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Diffstat (limited to 'vendor/image/src/imageops/sample.rs')
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diff --git a/vendor/image/src/imageops/sample.rs b/vendor/image/src/imageops/sample.rs deleted file mode 100644 index a362f83..0000000 --- a/vendor/image/src/imageops/sample.rs +++ /dev/null @@ -1,1228 +0,0 @@ -//! 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::image::{GenericImage, GenericImageView}; -use crate::traits::{Enlargeable, Pixel, Primitive}; -use crate::utils::clamp; -use crate::{ImageBuffer, Rgba32FImage}; - -/// 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, PartialEq)] -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, -} - -struct FloatNearest(f32); - -// to_i64, to_u64, and to_f64 implicitly affect all other lower conversions. -// Note that to_f64 by default calls to_i64 and thus needs to be overridden. -impl ToPrimitive for FloatNearest { - // to_{i,u}64 is required, to_{i,u}{8,16} are useful. - // If a usecase for full 32 bits is found its trivial to add - fn to_i8(&self) -> Option<i8> { - self.0.round().to_i8() - } - fn to_i16(&self) -> Option<i16> { - self.0.round().to_i16() - } - fn to_i64(&self) -> Option<i64> { - self.0.round().to_i64() - } - fn to_u8(&self) -> Option<u8> { - self.0.round().to_u8() - } - fn to_u16(&self) -> Option<u16> { - self.0.round().to_u16() - } - fn to_u64(&self) -> Option<u64> { - self.0.round().to_u64() - } - fn to_f64(&self) -> Option<f64> { - self.0.to_f64() - } -} - -// 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. -// ```image``` is not necessarily Rgba and the order of channels is passed through. -fn horizontal_sample<P, S>( - image: &Rgba32FImage, - new_width: u32, - filter: &mut Filter, -) -> ImageBuffer<P, Vec<S>> -where - 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::DEFAULT_MAX_VALUE).unwrap(); - let min: f32 = NumCast::from(S::DEFAULT_MIN_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; - } - ws.iter_mut().for_each(|w| *w /= sum); - - 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); - - #[allow(deprecated)] - let vec = p.channels4(); - - t.0 += vec.0 * w; - t.1 += vec.1 * w; - t.2 += vec.2 * w; - t.3 += vec.3 * w; - } - - #[allow(deprecated)] - let t = Pixel::from_channels( - NumCast::from(FloatNearest(clamp(t.0, min, max))).unwrap(), - NumCast::from(FloatNearest(clamp(t.1, min, max))).unwrap(), - NumCast::from(FloatNearest(clamp(t.2, min, max))).unwrap(), - NumCast::from(FloatNearest(clamp(t.3, min, max))).unwrap(), - ); - - out.put_pixel(outx, y, t); - } - } - - out -} - -/// Linearly sample from an image using coordinates in [0, 1]. -pub fn sample_bilinear<P: Pixel>( - img: &impl GenericImageView<Pixel = P>, - u: f32, - v: f32, -) -> Option<P> { - if ![u, v].iter().all(|c| (0.0..=1.0).contains(c)) { - return None; - } - - let (w, h) = img.dimensions(); - if w == 0 || h == 0 { - return None; - } - - let ui = w as f32 * u - 0.5; - let vi = h as f32 * v - 0.5; - interpolate_bilinear( - img, - ui.max(0.).min((w - 1) as f32), - vi.max(0.).min((h - 1) as f32), - ) -} - -/// Sample from an image using coordinates in [0, 1], taking the nearest coordinate. -pub fn sample_nearest<P: Pixel>( - img: &impl GenericImageView<Pixel = P>, - u: f32, - v: f32, -) -> Option<P> { - if ![u, v].iter().all(|c| (0.0..