add horizontal/vertical flip

src/flip.rs

@@ -0,0 +1,135 @@
+use crate::image::Image;
+use anyhow::Result;
+
+/// Flip the input image horizontally.
+///
+/// # Arguments
+///
+/// * `image` - The input image with shape (H, W, C).
+///
+/// # Returns
+///
+/// The flipped image.
+///
+/// # Example
+///
+/// ```
+/// use kornia_rs::image::{Image, ImageSize};
+///
+/// let image = Image::<f32, 3>::new(
+///     ImageSize {
+///         width: 2,
+///         height: 3,
+///     },
+///     vec![0f32; 2 * 3 * 3],
+/// )
+/// .unwrap();
+/// let flipped: Image<f32, 3> = kornia_rs::flip::horizontal_flip(&image).unwrap();
+/// assert_eq!(flipped.image_size().width, 2);
+/// assert_eq!(flipped.image_size().height, 3);
+/// ```
+pub fn horizontal_flip<T, const CHANNELS: usize>(
+    image: &Image<T, CHANNELS>,
+) -> Result<Image<T, CHANNELS>>
+where
+    T: Copy,
+{
+    // NOTE: verify that this is efficient
+    let mut img = image.clone();
+
+    img.data
+        .axis_iter_mut(ndarray::Axis(0))
+        .for_each(|mut row| {
+            row.as_slice_mut().unwrap().reverse();
+        });
+
+    Ok(img)
+}
+
+/// Flip the input image vertically.
+///
+/// # Arguments
+///
+/// * `image` - The input image with shape (H, W, C).
+///
+/// # Returns
+///
+/// The flipped image.
+///
+/// # Example
+///
+/// ```
+/// use kornia_rs::image::{Image, ImageSize};
+///
+/// let image = Image::<f32, 3>::new(
+///     ImageSize {
+///         width: 2,
+///         height: 3,
+///     },
+///     vec![0f32; 2 * 3 * 3],
+/// )
+/// .unwrap();
+/// let flipped: Image<f32, 3> = kornia_rs::flip::vertical_flip(&image).unwrap();
+/// assert_eq!(flipped.image_size().width, 2);
+/// assert_eq!(flipped.image_size().height, 3);
+/// ```
+pub fn vertical_flip<T, const CHANNELS: usize>(
+    image: &Image<T, CHANNELS>,
+) -> Result<Image<T, CHANNELS>>
+where
+    T: Copy,
+{
+    let mut img = image.clone();
+
+    img.data
+        .axis_iter_mut(ndarray::Axis(1))
+        .for_each(|mut col| {
+            let mut i = 0;
+            let mut j = image.height() - 1;
+            while i < j {
+                for c in 0..CHANNELS {
+                    col.swap((i, c), (j, c));
+                }
+                i += 1;
+                j -= 1;
+            }
+        });
+
+    Ok(img)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::image::{Image, ImageSize};
+
+    #[test]
+    fn test_hflip() {
+        let image = Image::<_, 1>::new(
+            ImageSize {
+                width: 2,
+                height: 3,
+            },
+            vec![0u8, 1, 2, 3, 4, 5],
+        )
+        .unwrap();
+        let data_expected = vec![1u8, 0, 3, 2, 5, 4];
+        let flipped = horizontal_flip(&image).unwrap();
+        assert_eq!(flipped.data.as_slice().unwrap(), &data_expected);
+    }
+
+    #[test]
+    fn test_vflip() {
+        let image = Image::<_, 1>::new(
+            ImageSize {
+                width: 2,
+                height: 3,
+            },
+            vec![0u8, 1, 2, 3, 4, 5],
+        )
+        .unwrap();
+        let data_expected = vec![4u8, 5, 2, 3, 0, 1];
+        let flipped = vertical_flip(&image).unwrap();
+        assert_eq!(flipped.data.as_slice().unwrap(), &data_expected);
+    }
+}

src/lib.rs

@@ -1,4 +1,6 @@
 pub mod color;
+pub mod distance_transform;
+pub mod flip;
 pub mod image;
 pub mod io;
 pub mod normalize;