diff options
Diffstat (limited to 'third_party/rust/image/src/imageops')
| -rw-r--r-- | third_party/rust/image/src/imageops/affine.rs | 387 | ||||
| -rw-r--r-- | third_party/rust/image/src/imageops/colorops.rs | 325 | ||||
| -rw-r--r-- | third_party/rust/image/src/imageops/mod.rs | 219 | ||||
| -rw-r--r-- | third_party/rust/image/src/imageops/sample.rs | 873 |
4 files changed, 1804 insertions, 0 deletions
diff --git a/third_party/rust/image/src/imageops/affine.rs b/third_party/rust/image/src/imageops/affine.rs new file mode 100644 index 0000000000..adaa8b995b --- /dev/null +++ b/third_party/rust/image/src/imageops/affine.rs @@ -0,0 +1,387 @@ +//! Functions for performing affine transformations. + +use crate::buffer::{ImageBuffer, Pixel}; +use crate::image::{GenericImage, GenericImageView}; + +/// Rotate an image 90 degrees clockwise. +pub fn rotate90<I: GenericImageView>( + image: &I, +) -> ImageBuffer<I::Pixel, Vec<<I::Pixel as Pixel>::Subpixel>> + where I::Pixel: 'static, +{ + let (width, height) = image.dimensions(); + let mut out = ImageBuffer::new(height, width); + let _ = rotate90_in(image, &mut out); + out +} + +/// Rotate an image 180 degrees clockwise. +pub fn rotate180<I: GenericImageView>( + image: &I, +) -> ImageBuffer<I::Pixel, Vec<<I::Pixel as Pixel>::Subpixel>> + where I::Pixel: 'static, +{ + let (width, height) = image.dimensions(); + let mut out = ImageBuffer::new(width, height); + let _ = rotate180_in(image, &mut out); + out +} + +/// Rotate an image 270 degrees clockwise. +pub fn rotate270<I: GenericImageView>( + image: &I, +) -> ImageBuffer<I::Pixel, Vec<<I::Pixel as Pixel>::Subpixel>> + where I::Pixel: 'static, +{ + let (width, height) = image.dimensions(); + let mut out = ImageBuffer::new(height, width); + let _ = rotate270_in(image, &mut out); + out +} + +/// Rotate an image 90 degrees clockwise and put the result into the destination [`ImageBuffer`]. +pub fn rotate90_in<I, Container>( + image: &I, + destination: &mut ImageBuffer<I::Pixel, Container> +) -> crate::ImageResult<()> where + I: GenericImageView, + I::Pixel: 'static, + Container: std::ops::DerefMut<Target = [<I::Pixel as Pixel>::Subpixel]> +{ + let ((w0, h0), (w1, h1)) = (image.dimensions(), destination.dimensions()); + if w0 != h1 || h0 != w1 { + return Err(crate::ImageError::DimensionError); + } + + for y in 0..h0 { + for x in 0..w0 { + let p = image.get_pixel(x, y); + destination.put_pixel(h0 - y - 1, x, p); + } + } + Ok(()) +} + +/// Rotate an image 180 degrees clockwise and put the result into the destination [`ImageBuffer`]. +pub fn rotate180_in<I, Container>( + image: &I, + destination: &mut ImageBuffer<I::Pixel, Container> +) -> crate::ImageResult<()> where + I: GenericImageView, + I::Pixel: 'static, + Container: std::ops::DerefMut<Target = [<I::Pixel as Pixel>::Subpixel]> +{ + let ((w0, h0), (w1, h1)) = (image.dimensions(), destination.dimensions()); + if w0 != w1 || h0 != h1 { + return Err(crate::ImageError::DimensionError); + } + + for y in 0..h0 { + for x in 0..w0 { + let p = image.get_pixel(x, y); + destination.put_pixel(w0 - x - 1, h0 - y - 1, p); + } + } + Ok(()) +} + +/// Rotate an image 270 degrees clockwise and put the result into the destination [`ImageBuffer`]. +pub fn rotate270_in<I, Container>( + image: &I, + destination: &mut ImageBuffer<I::Pixel, Container> +) -> crate::ImageResult<()> where + I: GenericImageView, + I::Pixel: 'static, + Container: std::ops::DerefMut<Target = [<I::Pixel as Pixel>::Subpixel]> +{ + let ((w0, h0), (w1, h1)) = (image.dimensions(), destination.dimensions()); + if w0 != h1 || h0 != w1 { + return Err(crate::ImageError::DimensionError); + } + + for y in 0..h0 { + for x in 0..w0 { + let p = image.get_pixel(x, y); + destination.put_pixel(y, w0 - x - 1, p); + } + } + Ok(()) +} + +/// Flip an image horizontally +pub fn flip_horizontal<I: GenericImageView>( + image: &I, +) -> ImageBuffer<I::Pixel, Vec<<I::Pixel as Pixel>::Subpixel>> + where I::Pixel: 'static, +{ + let (width, height) = image.dimensions(); + let mut out = ImageBuffer::new(width, height); + let _ = flip_horizontal_in(image, &mut out); + out +} + +/// Flip an image vertically +pub fn flip_vertical<I: GenericImageView>( + image: &I, +) -> ImageBuffer<I::Pixel, Vec<<I::Pixel as Pixel>::Subpixel>> + where I::Pixel: 'static, +{ + let (width, height) = image.dimensions(); + let mut out = ImageBuffer::new(width, height); + let _ = flip_vertical_in(image, &mut out); + out +} + +/// Flip an image horizontally and put the result into the destination [`ImageBuffer`]. +pub fn flip_horizontal_in<I, Container>( + image: &I, + destination: &mut ImageBuffer<I::Pixel, Container> +) -> crate::ImageResult<()> where + I: GenericImageView, + I::Pixel: 'static, + Container: std::ops::DerefMut<Target = [<I::Pixel as Pixel>::Subpixel]> +{ + let ((w0, h0), (w1, h1)) = (image.dimensions(), destination.dimensions()); + if w0 != w1 || h0 != h1 { + return Err(crate::ImageError::DimensionError); + } + + for y in 0..h0 { + for x in 0..w0 { + let p = image.get_pixel(x, y); + destination.put_pixel(w0 - x - 1, y, p); + } + } + Ok(()) +} + +/// Flip an image vertically and put the result into the destination [`ImageBuffer`]. +pub fn flip_vertical_in<I, Container>( + image: &I, + destination: &mut ImageBuffer<I::Pixel, Container> +) -> crate::ImageResult<()> where + I: GenericImageView, + I::Pixel: 'static, + Container: std::ops::DerefMut<Target = [<I::Pixel as Pixel>::Subpixel]> +{ + let ((w0, h0), (w1, h1)) = (image.dimensions(), destination.dimensions()); + if w0 != w1 || h0 != h1 { + return Err(crate::ImageError::DimensionError); + } + + for y in 0..h0 { + for x in 0..w0 { + let p = image.get_pixel(x, y); + destination.put_pixel(x, h0 - 1 - y, p); + } + } + Ok(()) +} + +/// Rotate an image 180 degrees clockwise in place. +pub fn rotate180_in_place<I: GenericImage>(image: &mut I) { + let (width, height) = image.dimensions(); + + for y in 0..height / 2 { + for x in 0..width { + let p = image.get_pixel(x, y); + + let x2 = width - x - 1; + let y2 = height - y - 1; + + let p2 = image.get_pixel(x2, y2); + image.put_pixel(x, y, p2); + image.put_pixel(x2, y2, p); + } + } + + if height % 2 != 0 { + let middle = height / 2; + + for x in 0..width / 2 { + let p = image.get_pixel(x, middle); + let x2 = width - x - 1; + + let p2 = image.get_pixel(x2, middle); + image.put_pixel(x, middle, p2); + image.put_pixel(x2, middle, p); + } + } +} + +/// Flip an image horizontally in place. +pub fn flip_horizontal_in_place<I: GenericImage>(image: &mut I) { + let (width, height) = image.dimensions(); + + for