| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/image-0.23.14/./src/imageops/sample.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>sample.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../normalize.css"><link rel="stylesheet" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../ayu.css" disabled><link rel="stylesheet" href="../../../dark.css" disabled><link rel="stylesheet" href="../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../storage.js"></script><script defer src="../../../source-script.js"></script><script defer src="../../../source-files.js"></script><script defer src="../../../main.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../../image/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../image/index.html"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="doccomment">//! Functions and filters for the sampling of pixels. |
| |
| </span><span class="comment">// See http://cs.brown.edu/courses/cs123/lectures/08_Image_Processing_IV.pdf |
| // for some of the theory behind image scaling and convolution |
| |
| </span><span class="kw">use </span>std::f32; |
| |
| <span class="kw">use </span>num_traits::{NumCast, ToPrimitive, Zero}; |
| |
| <span class="kw">use </span><span class="kw">crate</span>::ImageBuffer; |
| <span class="kw">use </span><span class="kw">crate</span>::image::GenericImageView; |
| <span class="kw">use </span><span class="kw">crate</span>::utils::clamp; |
| <span class="kw">use </span><span class="kw">crate</span>::traits::{Enlargeable, Pixel, Primitive}; |
| |
| <span class="doccomment">/// 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> |
| </span><span class="attribute">#[derive(Clone, Copy, Debug, PartialEq)] |
| </span><span class="kw">pub enum </span>FilterType { |
| <span class="doccomment">/// Nearest Neighbor |
| </span>Nearest, |
| |
| <span class="doccomment">/// Linear Filter |
| </span>Triangle, |
| |
| <span class="doccomment">/// Cubic Filter |
| </span>CatmullRom, |
| |
| <span class="doccomment">/// Gaussian Filter |
| </span>Gaussian, |
| |
| <span class="doccomment">/// Lanczos with window 3 |
| </span>Lanczos3, |
| } |
| |
| <span class="doccomment">/// A Representation of a separable filter. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>Filter<<span class="lifetime">'a</span>> { |
| <span class="doccomment">/// The filter's filter function. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) kernel: Box<<span class="kw">dyn </span>Fn(f32) -> f32 + <span class="lifetime">'a</span>>, |
| |
| <span class="doccomment">/// The window on which this filter operates. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) support: f32, |
| } |
| |
| <span class="kw">struct </span>FloatNearest(f32); |
| |
| <span class="comment">// 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. |
| </span><span class="kw">impl </span>ToPrimitive <span class="kw">for </span>FloatNearest { |
| <span class="kw">fn </span>to_i64(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><i64> { |
| NumCast::from(<span class="self">self</span>.<span class="number">0</span>.round()) |
| } |
| <span class="kw">fn </span>to_u64(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><u64> { |
| NumCast::from(<span class="self">self</span>.<span class="number">0</span>.round()) |
| } |
| <span class="kw">fn </span>to_f64(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><f64> { |
| NumCast::from(<span class="self">self</span>.<span class="number">0</span>) |
| } |
| } |
| |
| <span class="comment">// sinc function: the ideal sampling filter. |
| </span><span class="kw">fn </span>sinc(t: f32) -> f32 { |
| <span class="kw">let </span>a = t * f32::consts::PI; |
| |
| <span class="kw">if </span>t == <span class="number">0.0 </span>{ |
| <span class="number">1.0 |
| </span>} <span class="kw">else </span>{ |
| a.sin() / a |
| } |
| } |
| |
| <span class="comment">// lanczos kernel function. A windowed sinc function. |
| </span><span class="kw">fn </span>lanczos(x: f32, t: f32) -> f32 { |
| <span class="kw">if </span>x.abs() < t { |
| sinc(x) * sinc(x / t) |
| } <span class="kw">else </span>{ |
| <span class="number">0.0 |
| </span>} |
| } |
| |
| <span class="comment">// Calculate a splice based on the b and c parameters. |
| // from authors Mitchell and Netravali. |
| </span><span class="kw">fn </span>bc_cubic_spline(x: f32, b: f32, c: f32) -> f32 { |
| <span class="kw">let </span>a = x.abs(); |
| |
| <span class="kw">let </span>k = <span class="kw">if </span>a < <span class="number">1.0 </span>{ |
| (<span class="number">12.0 </span>- <span class="number">9.0 </span>* b - <span class="number">6.0 </span>* c) * a.powi(<span class="number">3</span>) + (-<span class="number">18.0 </span>+ <span class="number">12.0 </span>* b + <span class="number">6.0 </span>* c) * a.powi(<span class="number">2</span>) |
| + (<span class="number">6.0 </span>- <span class="number">2.0 </span>* b) |
| } <span class="kw">else if </span>a < <span class="number">2.0 </span>{ |
