bendns' repos / remapper
Diffstat (limited to 'src/diffusion.rs')
-rw-r--r--src/diffusion.rs112
1 files changed, 112 insertions, 0 deletions
diff --git a/src/diffusion.rs b/src/diffusion.rs
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+++ b/src/diffusion.rs
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+//! # Error diffusion dithering.
+//! The way this works is by finding the amount of error between the quantized color and the original color, and offseting the error to the (next) neighboring pixels.
+//! Which neighboring pixels depend on the algorithm chosen.
+use super::*;
+mod riemerasma;
+pub mod sierra;
+pub use riemerasma::*;
+pub fn atkinson(image: Image<&[f32], 4>, palette: &[[f32; 4]]) -> Image<Box<[f32]>, 4> {
+ let kd = map(palette);
+ let mut image =
+ Image::build(image.width(), image.height()).buf(image.buffer().to_vec().into_boxed_slice());
+ let w = image.width();
+ let h = image.height();
+ let eighth = [1. / 8.; 4];
+ for (x, y) in (0..h).flat_map(move |y| (0..w).map(move |x| (x, y))) {
+ unsafe {
+ /*
+ * 1 1
+ 1 1 1
+ 1
+ */
+ let p = image.pixel(x, y);
+ let new = palette[kd.find_nearest(p) as usize];
+ *image.pixel_mut(x, y) = new;
+ let error = p.asub(new);
+ let f = |x: [f32; 4]| x.aadd(error.amul(eighth));
+ image.replace(x + 1, y, f);
+ image.replace(x + 2, y, f);
+
+ image.replace(x.wrapping_sub(1), y + 1, f);
+ image.replace(x, y + 1, f);
+ image.replace(x + 1, y + 1, f);
+
+ image.replace(x, y + 2, f);
+ }
+ }
+ image
+}
+
+pub fn jarvis<const FAC: u8>(
+ image: Image<&[f32], 4>,
+ palette: &[[f32; 4]],
+) -> Image<Box<[f32]>, 4> {
+ let kd = map(palette);
+ let mut image =
+ Image::build(image.width(), image.height()).buf(image.buffer().to_vec().into_boxed_slice());
+ let w = image.width();
+ let h = image.height();
+ for (x, y) in (0..h).flat_map(move |y| (0..w).map(move |x| (x, y))) {
+ #[rustfmt::skip]
+ unsafe {
+ let p = image.pixel(x, y);
+ let new = palette[kd.find_nearest(p) as usize];
+ *image.pixel_mut(x, y) = new;
+ let error = p.asub(new);
+ let f = |f| {
+ move |x: [f32; 4]| {
+ x.aadd(error.amul([(f as f32 / 48.) * const { FAC as f32 * (1.0 / 255.) }; 4]))
+ }
+ };
+ /* * 7 5
+ 3 5 7 5 3
+ 1 3 5 3 1*/
+ image.replace(x + 1, y, f(7));
+ image.replace(x + 2, y, f(5));
+ let y = y + 1;
+ image.replace(x.wrapping_sub(2), y, f(3));
+ image.replace(x.wrapping_sub(1), y, f(5));
+ image.replace(x , y, f(7));
+ image.replace(x + 1, y, f(5));
+ image.replace(x + 2, y, f(3));
+ let y = y + 1;
+ image.replace(x.wrapping_sub(2), y, f(1));
+ image.replace(x.wrapping_sub(1), y, f(3));
+ image.replace(x , y, f(5));
+ image.replace(x + 1, y, f(3));
+ image.replace(x + 2, y, f(1));
+ }
+ }
+ image
+}
+pub fn floyd_steinberg<const FAC: u8>(
+ image: Image<&[f32], 4>,
+ palette: &[[f32; 4]],
+) -> Image<Box<[f32]>, 4> {
+ let kd = map(palette);
+ let mut image =
+ Image::build(image.width(), image.height()).buf(image.buffer().to_vec().into_boxed_slice());
+ let w = image.width();
+ let h = image.height();
+ for (x, y) in (0..h).flat_map(move |y| (0..w).map(move |x| (x, y))) {
+ unsafe {
+ let p = image.pixel(x, y);
+ let new = palette[kd.find_nearest(p) as usize];
+ *image.pixel_mut(x, y) = new;
+ let error = p.asub(new);
+ let f = |f| {
+ move |x: [f32; 4]| {
+ x.aadd(error.amul([(f as f32 / 48.) * const { FAC as f32 * (1.0 / 255.) }; 4]))
+ }
+ };
+ /*
+ * 7
+ 3 5 1 */
+ image.replace(x + 1, y, f(7));
+ image.replace(x.wrapping_sub(1), y + 1, f(3));
+ image.replace(x, y + 1, f(5));
+ image.replace(x + 1, y + 1, f(1));
+ }
+ }
+ image
+}