y in 0..height { + for x in 0..width / 2 { + let x2 = width - x - 1; + let p2 = image.get_pixel(x2, y); + let p = image.get_pixel(x, y); + image.put_pixel(x2, y, p); + image.put_pixel(x, y, p2); + } + } +} + +/// Flip an image vertically in place. +pub fn flip_vertical_in_place<I: GenericImage>(image: &mut I) { + let (width, height) = image.dimensions(); + + for y in 0..height / 2 { + for x in 0..width { + let y2 = height - y - 1; + let p2 = image.get_pixel(x, y2); + let p = image.get_pixel(x, y); + image.put_pixel(x, y2, p); + image.put_pixel(x, y, p2); + } + } +} + +#[cfg(test)] +mod test { + use super::{ + flip_horizontal, flip_horizontal_in_place, flip_vertical, flip_vertical_in_place, + rotate180, rotate180_in_place, rotate270, rotate90, + }; + use crate::buffer::{GrayImage, ImageBuffer, Pixel}; + use crate::image::GenericImage; + + macro_rules! assert_pixels_eq { + ($actual:expr, $expected:expr) => {{ + let actual_dim = $actual.dimensions(); + let expected_dim = $expected.dimensions(); + + if actual_dim != expected_dim { + panic!( + "dimensions do not match. \ + actual: {:?}, expected: {:?}", + actual_dim, expected_dim + ) + } + + let diffs = pixel_diffs($actual, $expected); + + if !diffs.is_empty() { + let mut err = "pixels do not match. ".to_string(); + + let diff_messages = diffs + .iter() + .take(5) + .map(|d| format!("\nactual: {:?}, expected {:?} ", d.0, d.1)) + .collect::<Vec<_>>() + .join(""); + + err.push_str(&diff_messages); + panic!(err) + } + }}; + } + + #[test] + fn test_rotate90() { + let image: GrayImage = + ImageBuffer::from_raw(3, 2, vec![00u8, 01u8, 02u8, 10u8, 11u8, 12u8]).unwrap(); + + let expected: GrayImage = + ImageBuffer::from_raw(2, 3, vec![10u8, 00u8, 11u8, 01u8, 12u8, 02u8]).unwrap(); + + assert_pixels_eq!(&rotate90(&image), &expected); + } + + #[test] + fn test_rotate180() { + let image: GrayImage = + ImageBuffer::from_raw(3, 2, vec![00u8, 01u8, 02u8, 10u8, 11u8, 12u8]).unwrap(); + + let expected: GrayImage = + ImageBuffer::from_raw(3, 2, vec![12u8, 11u8, 10u8, 02u8, 01u8, 00u8]).unwrap(); + + assert_pixels_eq!(&rotate180(&image), &expected); + } + + #[test] + fn test_rotate270() { + let image: GrayImage = + ImageBuffer::from_raw(3, 2, vec![00u8, 01u8, 02u8, 10u8, 11u8, 12u8]).unwrap(); + + let expected: GrayImage = + ImageBuffer::from_raw(2, 3, vec![02u8, 12u8, 01u8, 11u8, 00u8, 10u8]).unwrap(); + + assert_pixels_eq!(&rotate270(&image), &expected); + } + + #[test] + fn test_rotate180_in_place() { + let mut image: GrayImage = + ImageBuffer::from_raw(3, 2, vec![00u8, 01u8, 02u8, 10u8, 11u8, 12u8]).unwrap(); + + let expected: GrayImage = + ImageBuffer::from_raw(3, 2, vec![12u8, 11u8, 10u8, 02u8, 01u8, 00u8]).unwrap(); + + rotate180_in_place(&mut image); + + assert_pixels_eq!(&image, &expected); + } + + #[test] + fn test_flip_horizontal() { + let image: GrayImage = + ImageBuffer::from_raw(3, 2, vec![00u8, 01u8, 02u8, 10u8, 11u8, 12u8]).unwrap(); + + let expected: GrayImage = + ImageBuffer::from_raw(3, 2, vec![02u8, 01u8, 00u8, 12u8, 11u8, 10u8]).unwrap(); + + assert_pixels_eq!(&flip_horizontal(&image), &expected); + } + + #[test] + fn test_flip_vertical() { + let image: GrayImage = + ImageBuffer::from_raw(3, 2, vec![00u8, 01u8, 02u8, 10u8, 11u8, 12u8]).unwrap(); + + let expected: GrayImage = + ImageBuffer::from_raw(3, 2, vec![10u8, 11u8, 12u8, 00u8, 01u8, 02u8]).unwrap(); + + assert_pixels_eq!(&flip_vertical(&image), &expected); + } + + #[test] + fn test_flip_horizontal_in_place() { + let mut image: GrayImage = + ImageBuffer::from_raw(3, 2, vec![00u8, 01u8, 02u8, 10u8, 11u8, 12u8]).unwrap(); + + let expected: GrayImage = + ImageBuffer::from_raw(3, 2, vec![02u8, 01u8, 00u8, 12u8, 11u8, 10u8]).unwrap(); + + flip_horizontal_in_place(&mut image); + + assert_pixels_eq!(&image, &expected); + } + + #[test] + fn test_flip_vertical_in_place() { + let mut image: GrayImage = + ImageBuffer::from_raw(3, 2, vec![00u8, 01u8, 02u8, 10u8, 11u8, 12u8]).unwrap(); + + let expected: GrayImage = + ImageBuffer::from_raw(3, 2, vec![10u8, 11u8, 12u8, 00u8, 01u8, 02u8]).unwrap(); + + flip_vertical_in_place(&mut image); + + assert_pixels_eq!(&image, &expected); + } + + fn pixel_diffs<I, J, P>(left: &I, right: &J) -> Vec<((u32, u32, P), (u32, u32, P))> + where + I: GenericImage<Pixel = P>, + J: GenericImage<Pixel = P>, + P: Pixel + Eq, + { + left.pixels() + .zip(right.pixels()) + .filter(|&(p, q)| p != q) + .collect::<Vec<_>>() + } +} diff --git a/third_party/rust/image/src/imageops/colorops.rs b/third_party/rust/image/src/imageops/colorops.rs new file mode 100644 index 0000000000..2de5194957 --- /dev/null +++ b/third_party/rust/image/src/imageops/colorops.rs @@ -0,0 +1,325 @@ +//! Functions for altering and converting the color of pixelbufs + +use crate::buffer::{ImageBuffer, Pixel}; +use crate::color::{Luma, Rgba}; +use crate::image::{GenericImage, GenericImageView}; +use crate::math::nq; +use crate::math::utils::clamp; +use num_traits::{Num, NumCast}; +use std::f64::consts::PI; +use crate::traits::Primitive; + +type Subpixel<I> = <<I as GenericImageView>::Pixel as Pixel>::Subpixel; + +/// Convert the supplied image to grayscale +pub fn grayscale<I: GenericImageView>( + image: &I, +) -> ImageBuffer<Luma<Subpixel<I>>, Vec<Subpixel<I>>> +where + Subpixel<I>: 'static, + <Subpixel<I> as Num>::FromStrRadixErr: 'static, +{ + let (width, height) = image.dimensions(); + let mut out = ImageBuffer::new(width, height); + + for y in 0..height { + for x in 0..width { + let p = image.get_pixel(x, y).to_luma(); + out.put_pixel(x, y, p); + } + } + + out +} + +/// Invert each pixel within the supplied image. +/// This function operates in place. +pub fn invert<I: GenericImage>(image: &mut I) { + let (width, height) = image.dimensions(); + + for y in 0..height { + for x in 0..width { + let mut p = image.get_pixel(x, y); + p.invert(); + + image.put_pixel(x, y, p); + } + } +} + +/// Adjust the contrast of the supplied image. +/// ```contrast``` is the amount to adjust the contrast by. +/// Negative values decrease the contrast and positive values increase the contrast. +pub fn contrast<I, P, S>(image: &I, contrast: f32) -> ImageBuffer<P, Vec<S>> +where + I: GenericImageView<Pixel = P>, + P: Pixel<Subpixel = S> + 'static, + S: Primitive + 'static, +{ + let (width, height) = image.dimensions(); + let mut out = ImageBuffer::new(width, height); + + let max = S::max_value(); + let max: f32 = NumCast::from(max).unwrap(); + + let percent = ((100.0 + contrast) / 100.0).powi(2); + + for y in 0..height { + for x in 0..width { + let f = image.get_pixel(x, y).map(|b| { + let