| (-b - <span class="number">6.0 </span>* c) * a.powi(<span class="number">3</span>) + (<span class="number">6.0 </span>* b + <span class="number">30.0 </span>* c) * a.powi(<span class="number">2</span>) + (-<span class="number">12.0 </span>* b - <span class="number">48.0 </span>* c) * a |
| + (<span class="number">8.0 </span>* b + <span class="number">24.0 </span>* c) |
| } <span class="kw">else </span>{ |
| <span class="number">0.0 |
| </span>}; |
| |
| k / <span class="number">6.0 |
| </span>} |
| |
| <span class="doccomment">/// The Gaussian Function. |
| /// ```r``` is the standard deviation. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>gaussian(x: f32, r: f32) -> f32 { |
| ((<span class="number">2.0 </span>* f32::consts::PI).sqrt() * r).recip() * (-x.powi(<span class="number">2</span>) / (<span class="number">2.0 </span>* r.powi(<span class="number">2</span>))).exp() |
| } |
| |
| <span class="doccomment">/// Calculate the lanczos kernel with a window of 3 |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>lanczos3_kernel(x: f32) -> f32 { |
| lanczos(x, <span class="number">3.0</span>) |
| } |
| |
| <span class="doccomment">/// Calculate the gaussian function with a |
| /// standard deviation of 0.5 |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>gaussian_kernel(x: f32) -> f32 { |
| gaussian(x, <span class="number">0.5</span>) |
| } |
| |
| <span class="doccomment">/// Calculate the Catmull-Rom cubic spline. |
| /// Also known as a form of `BiCubic` sampling in two dimensions. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>catmullrom_kernel(x: f32) -> f32 { |
| bc_cubic_spline(x, <span class="number">0.0</span>, <span class="number">0.5</span>) |
| } |
| |
| <span class="doccomment">/// Calculate the triangle function. |
| /// Also known as `BiLinear` sampling in two dimensions. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>triangle_kernel(x: f32) -> f32 { |
| <span class="kw">if </span>x.abs() < <span class="number">1.0 </span>{ |
| <span class="number">1.0 </span>- x.abs() |
| } <span class="kw">else </span>{ |
| <span class="number">0.0 |
| </span>} |
| } |
| |
| <span class="doccomment">/// Calculate the box kernel. |
| /// Only pixels inside the box should be considered, and those |
| /// contribute equally. So this method simply returns 1. |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>box_kernel(_x: f32) -> f32 { |
| <span class="number">1.0 |
| </span>} |
| |
| <span class="comment">// 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. |
| </span><span class="kw">fn </span>horizontal_sample<I, P, S>( |
| image: <span class="kw-2">&</span>I, |
| new_width: u32, |
| filter: <span class="kw-2">&mut </span>Filter, |
| ) -> ImageBuffer<P, Vec<S>> |
| <span class="kw">where |
| </span>I: GenericImageView<Pixel = P>, |
| P: Pixel<Subpixel = S> + <span class="lifetime">'static</span>, |
| S: Primitive + <span class="lifetime">'static</span>, |
| { |
| <span class="kw">let </span>(width, height) = image.dimensions(); |
| <span class="kw">let </span><span class="kw-2">mut </span>out = ImageBuffer::new(new_width, height); |
| <span class="kw">let </span><span class="kw-2">mut </span>ws = Vec::new(); |
| |
| <span class="kw">let </span>max: f32 = NumCast::from(S::max_value()).unwrap(); |
| <span class="kw">let </span>ratio = width <span class="kw">as </span>f32 / new_width <span class="kw">as </span>f32; |
| <span class="kw">let </span>sratio = <span class="kw">if </span>ratio < <span class="number">1.0 </span>{ <span class="number">1.0 </span>} <span class="kw">else </span>{ ratio }; |
| <span class="kw">let </span>src_support = filter.support * sratio; |
| |
| <span class="kw">for </span>outx <span class="kw">in </span><span class="number">0</span>..new_width { |
| <span class="comment">// Find the point in the input image corresponding to the centre |
| // of the current pixel in the output image. |
| </span><span class="kw">let </span>inputx = (outx <span class="kw">as </span>f32 + <span class="number">0.5</span>) * ratio; |
| |
| <span class="comment">// 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 |
| |
| </span><span class="kw">let </span>left = (inputx - src_support).floor() <span class="kw">as </span>i64; |
| <span class="kw">let </span>left = clamp(left, <span class="number">0</span>, <i64 <span class="kw">as </span>From<<span class="kw">_</span>>>::from(width) - <span class="number">1</span>) <span class="kw">as </span>u32; |
| |
| <span class="kw">let </span>right = (inputx + src_support).ceil() <span class="kw">as </span>i64; |
| <span class="kw">let </span>right = clamp( |
| right, |
| <i64 <span class="kw">as </span>From<<span class="kw">_</span>>>::from(left) + <span class="number">1</span>, |
| <i64 <span class="kw">as </span>From<<span class="kw">_</span>>>::from(width), |
| ) <span class="kw">as </span>u32; |
| |
| <span class="comment">// Go back to left boundary of pixel, to properly compare with i |
| // below, as the kernel treats the centre of a pixel as 0. |
| </span><span class="kw">let </span>inputx = inputx - <span class="number">0.5</span>; |
