_png)
+        elif repr_jpeg is not None:
+            data = io.BytesIO(repr_jpeg)
+
+        new_image = Image(data, self._format)
+        new_image._image = new_image._image.resize((new_width, new_height))
+        return new_image

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

@@ -152,3 +152,32 @@ def test_should_return_bytes_if_image_is_png(self, image: Image) -> None:
     )
     def test_should_return_none_if_image_is_not_png(self, image: Image) -> None:
         assert image._repr_png_() is None
+
+
+class TestResize:
+    @pytest.mark.parametrize(
+        ("image", "new_width", "new_height", "new_size"),
+        [
+            (
+                Image.from_jpeg_file(resolve_resource_path("image/white_square.jpg")),
+                2,
+                3,
+                (2, 3),
+            ),
+            (
+                Image.from_png_file(resolve_resource_path("image/white_square.png")),
+                2,
+                3,
+                (2, 3),
+            ),
+        ],
+        ids=[".jpg", ".png"],
+    )
+    def test_should_return_resized_image(
+        self,
+        image: Image,
+        new_width: int,
+        new_height: int,
+        new_size: tuple[int, int],
+    ) -> None:
+        assert image.resize(new_width, new_height)._image.size == new_size