c: f32 = NumCast::from(b).unwrap(); + + let d = ((c / max - 0.5) * percent + 0.5) * max; + let e = clamp(d, 0.0, max); + + NumCast::from(e).unwrap() + }); + + out.put_pixel(x, y, f); + } + } + + out +} + +/// Brighten the supplied image. +/// ```value``` is the amount to brighten each pixel by. +/// Negative values decrease the brightness and positive values increase it. +pub fn brighten<I, P, S>(image: &I, value: i32) -> ImageBuffer<P, Vec<S>> +where + I: GenericImageView<Pixel = P>, + P: Pixel<Subpixel = S> + 'static, + S: Primitive + 'static, +{ + let (width, height) = image.dimensions(); + let mut out = ImageBuffer::new(width, height); + + let max = S::max_value(); + let max: i32 = NumCast::from(max).unwrap(); + + for y in 0..height { + for x in 0..width { + let e = image.get_pixel(x, y).map_with_alpha( + |b| { + let c: i32 = NumCast::from(b).unwrap(); + let d = clamp(c + value, 0, max); + + NumCast::from(d).unwrap() + }, + |alpha| alpha, + ); + + out.put_pixel(x, y, e); + } + } + + out +} + +/// Hue rotate the supplied image. +/// `value` is the degrees to rotate each pixel by. +/// 0 and 360 do nothing, the rest rotates by the given degree value. +/// just like the css webkit filter hue-rotate(180) +pub fn huerotate<I, P, S>(image: &I, value: i32) -> ImageBuffer<P, Vec<S>> +where + I: GenericImageView<Pixel = P>, + P: Pixel<Subpixel = S> + 'static, + S: Primitive + 'static, +{ + let (width, height) = image.dimensions(); + let mut out = ImageBuffer::new(width, height); + + let angle: f64 = NumCast::from(value).unwrap(); + + let cosv = (angle * PI / 180.0).cos(); + let sinv = (angle * PI / 180.0).sin(); + let matrix: [f64; 9] = [ + // Reds + 0.213 + cosv * 0.787 - sinv * 0.213, + 0.715 - cosv * 0.715 - sinv * 0.715, + 0.072 - cosv * 0.072 + sinv * 0.928, + // Greens + 0.213 - cosv * 0.213 + sinv * 0.143, + 0.715 + cosv * 0.285 + sinv * 0.140, + 0.072 - cosv * 0.072 - sinv * 0.283, + // Blues + 0.213 - cosv * 0.213 - sinv * 0.787, + 0.715 - cosv * 0.715 + sinv * 0.715, + 0.072 + cosv * 0.928 + sinv * 0.072, + ]; + for (x, y, pixel) in out.enumerate_pixels_mut() { + let p = image.get_pixel(x, y); + let (k1, k2, k3, k4) = p.channels4(); + let vec: (f64, f64, f64, f64) = ( + NumCast::from(k1).unwrap(), + NumCast::from(k2).unwrap(), + NumCast::from(k3).unwrap(), + NumCast::from(k4).unwrap(), + ); + + let r = vec.0; + let g = vec.1; + let b = vec.2; + + let new_r = matrix[0] * r + matrix[1] * g + matrix[2] * b; + let new_g = matrix[3] * r + matrix[4] * g + matrix[5] * b; + let new_b = matrix[6] * r + matrix[7] * g + matrix[8] * b; + let max = 255f64; + let outpixel = Pixel::from_channels( + NumCast::from(clamp(new_r, 0.0, max)).unwrap(), + NumCast::from(clamp(new_g, 0.0, max)).unwrap(), + NumCast::from(clamp(new_b, 0.0, max)).unwrap(), + NumCast::from(clamp(vec.3, 0.0, max)).unwrap(), + ); + *pixel = outpixel; + } + out +} + +/// A color map +pub trait ColorMap { + /// The color type on which the map operates on + type Color; + /// Returns the index of the closed match of `color` + /// in the color map. + fn index_of(&self, color: &Self::Color) -> usize; + /// Maps `color` to the closest color in the color map. + fn map_color(&self, color: &mut Self::Color); +} + +/// A bi-level color map +#[derive(Clone, Copy)] +pub struct BiLevel; + +impl ColorMap for BiLevel { + type Color = Luma<u8>; + + #[inline(always)] + fn index_of(&self, color: &Luma<u8>) -> usize { + let luma = color.0; + if luma[0] > 127 { + 1 + } else { + 0 + } + } + + #[inline(always)] + fn map_color(&self, color: &mut Luma<u8>) { + let new_color = 0xFF * self.index_of(color) as u8; + let luma = &mut color.0; + luma[0] = new_color; + } +} + +impl ColorMap for nq::NeuQuant { + type Color = Rgba<u8>; + + #[inline(always)] + fn index_of(&self, color: &Rgba<u8>) -> usize { + self.index_of(color.channels()) + } + + #[inline(always)] + fn map_color(&self, color: &mut Rgba<u8>) { + self.map_pixel(color.channels_mut()) + } +} + +/// Floyd-Steinberg error diffusion +fn diffuse_err<P: Pixel<Subpixel = u8>>(pixel: &mut P, error: [i16; 3], factor: i16) { + for (e, c) in error.iter().zip(pixel.channels_mut().iter_mut()) { + *c = match <i16 as From<_>>::from(*c) + e * factor / 16 { + val if val < 0 => 0, + val if val > 0xFF => 0xFF, + val => val as u8, + } + } +} + +macro_rules! do_dithering( + ($map:expr, $image:expr, $err:expr, $x:expr, $y:expr) => ( + { + let old_pixel = $image[($x, $y)]; + let new_pixel = $image.get_pixel_mut($x, $y); + $map.map_color(new_pixel); + for ((e, &old), &new) in $err.iter_mut() + .zip(old_pixel.channels().iter()) + .zip(new_pixel.channels().iter()) + { + *e = <i16 as From<_>>::from(old) - <i16 as From<_>>::from(new) + } + } + ) +); + +/// Reduces the colors of the image using the supplied `color_map` while applying +/// Floyd-Steinberg dithering to improve the visual conception +pub fn dither<Pix, Map>(image: &mut ImageBuffer<Pix, Vec<u8>>, color_map: &Map) +where + Map: ColorMap<Color = Pix>, + Pix: Pixel<Subpixel = u8> + 'static, +{ + let (width, height) = image.dimensions(); + let mut err: [i16; 3] = [0; 3]; + for y in 0..height - 1 { + let x = 0; + do_dithering!(color_map, image, err, x, y); + diffuse_err(image.get_pixel_mut(x + 1, y), err, 7); + diffuse_err(image.get_pixel_mut(x, y + 1), err, 5); + diffuse_err(image.get_pixel_mut(x + 1, y + 1), err, 1); + for x in 1..width - 1 { + do_dithering!(color_map, image, err, x, y); + diffuse_err(image.get_pixel_mut(x + 1, y), err, 7); + diffuse_err(image.get_pixel_mut(x - 1, y + 1), err, 3); + diffuse_err(image.get_pixel_mut(x, y + 1), err, 5); + diffuse_err(image.get_pixel_mut(x + 1, y + 1), err, 1); + } + let x = width - 1; + do_dithering!(color_map, image, err, x, y); + diffuse_err(image.get_pixel_mut(x - 1, y + 1), err, 3); + diffuse_err(image.get_pixel_mut(x, y + 1), err, 5); + } + let y = height - 1; + let x = 0; + do_dithering!(color_map, image, err, x, y); + diffuse_err(image.get_pixel_mut(x + 1, y), err, 7); + for x in 1..width - 1 { + do_dithering!(color_map, image, err, x, y); + diffuse_err(image.get_pixel_mut(x + 1, y), err, 7); + } + let x = width - 1; + do_dithering!(color_map, image, err, x, y); +} + +/// Reduces the colors using the supplied `color_map` and returns an image of the indices +pub fn index_colors<Pix, Map>( + image: &ImageBuffer<Pix, Vec<u8>>, + color_map: &Map, +) -> ImageBuffer<Luma<u8>, Vec<u8>> +where + Map: ColorMap<Color = Pix>, + Pix: Pixel<Subpixel = u8> + 'static, +{ + let mut indices = ImageBuffer::new(image.width(), image.height()); + for (pixel, idx) in image.pixels().zip(indices.pixels_mut()) { + *idx = Luma([color_map.index_of(pixel) as u8]) + } + indices +} + +#[cfg(test)] +mod test { + + use super::*; + use crate::ImageBuffer; + + #[test] + fn test_dither() { + let mut image = ImageBuffer::from_raw(2, 2, vec![127, 127, 127, 127]).unwrap(); + let cmap = BiLevel; + dither(&mut image, &cmap); + assert_eq!