| |
| ws.clear(); |
| <span class="kw">let </span><span class="kw-2">mut </span>sum = <span class="number">0.0</span>; |
| <span class="kw">for </span>i <span class="kw">in </span>left..right { |
| <span class="kw">let </span>w = (filter.kernel)((i <span class="kw">as </span>f32 - inputx) / sratio); |
| ws.push(w); |
| sum += w; |
| } |
| |
| <span class="kw">for </span>y <span class="kw">in </span><span class="number">0</span>..height { |
| <span class="kw">let </span><span class="kw-2">mut </span>t = (<span class="number">0.0</span>, <span class="number">0.0</span>, <span class="number">0.0</span>, <span class="number">0.0</span>); |
| |
| <span class="kw">for </span>(i, w) <span class="kw">in </span>ws.iter().enumerate() { |
| <span class="kw">let </span>p = image.get_pixel(left + i <span class="kw">as </span>u32, y); |
| |
| <span class="kw">let </span>(k1, k2, k3, k4) = p.channels4(); |
| <span class="kw">let </span>vec: (f32, f32, f32, f32) = ( |
| NumCast::from(k1).unwrap(), |
| NumCast::from(k2).unwrap(), |
| NumCast::from(k3).unwrap(), |
| NumCast::from(k4).unwrap(), |
| ); |
| |
| t.<span class="number">0 </span>+= vec.<span class="number">0 </span>* w; |
| t.<span class="number">1 </span>+= vec.<span class="number">1 </span>* w; |
| t.<span class="number">2 </span>+= vec.<span class="number">2 </span>* w; |
| t.<span class="number">3 </span>+= vec.<span class="number">3 </span>* w; |
| } |
| |
| <span class="kw">let </span>(t1, t2, t3, t4) = (t.<span class="number">0 </span>/ sum, t.<span class="number">1 </span>/ sum, t.<span class="number">2 </span>/ sum, t.<span class="number">3 </span>/ sum); |
| <span class="kw">let </span>t = Pixel::from_channels( |
| NumCast::from(FloatNearest(clamp(t1, <span class="number">0.0</span>, max))).unwrap(), |
| NumCast::from(FloatNearest(clamp(t2, <span class="number">0.0</span>, max))).unwrap(), |
| NumCast::from(FloatNearest(clamp(t3, <span class="number">0.0</span>, max))).unwrap(), |
| NumCast::from(FloatNearest(clamp(t4, <span class="number">0.0</span>, max))).unwrap(), |
| ); |
| |
| out.put_pixel(outx, y, t); |
| } |
| } |
| |
| out |
| } |
| |
| <span class="comment">// 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. |
| </span><span class="kw">fn </span>vertical_sample<I, P, S>( |
| image: <span class="kw-2">&</span>I, |
| new_height: u32, |
| filter: <span class="kw-2">&mut </span>Filter, |
| ) -> ImageBuffer<P, Vec<S>> |
| <span class="kw">where |
| </span>I: GenericImageView<Pixel = P>, |
| P: Pixel<Subpixel = S> + <span class="lifetime">'static</span>, |
| S: Primitive + <span class="lifetime">'static</span>, |
| { |
| <span class="kw">let </span>(width, height) = image.dimensions(); |
| <span class="kw">let </span><span class="kw-2">mut </span>out = ImageBuffer::new(width, new_height); |
| <span class="kw">let </span><span class="kw-2">mut </span>ws = Vec::new(); |
| |
| <span class="kw">let </span>max: f32 = NumCast::from(S::max_value()).unwrap(); |
| <span class="kw">let </span>ratio = height <span class="kw">as </span>f32 / new_height <span class="kw">as </span>f32; |
| <span class="kw">let </span>sratio = <span class="kw">if </span>ratio < <span class="number">1.0 </span>{ <span class="number">1.0 </span>} <span class="kw">else </span>{ ratio }; |
| <span class="kw">let </span>src_support = filter.support * sratio; |
| |
| <span class="kw">for </span>outy <span class="kw">in </span><span class="number">0</span>..new_height { |
| <span class="comment">// For an explanation of this algorithm, see the comments |
| // in horizontal_sample. |
| </span><span class="kw">let </span>inputy = (outy <span class="kw">as </span>f32 + <span class="number">0.5</span>) * ratio; |
| |
| <span class="kw">let </span>left = (inputy - src_support).floor() <span class="kw">as </span>i64; |
| <span class="kw">let </span>left = clamp(left, <span class="number">0</span>, <i64 <span class="kw">as </span>From<<span class="kw">_</span>>>::from(height) - <span class="number">1</span>) <span class="kw">as </span>u32; |
| |
| <span class="kw">let </span>right = (inputy + src_support).ceil() <span class="kw">as </span>i64; |
| <span class="kw">let </span>right = clamp( |
| right, |
| <i64 <span class="kw">as </span>From<<span class="kw">_</span>>>::from(left) + <span class="number">1</span>, |
| <i64 <span class="kw">as </span>From<<span class="kw">_</span>>>::from(height), |
| ) <span class="kw">as </span>u32; |
| |
| <span class="kw">let </span>inputy = inputy - <span class="number">0.5</span>; |
| |
| ws.clear(); |
| <span class="kw">let </span><span class="kw-2">mut </span>sum = <span class="number">0.0</span>; |
| <span class="kw">for </span>i <span class="kw">in </span>left..right { |
| <span class="kw">let </span>w = (filter.kernel)((i <span class="kw">as </span>f32 - inputy) / sratio); |
| ws.push(w); |
| sum += w; |
| } |
| |
| <span class="kw">for </span>x <span class="kw">in </span><span class="number">0</span>..width { |