=1.0).contains(c)) { - return None; - } - - let (w, h) = img.dimensions(); - let ui = w as f32 * u - 0.5; - let ui = ui.max(0.).min((w.saturating_sub(1)) as f32); - - let vi = h as f32 * v - 0.5; - let vi = vi.max(0.).min((h.saturating_sub(1)) as f32); - interpolate_nearest(img, ui, vi) -} - -/// Sample from an image using coordinates in [0, w-1] and [0, h-1], taking the -/// nearest pixel. -/// -/// Coordinates outside the image bounds will return `None`, however the -/// behavior for points within half a pixel of the image bounds may change in -/// the future. -pub fn interpolate_nearest<P: Pixel>( - img: &impl GenericImageView<Pixel = P>, - x: f32, - y: f32, -) -> Option<P> { - let (w, h) = img.dimensions(); - if w == 0 || h == 0 { - return None; - } - if !(0.0..=((w - 1) as f32)).contains(&x) { - return None; - } - if !(0.0..=((h - 1) as f32)).contains(&y) { - return None; - } - - Some(img.get_pixel(x.round() as u32, y.round() as u32)) -} - -/// Linearly sample from an image using coordinates in [0, w-1] and [0, h-1]. -pub fn interpolate_bilinear<P: Pixel>( - img: &impl GenericImageView<Pixel = P>, - x: f32, - y: f32, -) -> Option<P> { - let (w, h) = img.dimensions(); - if w == 0 || h == 0 { - return None; - } - if !(0.0..=((w - 1) as f32)).contains(&x) { - return None; - } - if !(0.0..=((h - 1) as f32)).contains(&y) { - return None; - } - - let uf = x.floor(); - let vf = y.floor(); - let uc = (x + 1.).min((w - 1) as f32); - let vc = (y + 1.).min((h - 1) as f32); - - // clamp coords to the range of the image - let coords = [[uf, vf], [uf, vc], [uc, vf], [uc, vc]]; - - assert!(coords - .iter() - .all(|&[u, v]| { img.in_bounds(u as u32, v as u32) })); - let samples = coords.map(|[u, v]| img.get_pixel(u as u32, v as u32)); - assert!(P::CHANNEL_COUNT <= 4); - - // convert samples to f32 - // currently rgba is the largest one, - // so just store as many items as necessary, - // because there's not a simple way to be generic over all of them. - let [sff, sfc, scf, scc] = samples.map(|s| { - let mut out = [0.; 4]; - for (i, c) in s.channels().iter().enumerate() { - out[i] = c.to_f32().unwrap(); - } - out - }); - // weights - let [ufw, vfw] = [x - uf, y - vf]; - let [ucw, vcw] = [1. - ufw, 1. - vfw]; - - // https://en.wikipedia.org/wiki/Bilinear_interpolation#Weighted_mean - // the distance between pixels is 1 so there is no denominator - let wff = ucw * vcw; - let wfc = ucw * vfw; - let wcf = ufw * vcw; - let wcc = ufw * vfw; - assert!(f32::abs((wff + wfc + wcf + wcc) - 1.) < 1e-3); - - // hack to get around not being able to construct a generic Pixel - let mut out = samples[0]; - for (i, c) in out.channels_mut().iter_mut().enumerate() { - let v = wff * sff[i] + wfc * sfc[i] + wcf * scf[i] + wcc * scc[i]; - // this rounding may introduce quantization errors, - // but cannot do anything about it. - *c = <P::Subpixel as NumCast>::from(v.round()).unwrap_or({ - if v < 0.0 { - P::Subpixel::DEFAULT_MIN_VALUE - } else { - P::Subpixel::DEFAULT_MAX_VALUE - } - }) - } - Some(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. -// The return value is not necessarily Rgba, the underlying order of channels in ```image``` is -// preserved. -fn vertical_sample<I, P, S>(image: &I, new_height: u32, filter: &mut Filter) -> Rgba32FImage -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 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; - } - ws.iter_mut().for_each(|w| *w /= sum); - - 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); - - #[allow(deprecated)] - 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; - } - - #[allow(deprecated)] - // This is not necessarily Rgba. - let t = Pixel::from_channels(t.0, t.1, t.2, t.3); - - 