(&*image, &[0, 0xFF, 0xFF, 0]); + assert_eq!(index_colors(&image, &cmap).into_raw(), vec![0, 1, 1, 0]) + } +} diff --git a/third_party/rust/image/src/imageops/mod.rs b/third_party/rust/image/src/imageops/mod.rs new file mode 100644 index 0000000000..f0c7fe68c8 --- /dev/null +++ b/third_party/rust/image/src/imageops/mod.rs @@ -0,0 +1,219 @@ +//! Image Processing Functions +use std::cmp; + +use crate::image::{GenericImage, GenericImageView, SubImage}; + +use crate::buffer::Pixel; + +pub use self::sample::FilterType; + +pub use self::sample::FilterType::{CatmullRom, Gaussian, Lanczos3, Nearest, Triangle}; + +/// Affine transformations +pub use self::affine::{ + flip_horizontal, flip_horizontal_in_place, flip_vertical, flip_vertical_in_place, rotate180, + rotate180_in_place, rotate270, rotate90, rotate180_in, rotate90_in, rotate270_in, flip_horizontal_in, flip_vertical_in +}; + +/// Image sampling +pub use self::sample::{blur, filter3x3, resize, thumbnail, unsharpen}; + +/// Color operations +pub use self::colorops::{brighten, contrast, dither, grayscale, huerotate, index_colors, invert, + BiLevel, ColorMap}; + +mod affine; +// Public only because of Rust bug: +// https://github.com/rust-lang/rust/issues/18241 +pub mod colorops; +mod sample; + +/// Return a mutable view into an image +pub fn crop<I: GenericImageView>( + image: &mut I, + x: u32, + y: u32, + width: u32, + height: u32, +) -> SubImage<&mut I> { + let (iwidth, iheight) = image.dimensions(); + + let x = cmp::min(x, iwidth); + let y = cmp::min(y, iheight); + + let height = cmp::min(height, iheight - y); + let width = cmp::min(width, iwidth - x); + + SubImage::new(image, x, y, width, height) +} + +/// Calculate the region that can be copied from top to bottom. +/// +/// Given image size of bottom and top image, and a point at which we want to place the top image +/// onto the bottom image, how large can we be? Have to wary of the following issues: +/// * Top might be larger than bottom +/// * Overflows in the computation +/// * Coordinates could be completely out of bounds +/// +/// The main idea is to make use of inequalities provided by the nature of `saturing_add` and +/// `saturating_sub`. These intrinsically validate that all resulting coordinates will be in bounds +/// for both images. +/// +/// We want that all these coordinate accesses are safe: +/// 1. `bottom.get_pixel(x + [0..x_range), y + [0..y_range))` +/// 2. `top.get_pixel([0..x_range), [0..y_range))` +/// +/// Proof that the function provides the necessary bounds for width. Note that all unaugmented math +/// operations are to be read in standard arithmetic, not integer arithmetic. Since no direct +/// integer arithmetic occurs in the implementation, this is unambiguous. +/// +/// ```text +/// Three short notes/lemmata: +/// - Iff `(a - b) <= 0` then `a.saturating_sub(b) = 0` +/// - Iff `(a - b) >= 0` then `a.saturating_sub(b) = a - b` +/// - If `a <= c` then `a.saturating_sub(b) <= c.saturating_sub(b)` +/// +/// 1.1 We show that if `bottom_width <= x`, then `x_range = 0` therefore `x + [0..x_range)` is empty. +/// +/// x_range +/// = (top_width.saturating_add(x).min(bottom_width)).saturating_sub(x) +/// <= bottom_width.saturating_sub(x) +/// +/// bottom_width <= x +/// <==> bottom_width - x <= 0 +/// <==> bottom_width.saturating_sub(x) = 0 +/// ==> x_range <= 0 +/// ==> x_range = 0 +/// +/// 1.2 If `x < bottom_width` then `x + x_range < bottom_width` +/// +/// x + x_range +/// <= x + bottom_width.saturating_sub(x) +/// = x + (bottom_width - x) +/// = bottom_width +/// +/// 2. We show that `x_range <= top_width` +/// +/// x_range +/// = (top_width.saturating_add(x).min(bottom_width)).saturating_sub(x) +/// <= top_width.saturating_add(x).saturating_sub(x) +/// <= (top_wdith + x).saturating_sub(x) +/// = top_width (due to `top_width >= 0` and `x >= 0`) +/// ``` +/// +/// Proof is the same for height. +pub fn overlay_bounds( + (bottom_width, bottom_height): (u32, u32), + (top_width, top_height): (u32, u32), + x: u32, + y: u32 +) + -> (u32, u32) +{ + let x_range = top_width.saturating_add(x) // Calculate max coordinate + .min(bottom_width) // Restrict to lower width + .saturating_sub(x); // Determinate length from start `x` + let y_range = top_height.saturating_add(y) + .min(bottom_height) + .saturating_sub(y); + (x_range, y_range) +} + +/// Overlay an image at a given coordinate (x, y) +pub fn overlay<I, J>(bottom: &mut I, top: &J, x: u32, y: u32) +where + I: GenericImage, + J: GenericImageView<Pixel = I::Pixel>, +{ + let bottom_dims = bottom.dimensions(); + let top_dims = top.dimensions(); + + // Crop our top image if we're going out of bounds + let (range_width, range_height) = overlay_bounds(bottom_dims, top_dims, x, y); + + for top_y in 0..range_height { + for top_x in 0..range_width { + let p = top.get_pixel(top_x, top_y); + let mut bottom_pixel = bottom.get_pixel(x + top_x, y + top_y); + bottom_pixel.blend(&p); + + bottom.put_pixel(x + top_x, y + top_y, bottom_pixel); + } + } +} + +/// Replace the contents of an image at a given coordinate (x, y) +pub fn replace<I, J>(bottom: &mut I, top: &J, x: u32, y: u32) +where + I: GenericImage, + J: GenericImageView<Pixel = I::Pixel>, +{ + let bottom_dims = bottom.dimensions(); + let top_dims = top.dimensions(); + + // Crop our top image if we're going out of bounds + let (range_width, range_height) = overlay_bounds(bottom_dims, top_dims, x, y); + + for top_y in 0..range_height { + for top_x in 0..range_width { + let p = top.get_pixel(top_x, top_y); + bottom.put_pixel(x + top_x, y + top_y, p); + } + } +} + +#[cfg(test)] +mod tests { + + use super::overlay; + use crate::buffer::ImageBuffer; + use crate::color::Rgb; + + #[test] + /// Test that images written into other images works + fn test_image_in_image() { + let mut target = ImageBuffer::new(32, 32); + let source = ImageBuffer::from_pixel(16, 16, Rgb([255u8, 0, 0])); + overlay(&mut target, &source, 0, 0); + assert!(*target.get_pixel(0, 0) == Rgb([255u8, 0, 0])); + assert!(*target.get_pixel(15, 0) == Rgb([255u8, 0, 0])); + assert!(*target.get_pixel(16, 0) == Rgb([0u8, 0, 0])); + assert!(*target.get_pixel(0, 15) == Rgb([255u8, 0, 0])); + assert!