| <span class="kw">let </span><span class="kw-2">mut </span>t = (<span class="number">0.0</span>, <span class="number">0.0</span>, <span class="number">0.0</span>, <span class="number">0.0</span>); |
| |
| <span class="kw">for </span>(i, w) <span class="kw">in </span>ws.iter().enumerate() { |
| <span class="kw">let </span>p = image.get_pixel(x, left + i <span class="kw">as </span>u32); |
| |
| <span class="kw">let </span>(k1, k2, k3, k4) = p.channels4(); |
| <span class="kw">let </span>vec: (f32, f32, f32, f32) = ( |
| NumCast::from(k1).unwrap(), |
| NumCast::from(k2).unwrap(), |
| NumCast::from(k3).unwrap(), |
| NumCast::from(k4).unwrap(), |
| ); |
| |
| t.<span class="number">0 </span>+= vec.<span class="number">0 </span>* w; |
| t.<span class="number">1 </span>+= vec.<span class="number">1 </span>* w; |
| t.<span class="number">2 </span>+= vec.<span class="number">2 </span>* w; |
| t.<span class="number">3 </span>+= vec.<span class="number">3 </span>* w; |
| } |
| |
| <span class="kw">let </span>(t1, t2, t3, t4) = (t.<span class="number">0 </span>/ sum, t.<span class="number">1 </span>/ sum, t.<span class="number">2 </span>/ sum, t.<span class="number">3 </span>/ sum); |
| <span class="kw">let </span>t = Pixel::from_channels( |
| NumCast::from(FloatNearest(clamp(t1, <span class="number">0.0</span>, max))).unwrap(), |
| NumCast::from(FloatNearest(clamp(t2, <span class="number">0.0</span>, max))).unwrap(), |
| NumCast::from(FloatNearest(clamp(t3, <span class="number">0.0</span>, max))).unwrap(), |
| NumCast::from(FloatNearest(clamp(t4, <span class="number">0.0</span>, max))).unwrap(), |
| ); |
| |
| out.put_pixel(x, outy, t); |
| } |
| } |
| |
| out |
| } |
| |
| <span class="doccomment">/// Local struct for keeping track of pixel sums for fast thumbnail averaging |
| </span><span class="kw">struct </span>ThumbnailSum<S: Primitive + Enlargeable>(S::Larger, S::Larger, S::Larger, S::Larger); |
| |
| <span class="kw">impl</span><S: Primitive + Enlargeable> ThumbnailSum<S> { |
| <span class="kw">fn </span>zeroed() -> <span class="self">Self </span>{ |
| ThumbnailSum(S::Larger::zero(), S::Larger::zero(), S::Larger::zero(), S::Larger::zero()) |
| } |
| |
| <span class="kw">fn </span>sample_val(val: S) -> S::Larger { |
| <S::Larger <span class="kw">as </span>NumCast>::from(val).unwrap() |
| } |
| |
| <span class="kw">fn </span>add_pixel<P: Pixel<Subpixel=S>>(<span class="kw-2">&mut </span><span class="self">self</span>, pixel: P) { |
| <span class="kw">let </span>pixel = pixel.channels4(); |
| <span class="self">self</span>.<span class="number">0 </span>+= <span class="self">Self</span>::sample_val(pixel.<span class="number">0</span>); |
| <span class="self">self</span>.<span class="number">1 </span>+= <span class="self">Self</span>::sample_val(pixel.<span class="number">1</span>); |
| <span class="self">self</span>.<span class="number">2 </span>+= <span class="self">Self</span>::sample_val(pixel.<span class="number">2</span>); |
| <span class="self">self</span>.<span class="number">3 </span>+= <span class="self">Self</span>::sample_val(pixel.<span class="number">3</span>); |
| } |
| } |
| |
| <span class="doccomment">/// 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. |
| </span><span class="kw">pub fn </span>thumbnail<I, P, S>(image: <span class="kw-2">&</span>I, new_width: u32, new_height: u32) -> ImageBuffer<P, Vec<S>> |
| <span class="kw">where |
| </span>I: GenericImageView<Pixel = P>, |
| P: Pixel<Subpixel = S> + <span class="lifetime">'static</span>, |
| S: Primitive + Enlargeable + <span class="lifetime">'static</span>, |
| { |
| <span class="kw">let </span>(width, height) = image.dimensions(); |
| <span class="kw">let </span><span class="kw-2">mut </span>out = ImageBuffer::new(new_width, new_height); |
| |
| <span class="kw">let </span>x_ratio = width <span class="kw">as </span>f32 / new_width <span class="kw">as </span>f32; |
| <span class="kw">let </span>y_ratio = height <span class="kw">as </span>f32 / new_height <span class="kw">as </span>f32; |
| |
| <span class="kw">for </span>outy <span class="kw">in </span><span class="number">0</span>..new_height { |
| <span class="kw">let </span>bottomf = outy <span class="kw">as </span>f32 * y_ratio; |
| <span class="kw">let </span>topf = bottomf + y_ratio; |
| |
| <span class="kw">let </span>bottom = clamp( |
| bottomf.ceil() <span class="kw">as </span>u32, |
| <span class="number">0</span>, |
| height - <span class="number">1</span>, |
| ); |
| <span class="kw">let </span>top = clamp( |
| topf.ceil() <span class="kw">as </span>u32, |
| bottom, |
| height, |
| ); |
| |
| <span class="kw">for </span>outx <span class="kw">in </span><span class="number">0</span>..new_width { |
| <span class="kw">let </span>leftf = outx <span class="kw">as </span>f32 * x_ratio; |
| <span class="kw">let </span>rightf = leftf + x_ratio; |
| |
| <span class="kw">let </span>left = clamp( |
| leftf.ceil() <span class="kw">as </span>u32, |
| <span class="number">0</span>, |
| width - <span class="number">1</span>, |
| ); |
| <span class="kw">let </span>right = clamp( |