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) { - #[allow(deprecated)] - 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, - ) - }; - - #[allow(deprecated)] - 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, -{ - #[allow(deprecated)] - let k_bl = image.get_pixel(left, bottom).channels4(); - #[allow(deprecated)] - let k_tl = image.get_pixel(left, bottom + 1).channels4(); - #[allow(deprecated)] - let k_br = image.get_pixel(left + 1, bottom).channels4(); - #[allow(deprecated)] - 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::DEFAULT_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); - - #[allow(deprecated)] - 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); - - #[allow(deprecated)] - 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, -{ - // check if the new dimensions are the same as the old. if they are, make a copy instead of resampling - if (nwidth, nheight) == image.dimensions() { - let mut tmp = ImageBuffer::new(image.width(), image.height()); - tmp.copy_from(image, 0, 0).unwrap(); - return tmp; - } - - 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, - }, - }; - - // Note: tmp is not necessarily actually Rgba - let tmp: Rgba32FImage = 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. - // Note: tmp is not necessarily actually Rgba - let tmp: Rgba32FImage = 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 minimal brightness change that will be sharpened. -/// -/// 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::DEFAULT_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); // FIXME what does this do for f32? clamp 0-1 integers?? - - NumCast::from(e).unwrap() - } else { - c - } - }); - - *b = p; - } - } - - tmp -} - -#[cfg(test)] -mod tests { - use super::{resize, sample_bilinear, sample_nearest, FilterType}; - use crate::{GenericImageView, 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] - #[cfg(feature = "png")] - fn test_resize_same_size() { - use std::path::Path; - let img = crate::open(&Path::new("./examples/fractal.png")).unwrap(); - let resize = img.resize(img.width(), img.height(), FilterType::Triangle); - assert!(img.pixels().eq(resize.pixels())) - } - - #[test] - #[cfg(feature = "png")] - fn test_sample_bilinear() { - use std::path::Path; - let img = crate::open(&Path::new("./examples/fractal.png")).unwrap(); - assert!(sample_bilinear(&img, 0., 0.).is_some()); - assert!(sample_bilinear(&img, 1., 0.).is_some()); - assert!(sample_bilinear(&img, 0., 1.).is_some()); - assert!(sample_bilinear(&img, 1., 1.).is_some()); - assert!(sample_bilinear(&img, 0.5, 0.5).is_some()); - - assert!(sample_bilinear(&img, 1.2, 0.5).is_none()); - assert!(sample_bilinear(&img, 0.5, 1.2).is_none()); - assert!(sample_bilinear(&img, 1.2, 1.2).is_none()); - - assert!(sample_bilinear(&img, -0.1, 0.2).is_none()); - assert!(sample_bilinear(&img, 0.2, -0.1).is_none()); - assert!(sample_bilinear(&img, -0.1, -0.1).is_none()); - } - #[test] - #[cfg(feature = "png")] - fn test_sample_nearest() { - use std::path::Path; - let img = crate::open(&Path::new("./examples/fractal.png")).unwrap(); - assert!(sample_nearest(&img, 0., 0.).is_some()); - assert!(sample_nearest(&img, 1., 0.).is_some()); - assert!(sample_nearest(&img, 0., 1.).is_some()); - assert!(sample_nearest(&img, 1., 1.).is_some()); - assert!(sample_nearest(&img, 0.5, 0.5).is_some()); - - assert!(sample_nearest(&img, 1.2, 0.5).is_none()); - assert!(sample_nearest(&img, 0.5, 1.2).is_none()); - assert!(sample_nearest(&img, 1.2, 1.2).is_none()); - - assert!(sample_nearest(&img, -0.1, 0.2).is_none()); - assert!