(*target.get_pixel(0, 16) == Rgb([0u8, 0, 0])); + } + + #[test] + /// Test that images written outside of a frame doesn't blow up + fn test_image_in_image_outside_of_bounds() { + let mut target = ImageBuffer::new(32, 32); + let source = ImageBuffer::from_pixel(32, 32, Rgb([255u8, 0, 0])); + overlay(&mut target, &source, 1, 1); + assert!(*target.get_pixel(0, 0) == Rgb([0, 0, 0])); + assert!(*target.get_pixel(1, 1) == Rgb([255u8, 0, 0])); + assert!(*target.get_pixel(31, 31) == Rgb([255u8, 0, 0])); + } + + #[test] + /// Test that images written to coordinates out of the frame doesn't blow up + /// (issue came up in #848) + fn test_image_outside_image_no_wrap_around() { + let mut target = ImageBuffer::new(32, 32); + let source = ImageBuffer::from_pixel(32, 32, Rgb([255u8, 0, 0])); + overlay(&mut target, &source, 33, 33); + assert!(*target.get_pixel(0, 0) == Rgb([0, 0, 0])); + assert!(*target.get_pixel(1, 1) == Rgb([0, 0, 0])); + assert!(*target.get_pixel(31, 31) == Rgb([0, 0, 0])); + } + + #[test] + /// Test that images written to coordinates with overflow works + fn test_image_coordinate_overflow() { + let mut target = ImageBuffer::new(16, 16); + let source = ImageBuffer::from_pixel(32, 32, Rgb([255u8, 0, 0])); + // Overflows to 'sane' coordinates but top is larger than bot. + overlay(&mut target, &source, u32::max_value() - 31, u32::max_value() - 31); + assert!(*target.get_pixel(0, 0) == Rgb([0, 0, 0])); + assert!(*target.get_pixel(1, 1) == Rgb([0, 0, 0])); + assert!(*target.get_pixel(15, 15) == Rgb([0, 0, 0])); + } +} diff --git a/third_party/rust/image/src/imageops/sample.rs b/third_party/rust/image/src/imageops/sample.rs new file mode 100644 index 0000000000..6f8a76da17 --- /dev/null +++ b/third_party/rust/image/src/imageops/sample.rs @@ -0,0 +1,873 @@ +//! Functions and filters for the sampling of pixels. + +// See http://cs.brown.edu/courses/cs123/lectures/08_Image_Processing_IV.pdf +// for some of the theory behind image scaling and convolution + +use std::f32; + +use num_traits::{NumCast, ToPrimitive, Zero}; + +use crate::buffer::{ImageBuffer, Pixel}; +use crate::image::GenericImageView; +use crate::math::utils::clamp; +use crate::traits::{Enlargeable, Primitive}; + +/// Available Sampling Filters. +/// +/// ## Examples +/// +/// To test the different sampling filters on a real example, you can find two +/// examples called +/// [`scaledown`](https://github.com/image-rs/image/tree/master/examples/scaledown) +/// and +/// [`scaleup`](https://github.com/image-rs/image/tree/master/examples/scaleup) +/// in the `examples` directory of the crate source code. +/// +/// Here is a 3.58 MiB +/// [test image](https://github.com/image-rs/image/blob/master/examples/scaledown/test.jpg) +/// that has been scaled down to 300x225 px: +/// +/// <!-- NOTE: To test new test images locally, replace the GitHub path with `../../../docs/` --> +/// <div style="display: flex; flex-wrap: wrap; align-items: flex-start;"> +/// <div style="margin: 0 8px 8px 0;"> +/// <img src="https://raw.githubusercontent.com/image-rs/image/master/examples/scaledown/scaledown-test-near.png" title="Nearest"><br> +/// Nearest Neighbor +/// </div> +/// <div style="margin: 0 8px 8px 0;"> +/// <img src="https://raw.githubusercontent.com/image-rs/image/master/examples/scaledown/scaledown-test-tri.png" title="Triangle"><br> +/// Linear: Triangle +/// </div> +/// <div style="margin: 0 8px 8px 0;"> +/// <img src="https://raw.githubusercontent.com/image-rs/image/master/examples/scaledown/scaledown-test-cmr.png" title="CatmullRom"><br> +/// Cubic: Catmull-Rom +/// </div> +/// <div style="margin: 0 8px 8px 0;"> +/// <img src="https://raw.githubusercontent.com/image-rs/image/master/examples/scaledown/scaledown-test-gauss.png" title="Gaussian"><br> +/// Gaussian +/// </div> +/// <div style="margin: 0 8px 8px 0;"> +/// <img src="https://raw.githubusercontent.com/image-rs/image/master/examples/scaledown/scaledown-test-lcz2.png" title="Lanczos3"><br> +/// Lanczos with window 3 +/// </div> +/// </div> +/// +/// ## Speed +/// +/// Time required to create each of the examples above, tested on an Intel +/// i7-4770 CPU with Rust 1.37 in release mode: +/// +/// <table style="width: auto;"> +/// <tr> +/// <th>Nearest</th> +/// <td>31 ms</td> +/// </tr> +/// <tr> +/// <th>Triangle</th> +/// <td>414 ms</td> +/// </tr> +/// <tr> +/// <th>CatmullRom</th> +/// <td>817 ms</td> +/// </tr> +/// <tr> +/// <th>Gaussian</th> +/// <td>1180 ms</td> +/// </tr> +/// <tr> +/// <th>Lanczos3</th> +/// <td>1170 ms</td> +/// </tr> +/// </table> +#[derive(Clone, Copy, Debug)] +pub enum FilterType { + /// Nearest Neighbor + Nearest, + + /// Linear Filter + Triangle, + + /// Cubic Filter + CatmullRom, + + /// Gaussian Filter + Gaussian, + + /// Lanczos with window 3 + Lanczos3, +} + +/// A Representation of a separable filter. +pub(crate) struct Filter<'a> { + /// The filter's filter function. + pub(crate) kernel: Box<dyn Fn(f32) -> f32 + 'a>, + + /// The window on which this filter operates. + pub(crate) support: f32, +} + +// sinc function: the ideal sampling filter. +fn sinc(t: f32) -> f32 { + let a = t * f32::consts::PI; + + if t == 0.0 { + 1.0 + } else { + a.sin() / a + } +} + +// lanczos kernel function. A windowed sinc function. +fn lanczos(x: f32, t: f32) -> f32 { + if x.abs() < t { + sinc(x) * sinc(x / t) + } else { + 0.0 + } +} + +// Calculate a splice based on the b and c parameters. +// from authors Mitchell and Netravali. +fn bc_cubic_spline(x: f32, b: f32, c: f32) -> f32 { + let a = x.abs(); + + let k = if a < 1.0 { + (12.0 - 9.0 * b - 6.0 * c) * a.powi(3) + (-18.0 + 12.0 * b + 6.0 * c) * a.powi(2) + + (6.0 - 2.0 * b) + } else if a < 2.0 { + (-b - 6.0 * c) * a.powi(3) + (6.0 * b + 30.0 * c) * a.powi(2) + (-12.0 * b - 48.0 * c) * a + + (8.0 * b + 24.0 * c) + } else { + 0.0 + }; + + k / 6.0 +} + +/// The Gaussian Function. +/// ```r``` is the standard deviation. +pub(crate) fn gaussian(x: f32, r: f32) -> f32 { + ((2.0 * f32::consts::PI).sqrt() * r).recip() * (-x.powi(2) / (2.0 * r.powi(2))).exp() +} + +/// Calculate the lanczos kernel with a window of 3 +pub(crate) fn lanczos3_kernel(x: f32) -> f32 { + lanczos(x, 3.0) +} + +/// Calculate the gaussian function with a +/// standard deviation of 0.5 +pub(crate) fn gaussian_kernel(x: f32) -> f32 { + gaussian(x, 0.5) +} + +/// Calculate the Catmull-Rom cubic spline. +/// Also known as a form of `BiCubic` sampling in two dimensions. +pub(crate) fn catmullrom_kernel(x: f32) -> f32 { + bc_cubic_spline(x, 0.0, 0.5) +} + +/// Calculate the triangle function. +/// Also known as `BiLinear` sampling in two dimensions. +pub(crate) fn