| rightf.ceil() <span class="kw">as </span>u32, |
| left, |
| width, |
| ); |
| |
| <span class="kw">let </span>avg = <span class="kw">if </span>bottom != top && left != right { |
| thumbnail_sample_block(image, left, right, bottom, top) |
| } <span class="kw">else if </span>bottom != top { <span class="comment">// && left == right |
| // In the first column we have left == 0 and right > ceil(y_scale) > 0 so this |
| // assertion can never trigger. |
| </span><span class="macro">debug_assert!</span>(left > <span class="number">0 </span>&& right > <span class="number">0</span>, |
| <span class="string">"First output column must have corresponding pixels"</span>); |
| |
| <span class="kw">let </span>fraction_horizontal = (leftf.fract() + rightf.fract())/<span class="number">2.</span>; |
| thumbnail_sample_fraction_horizontal(image, right - <span class="number">1</span>, fraction_horizontal, bottom, top) |
| } <span class="kw">else if </span>left != right { <span class="comment">// && bottom == top |
| // In the first line we have bottom == 0 and top > ceil(x_scale) > 0 so this |
| // assertion can never trigger. |
| </span><span class="macro">debug_assert!</span>(bottom > <span class="number">0 </span>&& top > <span class="number">0</span>, |
| <span class="string">"First output row must have corresponding pixels"</span>); |
| |
| <span class="kw">let </span>fraction_vertical = (topf.fract() + bottomf.fract())/<span class="number">2.</span>; |
| thumbnail_sample_fraction_vertical(image, left, right, top - <span class="number">1</span>, fraction_vertical) |
| } <span class="kw">else </span>{ <span class="comment">// bottom == top && left == right |
| </span><span class="kw">let </span>fraction_horizontal = (topf.fract() + bottomf.fract())/<span class="number">2.</span>; |
| <span class="kw">let </span>fraction_vertical= (leftf.fract() + rightf.fract())/<span class="number">2.</span>; |
| |
| thumbnail_sample_fraction_both(image, right - <span class="number">1</span>, fraction_horizontal, top - <span class="number">1</span>, fraction_vertical) |
| }; |
| |
| <span class="kw">let </span>pixel = Pixel::from_channels(avg.<span class="number">0</span>, avg.<span class="number">1</span>, avg.<span class="number">2</span>, avg.<span class="number">3</span>); |
| out.put_pixel(outx, outy, pixel); |
| } |
| } |
| |
| out |
| } |
| |
| <span class="doccomment">/// Get a pixel for a thumbnail where the input window encloses at least a full pixel. |
| </span><span class="kw">fn </span>thumbnail_sample_block<I, P, S>( |
| image: <span class="kw-2">&</span>I, |
| left: u32, |
| right: u32, |
| bottom: u32, |
| top: u32, |
| ) -> (S, S, S, S) |
| <span class="kw">where |
| </span>I: GenericImageView<Pixel = P>, |
| P: Pixel<Subpixel = S>, |
| S: Primitive + Enlargeable, |
| { |
| <span class="kw">let </span><span class="kw-2">mut </span>sum = ThumbnailSum::zeroed(); |
| |
| <span class="kw">for </span>y <span class="kw">in </span>bottom..top { |
| <span class="kw">for </span>x <span class="kw">in </span>left..right { |
| <span class="kw">let </span>k = image.get_pixel(x, y); |
| sum.add_pixel(k); |
| } |
| } |
| |
| <span class="kw">let </span>n = <S::Larger <span class="kw">as </span>NumCast>::from( |
| (right - left) * (top - bottom)).unwrap(); |
| <span class="kw">let </span>round = <S::Larger <span class="kw">as </span>NumCast>::from( |
| n / NumCast::from(<span class="number">2</span>).unwrap()).unwrap(); |
| ( |
| S::clamp_from((sum.<span class="number">0 </span>+ round)/n), |
| S::clamp_from((sum.<span class="number">1 </span>+ round)/n), |
| S::clamp_from((sum.<span class="number">2 </span>+ round)/n), |
| S::clamp_from((sum.<span class="number">3 </span>+ round)/n), |
| ) |
| } |
| |
| <span class="doccomment">/// Get a thumbnail pixel where the input window encloses at least a vertical pixel. |
| </span><span class="kw">fn </span>thumbnail_sample_fraction_horizontal<I, P, S>( |
| image: <span class="kw-2">&</span>I, |
| left: u32, |
| fraction_horizontal: f32, |
| bottom: u32, |
| top: u32, |
| ) -> (S, S, S, S) |
| <span class="kw">where |
| </span>I: GenericImageView<Pixel = P>, |
| P: Pixel<Subpixel = S>, |
| S: Primitive + Enlargeable, |
| { |
| <span class="kw">let </span>fract = fraction_horizontal; |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>sum_left = ThumbnailSum::zeroed(); |
| <span class="kw">let </span><span class="kw-2">mut </span>sum_right = ThumbnailSum::zeroed(); |
| <span class="kw">for </span>x <span class="kw">in </span>bottom..top { |
| <span class="kw">let </span>k_left = image.get_pixel(left, x); |
| sum_left.add_pixel(k_left); |
| |
| <span class="kw">let </span>k_right = image.get_pixel(left + <span class="number">1</span>, x); |
| sum_right.add_pixel(k_right); |
| } |
| |
| <span class="comment">// Now we approximate: left/n*(1-fract) + right/n*fract |
| </span><span class="kw">let </span>fact_right = fract /((top - bottom) <span class="kw">as </span>f32); |
| <span class="kw">let </span>fact_left = (<span class="number">1. </span>- fract)/((top - bottom) <span class="kw">as </span>f32); |