(sample_nearest(&img, 0.2, -0.1).is_none()); - assert!(sample_nearest(&img, -0.1, -0.1).is_none()); - } - #[test] - fn test_sample_bilinear_correctness() { - use crate::Rgba; - let img = ImageBuffer::from_fn(2, 2, |x, y| match (x, y) { - (0, 0) => Rgba([255, 0, 0, 0]), - (0, 1) => Rgba([0, 255, 0, 0]), - (1, 0) => Rgba([0, 0, 255, 0]), - (1, 1) => Rgba([0, 0, 0, 255]), - _ => panic!(), - }); - assert_eq!(sample_bilinear(&img, 0.5, 0.5), Some(Rgba([64; 4]))); - assert_eq!(sample_bilinear(&img, 0.0, 0.0), Some(Rgba([255, 0, 0, 0]))); - assert_eq!(sample_bilinear(&img, 0.0, 1.0), Some(Rgba([0, 255, 0, 0]))); - assert_eq!(sample_bilinear(&img, 1.0, 0.0), Some(Rgba([0, 0, 255, 0]))); - assert_eq!(sample_bilinear(&img, 1.0, 1.0), Some(Rgba([0, 0, 0, 255]))); - - assert_eq!( - sample_bilinear(&img, 0.5, 0.0), - Some(Rgba([128, 0, 128, 0])) - ); - assert_eq!( - sample_bilinear(&img, 0.0, 0.5), - Some(Rgba([128, 128, 0, 0])) - ); - assert_eq!( - sample_bilinear(&img, 0.5, 1.0), - Some(Rgba([0, 128, 0, 128])) - ); - assert_eq!( - sample_bilinear(&img, 1.0, 0.5), - Some(Rgba([0, 0, 128, 128])) - ); - } - #[test] - fn test_sample_nearest_correctness() { - use crate::Rgba; - let img = ImageBuffer::from_fn(2, 2, |x, y| match (x, y) { - (0, 0) => Rgba([255, 0, 0, 0]), - (0, 1) => Rgba([0, 255, 0, 0]), - (1, 0) => Rgba([0, 0, 255, 0]), - (1, 1) => Rgba([0, 0, 0, 255]), - _ => panic!(), - }); - - assert_eq!(sample_nearest(&img, 0.0, 0.0), Some(Rgba([255, 0, 0, 0]))); - assert_eq!(sample_nearest(&img, 0.0, 1.0), Some(Rgba([0, 255, 0, 0]))); - assert_eq!(sample_nearest(&img, 1.0, 0.0), Some(Rgba([0, 0, 255, 0]))); - assert_eq!(sample_nearest(&img, 1.0, 1.0), Some(Rgba([0, 0, 0, 255]))); - - assert_eq!(sample_nearest(&img, 0.5, 0.5), Some(Rgba([0, 0, 0, 255]))); - assert_eq!(sample_nearest(&img, 0.5, 0.0), Some(Rgba([0, 0, 255, 0]))); - assert_eq!(sample_nearest(&img, 0.0, 0.5), Some(Rgba([0, 255, 0, 0]))); - assert_eq!(sample_nearest(&img, 0.5, 1.0), Some(Rgba([0, 0, 0, 255]))); - assert_eq!(sample_nearest(&img, 1.0, 0.5), Some(Rgba([0, 0, 0, 255]))); - } - - #[bench] - #[cfg(all(feature = "benchmarks", feature = "tiff"))] - fn bench_resize_same_size(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.resize(image.width(), image.height(), FilterType::CatmullRom)); - }); - b.bytes = (image.width() * image.height() * 3) as u64; - } - - #[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; - } - - #[test] - #[cfg(feature = "png")] - fn resize_transparent_image() { - use super::FilterType::{CatmullRom, Gaussian, Lanczos3, Nearest, Triangle}; - use crate::imageops::crop_imm; - use crate::RgbaImage; - - fn assert_resize(image: &RgbaImage, filter: FilterType) { - let resized = resize(image, 16, 16, filter); - let cropped = crop_imm(&resized, 5, 5, 6, 6).to_image(); - for pixel in cropped.pixels() { - let alpha = pixel.0[3]; - assert!( - alpha != 254 && alpha != 253, - "alpha value: {}, {:?}", - alpha, - filter - ); - } - } - - let path = concat!( - env!("CARGO_MANIFEST_DIR"), - "/tests/images/png/transparency/tp1n3p08.png" - ); - let img = crate::open(path).unwrap(); - let rgba8 = img.as_rgba8().unwrap(); - let filters = &[Nearest, Triangle, CatmullRom, Gaussian, Lanczos3]; - for filter in filters { - assert_resize(rgba8, *filter); - } - } - - #[test] - fn bug_1600() { - let image = crate::RgbaImage::from_raw(629, 627, vec![255; 629 * 627 * 4]).unwrap(); - let result = resize(&image, 22, 22, FilterType::Lanczos3); - assert!(result.into_raw().into_iter().any(|c| c != 0)); - } -} |