triangle_kernel(x: f32) -> f32 { + if x.abs() < 1.0 { + 1.0 - x.abs() + } else { + 0.0 + } +} + +/// Calculate the box kernel. +/// Only pixels inside the box should be considered, and those +/// contribute equally. So this method simply returns 1. +pub(crate) fn box_kernel(_x: f32) -> f32 { + 1.0 +} + +// Sample the rows of the supplied image using the provided filter. +// The height of the image remains unchanged. +// ```new_width``` is the desired width of the new image +// ```filter``` is the filter to use for sampling. +fn horizontal_sample<I, P, S>( + image: &I, + new_width: u32, + filter: &mut Filter, +) -> ImageBuffer<P, Vec<S>> +where + I: GenericImageView<Pixel = P>, + P: Pixel<Subpixel = S> + 'static, + S: Primitive + 'static, +{ + let (width, height) = image.dimensions(); + let mut out = ImageBuffer::new(new_width, height); + let mut ws = Vec::new(); + + let max: f32 = NumCast::from(S::max_value()).unwrap(); + let ratio = width as f32 / new_width as f32; + let sratio = if ratio < 1.0 { 1.0 } else { ratio }; + let src_support = filter.support * sratio; + + for outx in 0..new_width { + // Find the point in the input image corresponding to the centre + // of the current pixel in the output image. + let inputx = (outx as f32 + 0.5) * ratio; + + // Left and right are slice bounds for the input pixels relevant + // to the output pixel we are calculating. Pixel x is relevant + // if and only if (x >= left) && (x < right). + + // Invariant: 0 <= left < right <= width + + let left = (inputx - src_support).floor() as i64; + let left = clamp(left, 0, <i64 as From<_>>::from(width) - 1) as u32; + + let right = (inputx + src_support).ceil() as i64; + let right = clamp( + right, + <i64 as From<_>>::from(left) + 1, + <i64 as From<_>>::from(width), + ) as u32; + + // Go back to left boundary of pixel, to properly compare with i + // below, as the kernel treats the centre of a pixel as 0. + let inputx = inputx - 0.5; + + ws.clear(); + let mut sum = 0.0; + for i in left..right { + let w = (filter.kernel)((i as f32 - inputx) / sratio); + ws.push(w); + sum += w; + } + + for y in 0..height { + let mut t = (0.0, 0.0, 0.0, 0.0); + + for (i, w) in ws.iter().enumerate() { + let p = image.get_pixel(left + i as u32, y); + + let (k1, k2, k3, k4) = p.channels4(); + let vec: (f32, f32, f32, f32) = ( + NumCast::from(k1).unwrap(), + NumCast::from(k2).unwrap(), + NumCast::from(k3).unwrap(), + NumCast::from(k4).unwrap(), + ); + + t.0 += vec.0 * w; + t.1 += vec.1 * w; + t.2 += vec.2 * w; + t.3 += vec.3 * w; + } + + let (t1, t2, t3, t4) = (t.0 / sum, t.1 / sum, t.2 / sum, t.3 / sum); + let t = Pixel::from_channels( + NumCast::from(clamp(t1, 0.0, max)).unwrap(), + NumCast::from(clamp(t2, 0.0, max)).unwrap(), + NumCast::from(clamp(t3, 0.0, max)).unwrap(), + NumCast::from(clamp(t4, 0.0, max)).unwrap(), + ); + + out.put_pixel(outx, y, t); + } + } + + out +} + +// Sample the columns of the supplied image using the provided filter. +// The width of the image remains unchanged. +// ```new_height``` is the desired height of the new image +// ```filter``` is the filter to use for sampling. +fn vertical_sample<I, P, S>( + image: &I, + new_height: u32, + filter: &mut Filter, +) -> ImageBuffer<P, Vec<S>> +where + I: GenericImageView<Pixel = P>, + P: Pixel<Subpixel = S> + 'static, + S: Primitive + 'static, +{ + let (width, height) = image.dimensions(); + let mut out = ImageBuffer::new(width, new_height); + let mut ws = Vec::new(); + + let max: f32 = NumCast::from(S::max_value()).unwrap(); + let ratio = height as f32 / new_height as f32; + let sratio = if ratio < 1.0 { 1.0 } else { ratio }; + let src_support = filter.support * sratio; + + for outy in 0..new_height { + // For an explanation of this algorithm, see the comments + // in horizontal_sample. + let inputy = (outy as f32 + 0.5) * ratio; + + let left = (inputy - src_support).floor() as i64; + let left = clamp(left, 0, <i64 as From<_>>::from(height) - 1) as u32; + + let right = (inputy + src_support).ceil() as i64; + let right = clamp( + right, + <i64 as From<_>>::from(left) + 1, + <i64 as From<_>>::from(height), + ) as u32; + + let inputy = inputy - 0.5; + + ws.clear(); + let mut sum = 0.0; + for i in left..right { + let w = (filter.kernel)((i as f32 - inputy) / sratio); + ws.push(w); + sum += w; + } + + for x in 0..width { + let mut t = (0.0, 0.0, 0.0, 0.0); + + for (i, w) in ws.iter().enumerate() { + let p = image.get_pixel(x, left + i as u32); + + let (k1, k2, k3, k4) = p.channels4(); + let vec: (f32, f32, f32, f32) = ( + NumCast::from(k1).unwrap(), + NumCast::from(k2).unwrap(), + NumCast::from(k3).unwrap(), + NumCast::from(k4).unwrap(), + ); + + t.0 += vec.0 * w; + t.1 += vec.1 * w; + t.2 += vec.2 * w; + t.3 += vec.3 * w; + } + + let (t1, t2, t3, t4) = (t.0 / sum, t.1 / sum, t.2 / sum, t.3 / sum); + let t = Pixel::from_channels( + NumCast::from(clamp(t1, 0.0, max)).unwrap(), + NumCast::from(clamp(t2, 0.0, max)).unwrap(), + NumCast::from(clamp(t3, 0.0, max)).unwrap(), + NumCast::from(clamp(t4, 0.0, max)).unwrap(), + ); + + out.put_pixel(x, outy, t); + } + } + + out +} + +/// Local struct for keeping track of pixel sums for fast thumbnail averaging +struct ThumbnailSum<S: Primitive + Enlargeable>(S::Larger, S::Larger, S::Larger, S::Larger); + +impl<S: Primitive + Enlargeable> ThumbnailSum<S> { + fn zeroed() -> Self { + ThumbnailSum(S::Larger::zero(), S::Larger::zero(), S::Larger::zero(), S::Larger::zero()) + } + + fn sample_val(val: S) -> S::Larger { + <S::Larger as NumCast>::from(val).unwrap() + } + + fn add_pixel<P: Pixel<Subpixel=S>>(&mut self, pixel: P) { + let pixel = pixel.channels4(); + self.0 += Self::sample_val(pixel.0); + self.1 += Self::sample_val(pixel.1); + self.2 += Self::sample_val(pixel.2); + self.3 += Self::sample_val(pixel.3); + } +} + +/// Resize the supplied image to the specific dimensions. +/// +/// For downscaling, this method uses a fast integer algorithm where each source pixel contributes +/// to exactly one target pixel. May give aliasing artifacts if new size is close to old size. +/// +/// In case the current width is smaller than the new width or similar for the height, another +/// strategy is used instead. For each pixel in the output, a rectangular region of the input is +/// determined, just as previously. But when no input pixel is part of this region, the nearest +/// pixels are interpolated instead. +/// +/// For speed reasons, all interpolation is performed linearly over the colour values. It will not +/// take the pixel colour spaces into account. +pub fn thumbnail<I, P, S>(image: &I, new_width: u32, new_height: u32) -> ImageBuffer<P, Vec<S>> +where + I: GenericImageView<Pixel = P>, + P: Pixel<Subpixel = S> + 'static, + S: Primitive + Enlargeable + 'static, +{ + let (width, height) = image.dimensions(); + let mut out = ImageBuffer::new(new_width, new_height); + + let x_ratio = width as f32 / new_width as f32; + let y_ratio = height as f32 / new_height as f32; + + for outy in 0..new_height { + let bottomf = outy as f32 * y_ratio; + let topf = bottomf + y_ratio; + + let bottom = clamp( + bottomf.ceil() as u32, + 0, + height - 1, + ); + let top = clamp( + topf.ceil() as u32, + bottom, + height, + ); + + for outx in 0..new_width { + let leftf = outx as f32 * x_ratio; + let rightf = leftf + x_ratio; + + let left = clamp( + leftf.ceil() as u32, + 0, + width - 1, + ); + let right = clamp( + rightf.ceil() as u32, + left, + width, + ); + + let avg = if bottom != top && left != right { + thumbnail_sample_block(image, left, right, bottom, top) + } else if bottom != top { // && left == right + // In the first column we have left == 0 and right > ceil(y_scale) > 0 so this + // assertion can never trigger. + debug_assert!(left > 0 && right > 0, + "First output column must have corresponding pixels"); + + let fraction_horizontal = (leftf.fract() + rightf.fract())/2.; + thumbnail_sample_fraction_horizontal(image, right - 1, fraction_horizontal, bottom, top) + } else if left != right { // && bottom == top + // In the first line we have bottom == 0 and top > ceil(x_scale) > 0 so this + // assertion can never trigger. + debug_assert!(bottom > 0 && top > 0, + "First output row must have corresponding pixels"); + + let fraction_vertical = (topf.fract() + bottomf.fract())/2.; + thumbnail_sample_fraction_vertical(image, left, right, top - 1, fraction_vertical) + } else { // bottom == top && left == right + let fraction_horizontal = (topf.fract() + bottomf.fract())/2.; + let fraction_vertical= (leftf.fract() + rightf.fract())/2.; + + thumbnail_sample_fraction_both(image, right - 1, fraction_horizontal, top - 1, fraction_vertical) + }; + + let pixel = Pixel::from_channels(avg.0, avg.1, avg.2, avg.3); + out.put_pixel(outx, outy, pixel); + } + } + + out +} + +/// Get a pixel for a thumbnail where the input window encloses at least a full pixel. +fn thumbnail_sample_block<I, P, S>( + image: &I, + left: u32, + right: u32, + bottom: u32, + top: u32, +) -> (S, S, S, S) +where + I: GenericImageView<Pixel = P>, + P: Pixel<Subpixel = S>, + S: Primitive + Enlargeable, +{ + let mut sum = ThumbnailSum::zeroed(); + + for y in bottom..top { + for x in left..right { + let k = image.get_pixel(x, y); + sum.add_pixel(k); + } + } + + let n = <S::Larger as NumCast>::from( + (right - left) * (top - bottom)).unwrap(); + let round = <S::Larger as NumCast>::from( + n / NumCast::from(2).unwrap()).unwrap(); + ( + S::clamp_from((sum.0 + round)/n), + S::clamp_from((sum.1 + round)/n), + S::clamp_from((sum.2 + round)/n), + S::clamp_from((sum.3 + round)/n), + ) +} + +/// Get a thumbnail pixel where the input window encloses at least a vertical pixel. +fn thumbnail_sample_fraction_horizontal<I, P, S>( + image: &I, + left: u32, + fraction_horizontal: f32, + bottom: u32, + top: u32, +) -> (S, S, S, S) +where + I: GenericImageView<Pixel = P>, + P: Pixel<Subpixel = S>, + S: Primitive + Enlargeable, +{ + let fract = fraction_horizontal; + + let mut sum_left = ThumbnailSum::zeroed(); + let mut sum_right = ThumbnailSum::zeroed(); + for x in bottom..top { + let k_left = image.get_pixel(left, x); + sum_left.add_pixel(k_left); + + let k_right = image.get_pixel(left + 1, x); + sum_right.add_pixel(k_right); + } + + // Now we approximate: left/n*(1-fract) + right/n*fract + let fact_right = fract /((top - bottom) as f32); + let fact_left = (1. - fract)/((top - bottom) as f32); + + let mix_left_and_right = |leftv: S::Larger, rightv: S::Larger| + <S as NumCast>::from( + fact_left * leftv.to_f32().unwrap() + + fact_right * rightv.to_f32().unwrap() + ).expect("Average sample value should fit into sample type"); + + ( + mix_left_and_right(sum_left.0, sum_right.0), + mix_left_and_right(sum_left.1, sum_right.1), + mix_left_and_right(sum_left.2, sum_right.2), + mix_left_and_right(sum_left.3, sum_right.3), + ) +} + +/// Get a thumbnail pixel where the input window encloses at least a horizontal pixel. +fn thumbnail_sample_fraction_vertical<I, P, S>( + image: &I, + left: u32, + right: u32, + bottom: u32, + fraction_vertical: f32, +) -> (S, S, S, S) +where + I: GenericImageView<Pixel = P>, + P: Pixel<Subpixel = S>, + S: Primitive + Enlargeable, +{ + let fract = fraction_vertical; + + let mut sum_bot = ThumbnailSum::zeroed(); + let mut sum_top = ThumbnailSum::zeroed(); + for x in left..right { + let k_bot = image.get_pixel(x, bottom); + sum_bot.add_pixel(k_bot); + + let k_top = image.get_pixel(x, bottom + 1); + sum_top.add_pixel(k_top); + } + + // Now we approximate: bot/n*fract + top/n*(1-fract) + let fact_top = fract /((right - left) as f32); + let fact_bot = (1. - fract)/((right - left) as f32); + + let mix_bot_and_top = |botv: S::Larger, topv: S::Larger| + <S as NumCast>::from( + fact_bot * botv.to_f32().unwrap() + + fact_top * topv.to_f32().unwrap() + ).expect("Average sample value should fit into sample type"); + + ( + mix_bot_and_top(sum_bot.0, sum_top.0), + mix_bot_and_top(sum_bot.1, sum_top.1), + mix_bot_and_top(sum_bot.2, sum_top.2), + mix_bot_and_top(sum_bot.3, sum_top.3), + ) +} + +/// Get a single pixel for a thumbnail where the input window does not enclose any full pixel. +fn thumbnail_sample_fraction_both<I, P, S>( + image: &I, + left: u32, + fraction_vertical: f32, + bottom: u32, + fraction_horizontal: f32, +) -> (S, S, S, S) +where + I: GenericImageView<Pixel = P>, + P: Pixel<Subpixel = S>, + S: Primitive + Enlargeable, +{ + let k_bl = image.get_pixel(left, bottom ).channels4(); + let k_tl = image.get_pixel(left, bottom + 1).channels4(); + let k_br = image.get_pixel(left + 1, bottom ).channels4(); + let k_tr = image.get_pixel(left + 1, bottom + 1).channels4(); + + let frac_v = fraction_vertical; + let frac_h = fraction_horizontal; + + let fact_tr = frac_v * frac_h; + let fact_tl = frac_v * (1. - frac_h); + let fact_br = (1. - frac_v) * frac_h; + let fact_bl = (1. - frac_v) * (1. - frac_h); + + let mix = |br: S, tr: S, bl: S, tl: S| + <S as NumCast>::from( + fact_br * br.to_f32().unwrap() + + fact_tr * tr.to_f32().unwrap() + + fact_bl * bl.to_f32().unwrap() + + fact_tl * tl.to_f32().unwrap() + ).expect("Average sample value should fit into sample