| |
| <span class="kw">let </span>mix_left_and_right = |leftv: S::Larger, rightv: S::Larger| |
| <S <span class="kw">as </span>NumCast>::from( |
| fact_left * leftv.to_f32().unwrap() + |
| fact_right * rightv.to_f32().unwrap() |
| ).expect(<span class="string">"Average sample value should fit into sample type"</span>); |
| |
| ( |
| mix_left_and_right(sum_left.<span class="number">0</span>, sum_right.<span class="number">0</span>), |
| mix_left_and_right(sum_left.<span class="number">1</span>, sum_right.<span class="number">1</span>), |
| mix_left_and_right(sum_left.<span class="number">2</span>, sum_right.<span class="number">2</span>), |
| mix_left_and_right(sum_left.<span class="number">3</span>, sum_right.<span class="number">3</span>), |
| ) |
| } |
| |
| <span class="doccomment">/// Get a thumbnail pixel where the input window encloses at least a horizontal pixel. |
| </span><span class="kw">fn </span>thumbnail_sample_fraction_vertical<I, P, S>( |
| image: <span class="kw-2">&</span>I, |
| left: u32, |
| right: u32, |
| bottom: u32, |
| fraction_vertical: f32, |
| ) -> (S, S, S, S) |
| <span class="kw">where |
| </span>I: GenericImageView<Pixel = P>, |
| P: Pixel<Subpixel = S>, |
| S: Primitive + Enlargeable, |
| { |
| <span class="kw">let </span>fract = fraction_vertical; |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>sum_bot = ThumbnailSum::zeroed(); |
| <span class="kw">let </span><span class="kw-2">mut </span>sum_top = ThumbnailSum::zeroed(); |
| <span class="kw">for </span>x <span class="kw">in </span>left..right { |
| <span class="kw">let </span>k_bot = image.get_pixel(x, bottom); |
| sum_bot.add_pixel(k_bot); |
| |
| <span class="kw">let </span>k_top = image.get_pixel(x, bottom + <span class="number">1</span>); |
| sum_top.add_pixel(k_top); |
| } |
| |
| <span class="comment">// Now we approximate: bot/n*fract + top/n*(1-fract) |
| </span><span class="kw">let </span>fact_top = fract /((right - left) <span class="kw">as </span>f32); |
| <span class="kw">let </span>fact_bot = (<span class="number">1. </span>- fract)/((right - left) <span class="kw">as </span>f32); |
| |
| <span class="kw">let </span>mix_bot_and_top = |botv: S::Larger, topv: S::Larger| |
| <S <span class="kw">as </span>NumCast>::from( |
| fact_bot * botv.to_f32().unwrap() + |
| fact_top * topv.to_f32().unwrap() |
| ).expect(<span class="string">"Average sample value should fit into sample type"</span>); |
| |
| ( |
| mix_bot_and_top(sum_bot.<span class="number">0</span>, sum_top.<span class="number">0</span>), |
| mix_bot_and_top(sum_bot.<span class="number">1</span>, sum_top.<span class="number">1</span>), |
| mix_bot_and_top(sum_bot.<span class="number">2</span>, sum_top.<span class="number">2</span>), |
| mix_bot_and_top(sum_bot.<span class="number">3</span>, sum_top.<span class="number">3</span>), |
| ) |
| } |
| |
| <span class="doccomment">/// Get a single pixel for a thumbnail where the input window does not enclose any full pixel. |
| </span><span class="kw">fn </span>thumbnail_sample_fraction_both<I, P, S>( |
| image: <span class="kw-2">&</span>I, |
| left: u32, |
| fraction_vertical: f32, |
| bottom: u32, |
| fraction_horizontal: f32, |
| ) -> (S, S, S, S) |
| <span class="kw">where |
| </span>I: GenericImageView<Pixel = P>, |
| P: Pixel<Subpixel = S>, |
| S: Primitive + Enlargeable, |
| { |
| <span class="kw">let </span>k_bl = image.get_pixel(left, bottom ).channels4(); |
| <span class="kw">let </span>k_tl = image.get_pixel(left, bottom + <span class="number">1</span>).channels4(); |
| <span class="kw">let </span>k_br = image.get_pixel(left + <span class="number">1</span>, bottom ).channels4(); |
| <span class="kw">let </span>k_tr = image.get_pixel(left + <span class="number">1</span>, bottom + <span class="number">1</span>).channels4(); |
| |
| <span class="kw">let </span>frac_v = fraction_vertical; |
| <span class="kw">let </span>frac_h = fraction_horizontal; |
| |
| <span class="kw">let </span>fact_tr = frac_v * frac_h; |
| <span class="kw">let </span>fact_tl = frac_v * (<span class="number">1. </span>- frac_h); |
| <span class="kw">let </span>fact_br = (<span class="number">1. </span>- frac_v) * frac_h; |
| <span class="kw">let </span>fact_bl = (<span class="number">1. </span>- frac_v) * (<span class="number">1. </span>- frac_h); |
| |
| <span class="kw">let </span>mix = |br: S, tr: S, bl: S, tl: S| |
| <S <span class="kw">as </span>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(<span class="string">"Average sample value should fit into sample type"</span>); |
| |
| ( |
| mix(k_br.<span class="number">0</span>, k_tr.<span class="number">0</span>, k_bl.<span class="number">0</span>, k_tl.<span class="number">0</span>), |
| mix(k_br.<span class="number">1</span>, k_tr.<span class="number">1</span>, k_bl.<span class="number">1</span>, k_tl.<span class="number">1</span>), |
| mix(k_br.<span class="number">2</span>, k_tr.<span class="number">2</span>, k_bl.<span class="number">2</span>, k_tl.<span class="number">2</span>), |
| mix(k_br.<span class="number">3</span>, k_tr.<span class="number">3</span>, k_bl.<span class="number">3</span>, k_tl.<span class="number">3</span>), |
| ) |
| } |
| |
| <span class="doccomment">/// Perform a 3x3 box filter on the supplied image. |
| /// ```kernel``` is an array of the filter weights of length 9. |
| </span><span class="kw">pub fn </span>filter3x3<I, P, S>(image: <span class="kw-2">&</span>I, kernel: <span class="kw-2">&</span>[f32]) -> ImageBuffer<P, Vec<S>> |
| <span class="kw">where |
| </span>I: GenericImageView<Pixel = P>, |
| P: Pixel<Subpixel = S> + <span class="lifetime">'static</span>, |
| S: Primitive + <span class="lifetime">'static</span>, |
| { |
| <span class="comment">// The kernel's input positions relative to the current pixel. |
| </span><span class="kw">let </span>taps: <span class="kw-2">&</span>[(isize, isize)] = <span class="kw-2">&</span>[ |
| (-<span class="number">1</span>, -<span class="number">1</span>), |
| (<span class="number">0</span>, -<span class="number">1</span>), |
| (<span class="number">1</span>, -<span class="number">1</span>), |
| (-<span class="number">1</span>, <span class="number">0</span>), |
| (<span class="number">0</span>, <span class="number">0</span>), |
| (<span class="number">1</span>, <span class="number">0</span>), |
| (-<span class="number">1</span>, <span class="number">1</span>), |
| (<span class="number">0</span>, <span class="number">1</span>), |
| (<span class="number">1</span>, <span class="number">1</span>), |
| ]; |
| |
| <span class="kw">let </span>(width, height) = image.dimensions(); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>out = ImageBuffer::new(width, height); |
| |
| <span class="kw">let </span>max = S::max_value(); |
| <span class="kw">let </span>max: f32 = NumCast::from(max).unwrap(); |
| |
| <span class="kw">let </span>sum = <span class="kw">match </span>kernel.iter().fold(<span class="number">0.0</span>, |s, <span class="kw-2">&</span>item| s + item) { |
| x <span class="kw">if </span>x == <span class="number">0.0 </span>=> <span class="number">1.0</span>, |
| sum => sum, |
| }; |
| <span class="kw">let </span>sum = (sum, sum, sum, sum); |
| |
| <span class="kw">for </span>y <span class="kw">in </span><span class="number">1</span>..height - <span class="number">1 </span>{ |
| <span class="kw">for </span>x <span class="kw">in </span><span class="number">1</span>..width - <span class="number">1 </span>{ |
| <span class="kw">let </span><span class="kw-2">mut </span>t = (<span class="number">0.0</span>, <span class="number">0.0</span>, <span class="number">0.0</span>, <span class="number">0.0</span>); |
| |
| <span class="comment">// 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. |
| </span><span class="kw">for </span>(<span class="kw-2">&</span>k, <span class="kw-2">&</span>(a, b)) <span class="kw">in </span>kernel.iter().zip(taps.iter()) { |
| <span class="kw">let </span>k = (k, k, k, k); |
| <span class="kw">let </span>x0 = x <span class="kw">as </span>isize + a; |
| <span class="kw">let </span>y0 = y <span class="kw">as </span>isize + b; |
| |
| <span class="kw">let </span>p = image.get_pixel(x0 <span class="kw">as </span>u32, y0 <span class="kw">as </span>u32); |
| |
| <span class="kw">let </span>(k1, k2, k3, k4) = p.channels4(); |
| |
| <span class="kw">let </span>vec: (f32, f32, f32, f32) = ( |
| NumCast::from(k1).unwrap(), |
| NumCast::from(k2).unwrap(), |
| NumCast::from(k3).unwrap(), |
| NumCast::from(k4).unwrap(), |
| ); |
| |
| t.<span class="number">0 </span>+= vec.<span class="number">0 </span>* k.<span class="number">0</span>; |
| t.<span class="number">1 </span>+= vec.<span class="number">1 </span>* k.<span class="number">1</span>; |
| t.<span class="number">2 </span>+= vec.<span class="number">2 </span>* k.<span class="number">2</span>; |
| t.<span class="number">3 </span>+= vec.<span class="number">3 </span>* k.<span class="number">3</span>; |
| } |
| |
| <span class="kw">let </span>(t1, t2, t3, t4) = (t.<span class="number">0 </span>/ sum.<span class="number">0</span>, t.<span class="number">1 </span>/ sum.<span class="number">1</span>, t.<span class="number">2 </span>/ sum.<span class="number">2</span>, t.<span class="number">3 </span>/ sum.<span class="number">3</span>); |
| |
| <span class="kw">let </span>t = Pixel::from_channels( |
| NumCast::from(clamp(t1, <span class="number">0.0</span>, max)).unwrap(), |
| NumCast::from(clamp(t2, <span class="number">0.0</span>, max)).unwrap(), |
| NumCast::from(clamp(t3, <span class="number">0.0</span>, max)).unwrap(), |
| NumCast::from(clamp(t4, <span class="number">0.0</span>, max)).unwrap(), |
| ); |
| |
| out.put_pixel(x, y, t); |
| } |
| } |
| |
| out |
| } |
| |
| <span class="doccomment">/// Resize the supplied image to the specified dimensions. |
| /// ```nwidth``` and ```nheight``` are the new dimensions. |
| /// ```filter``` is the sampling filter to use. |
| </span><span class="kw">pub fn </span>resize<I: GenericImageView>( |
| image: <span class="kw-2">&</span>I, |