type"); + + ( + mix(k_br.0, k_tr.0, k_bl.0, k_tl.0), + mix(k_br.1, k_tr.1, k_bl.1, k_tl.1), + mix(k_br.2, k_tr.2, k_bl.2, k_tl.2), + mix(k_br.3, k_tr.3, k_bl.3, k_tl.3), + ) +} + +/// Perform a 3x3 box filter on the supplied image. +/// ```kernel``` is an array of the filter weights of length 9. +pub fn filter3x3<I, P, S>(image: &I, kernel: &[f32]) -> ImageBuffer<P, Vec<S>> +where + I: GenericImageView<Pixel = P>, + P: Pixel<Subpixel = S> + 'static, + S: Primitive + 'static, +{ + // The kernel's input positions relative to the current pixel. + let taps: &[(isize, isize)] = &[ + (-1, -1), + (0, -1), + (1, -1), + (-1, 0), + (0, 0), + (1, 0), + (-1, 1), + (0, 1), + (1, 1), + ]; + + let (width, height) = image.dimensions(); + + let mut out = ImageBuffer::new(width, height); + + let max = S::max_value(); + let max: f32 = NumCast::from(max).unwrap(); + + let sum = match kernel.iter().fold(0.0, |s, &item| s + item) { + x if x == 0.0 => 1.0, + sum => sum, + }; + let sum = (sum, sum, sum, sum); + + for y in 1..height - 1 { + for x in 1..width - 1 { + let mut t = (0.0, 0.0, 0.0, 0.0); + + // TODO: There is no need to recalculate the kernel for each pixel. + // Only a subtract and addition is needed for pixels after the first + // in each row. + for (&k, &(a, b)) in kernel.iter().zip(taps.iter()) { + let k = (k, k, k, k); + let x0 = x as isize + a; + let y0 = y as isize + b; + + let p = image.get_pixel(x0 as u32, y0 as u32); + + let (k1, k2, k3, k4) = p.channels4(); + + let vec: (f32, f32, f32, f32) = ( + NumCast::from(k1).unwrap(), + NumCast::from(k2).unwrap(), + NumCast::from(k3).unwrap(), + NumCast::from(k4).unwrap(), + ); + + t.0 += vec.0 * k.0; + t.1 += vec.1 * k.1; + t.2 += vec.2 * k.2; + t.3 += vec.3 * k.3; + } + + let (t1, t2, t3, t4) = (t.0 / sum.0, t.1 / sum.1, t.2 / sum.2, t.3 / sum.3); + + let t = Pixel::from_channels( + NumCast::from(clamp(t1, 0.0, max)).unwrap(), + NumCast::from(clamp(t2, 0.0, max)).unwrap(), + NumCast::from(clamp(t3, 0.0, max)).unwrap(), + NumCast::from(clamp(t4, 0.0, max)).unwrap(), + ); + + out.put_pixel(x, y, t); + } + } + + out +} + +/// Resize the supplied image to the specified dimensions. +/// ```nwidth``` and ```nheight``` are the new dimensions. +/// ```filter``` is the sampling filter to use. +pub fn resize<I: GenericImageView>( + image: &I, + nwidth: u32, + nheight: u32, + filter: FilterType, +) -> ImageBuffer<I::Pixel, Vec<<I::Pixel as Pixel>::Subpixel>> +where + I::Pixel: 'static, + <I::Pixel as Pixel>::Subpixel: 'static, +{ + let mut method = match filter { + FilterType::Nearest => Filter { + kernel: Box::new(box_kernel), + support: 0.0, + }, + FilterType::Triangle => Filter { + kernel: Box::new(triangle_kernel), + support: 1.0, + }, + FilterType::CatmullRom => Filter { + kernel: Box::new(catmullrom_kernel), + support: 2.0, + }, + FilterType::Gaussian => Filter { + kernel: Box::new(gaussian_kernel), + support: 3.0, + }, + FilterType::Lanczos3 => Filter { + kernel: Box::new(lanczos3_kernel), + support: 3.0, + }, + }; + + let tmp = vertical_sample(image, nheight, &mut method); + horizontal_sample(&tmp, nwidth, &mut method) +} + +/// Performs a Gaussian blur on the supplied image. +/// ```sigma``` is a measure of how much to blur by. +pub fn blur<I: GenericImageView>( + image: &I, + sigma: f32, +) -> ImageBuffer<I::Pixel, Vec<<I::Pixel as Pixel>::Subpixel>> +where + I::Pixel: 'static, +{ + let sigma = if sigma < 0.0 { 1.0 } else { sigma }; + + let mut method = Filter { + kernel: Box::new(|x| gaussian(x, sigma)), + support: 2.0 * sigma, + }; + + let (width, height) = image.dimensions(); + + // Keep width and height the same for horizontal and + // vertical sampling. + let tmp = vertical_sample(image, height, &mut method); + horizontal_sample(&tmp, width, &mut method) +} + +/// Performs an unsharpen mask on the supplied image. +/// ```sigma``` is the amount to blur the image by. +/// ```threshold``` is the threshold for the difference between +/// +/// See <https://en.wikipedia.org/wiki/Unsharp_masking#Digital_unsharp_masking> +pub fn unsharpen<I, P, S>(image: &I, sigma: f32, threshold: i32) -> ImageBuffer<P, Vec<S>> +where + I: GenericImageView<Pixel = P>, + P: Pixel<Subpixel = S> + 'static, + S: Primitive + 'static, +{ + let mut tmp = blur(image, sigma); + + let max = S::max_value(); + let max: i32 = NumCast::from(max).unwrap(); + let (width, height) = image.dimensions(); + + for y in 0..height { + for x in 0..width { + let a = image.get_pixel(x, y); + let b = tmp.get_pixel_mut(x, y); + + let p = a.map2(b, |c, d| { + let ic: i32 = NumCast::from(c).unwrap(); + let id: i32 = NumCast::from(d).unwrap(); + + let diff = (ic - id).abs(); + + if diff > threshold { + let e = clamp(ic + diff, 0, max); + + NumCast::from(e).unwrap() + } else { + c + } + }); + + *b = p; + } + } + + tmp +} + +#[cfg(test)] +mod tests { + use super::{resize, FilterType}; + use crate::buffer::{ImageBuffer, RgbImage}; + #[cfg(feature = "benchmarks")] + use test; + + #[bench] + #[cfg(all(feature = "benchmarks", feature = "png"))] + fn bench_resize(b: &mut test::Bencher) { + use std::path::Path; + let img = crate::open(&Path::new("./examples/fractal.png")).unwrap(); + b.iter(|| { + test::black_box(resize(&img, 200, 200, FilterType::Nearest)); + }); + b.bytes = 800 * 800 * 3 + 200 * 200 * 3; + } + + #[test] + fn test_issue_186() { + let img: RgbImage = ImageBuffer::new(100, 100); + let _ = resize(&img, 50, 50, FilterType::Lanczos3); + } + + #[bench] + #[cfg(all(feature = "benchmarks", feature = "tiff"))] + fn bench_thumbnail(b: &mut test::Bencher) { + let path = concat!(env!("CARGO_MANIFEST_DIR"), "/tests/images/tiff/testsuite/mandrill.tiff"); + let image = crate::open(path).unwrap(); + b.iter(|| { + test::black_box(image.thumbnail(256, 256)); + }); + b.bytes = 512 * 512 * 4 + 256 * 256 * 4; + } + + #[bench] + #[cfg(all(feature = "benchmarks", feature = "tiff"))] + fn bench_thumbnail_upsize(b: &mut test::Bencher) { + let path = concat!(env!("CARGO_MANIFEST_DIR"), "/tests/images/tiff/testsuite/mandrill.tiff"); + let image = crate::open(path).unwrap().thumbnail(256, 256); + b.iter(|| { + test::black_box(image.thumbnail(512, 512)); + }); + b.bytes = 512 * 512 * 4 + 256 * 256 * 4; + } + + #[bench] + #[cfg(all(feature = "benchmarks", feature = "tiff"))] + fn bench_thumbnail_upsize_irregular(b: &mut test::Bencher) { + let path = concat!(env!("CARGO_MANIFEST_DIR"), "/tests/images/tiff/testsuite/mandrill.tiff"); + let image = crate::open(path).unwrap().thumbnail(193, 193); + b.iter(|| { + test::black_box(image.thumbnail(256, 256)); + }); + b.bytes = 193 * 193 * 4 + 256 * 256 * 4; + } +} |