| nwidth: u32, |
| nheight: u32, |
| filter: FilterType, |
| ) -> ImageBuffer<I::Pixel, Vec<<I::Pixel <span class="kw">as </span>Pixel>::Subpixel>> |
| <span class="kw">where |
| </span>I::Pixel: <span class="lifetime">'static</span>, |
| <I::Pixel <span class="kw">as </span>Pixel>::Subpixel: <span class="lifetime">'static</span>, |
| { |
| <span class="kw">let </span><span class="kw-2">mut </span>method = <span class="kw">match </span>filter { |
| FilterType::Nearest => Filter { |
| kernel: Box::new(box_kernel), |
| support: <span class="number">0.0</span>, |
| }, |
| FilterType::Triangle => Filter { |
| kernel: Box::new(triangle_kernel), |
| support: <span class="number">1.0</span>, |
| }, |
| FilterType::CatmullRom => Filter { |
| kernel: Box::new(catmullrom_kernel), |
| support: <span class="number">2.0</span>, |
| }, |
| FilterType::Gaussian => Filter { |
| kernel: Box::new(gaussian_kernel), |
| support: <span class="number">3.0</span>, |
| }, |
| FilterType::Lanczos3 => Filter { |
| kernel: Box::new(lanczos3_kernel), |
| support: <span class="number">3.0</span>, |
| }, |
| }; |
| |
| <span class="kw">let </span>tmp = vertical_sample(image, nheight, <span class="kw-2">&mut </span>method); |
| horizontal_sample(<span class="kw-2">&</span>tmp, nwidth, <span class="kw-2">&mut </span>method) |
| } |
| |
| <span class="doccomment">/// Performs a Gaussian blur on the supplied image. |
| /// ```sigma``` is a measure of how much to blur by. |
| </span><span class="kw">pub fn </span>blur<I: GenericImageView>( |
| image: <span class="kw-2">&</span>I, |
| sigma: f32, |
| ) -> ImageBuffer<I::Pixel, Vec<<I::Pixel <span class="kw">as </span>Pixel>::Subpixel>> |
| <span class="kw">where |
| </span>I::Pixel: <span class="lifetime">'static</span>, |
| { |
| <span class="kw">let </span>sigma = <span class="kw">if </span>sigma <= <span class="number">0.0 </span>{ <span class="number">1.0 </span>} <span class="kw">else </span>{ sigma }; |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>method = Filter { |
| kernel: Box::new(|x| gaussian(x, sigma)), |
| support: <span class="number">2.0 </span>* sigma, |
| }; |
| |
| <span class="kw">let </span>(width, height) = image.dimensions(); |
| |
| <span class="comment">// Keep width and height the same for horizontal and |
| // vertical sampling. |
| </span><span class="kw">let </span>tmp = vertical_sample(image, height, <span class="kw-2">&mut </span>method); |
| horizontal_sample(<span class="kw-2">&</span>tmp, width, <span class="kw-2">&mut </span>method) |
| } |
| |
| <span class="doccomment">/// 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> |
| </span><span class="kw">pub fn </span>unsharpen<I, P, S>(image: <span class="kw-2">&</span>I, sigma: f32, threshold: i32) -> ImageBuffer<P, Vec<S>> |
| <span class="kw">where |
| </span>I: GenericImageView<Pixel = P>, |
| P: Pixel<Subpixel = S> + <span class="lifetime">'static</span>, |
| S: Primitive + <span class="lifetime">'static</span>, |
| { |
| <span class="kw">let </span><span class="kw-2">mut </span>tmp = blur(image, sigma); |
| |
| <span class="kw">let </span>max = S::max_value(); |
| <span class="kw">let </span>max: i32 = NumCast::from(max).unwrap(); |
| <span class="kw">let </span>(width, height) = image.dimensions(); |
| |
| <span class="kw">for </span>y <span class="kw">in </span><span class="number">0</span>..height { |
| <span class="kw">for </span>x <span class="kw">in </span><span class="number">0</span>..width { |
| <span class="kw">let </span>a = image.get_pixel(x, y); |
| <span class="kw">let </span>b = tmp.get_pixel_mut(x, y); |
| |
| <span class="kw">let </span>p = a.map2(b, |c, d| { |
| <span class="kw">let </span>ic: i32 = NumCast::from(c).unwrap(); |
| <span class="kw">let </span>id: i32 = NumCast::from(d).unwrap(); |
| |
| <span class="kw">let </span>diff = (ic - id).abs(); |
| |
| <span class="kw">if </span>diff > threshold { |
| <span class="kw">let </span>e = clamp(ic + diff, <span class="number">0</span>, max); |
| |
| NumCast::from(e).unwrap() |
| } <span class="kw">else </span>{ |
| c |
| } |
| }); |
| |
| <span class="kw-2">*</span>b = p; |
| } |
| } |
| |
| tmp |
| } |
| |
| <span class="attribute">#[cfg(test)] |
| </span><span class="kw">mod </span>tests { |
| <span class="kw">use super</span>::{resize, FilterType}; |
| <span class="kw">use crate</span>::{ImageBuffer, RgbImage}; |
| <span class="attribute">#[cfg(feature = <span class="string">"benchmarks"</span>)] |
| </span><span class="kw">use </span>test; |
| |
| <span class="attribute">#[bench] |
| #[cfg(all(feature = <span class="string">"benchmarks"</span>, feature = <span class="string">"png"</span>))] |
| </span><span class="kw">fn </span>bench_resize(b: <span class="kw-2">&mut </span>test::Bencher) { |
| <span class="kw">use </span>std::path::Path; |
| <span class="kw">let </span>img = <span class="kw">crate</span>::open(<span class="kw-2">&</span>Path::new(<span class="string">"./examples/fractal.png"</span>)).unwrap(); |
| b.iter(|| { |
| test::black_box(resize(<span class="kw-2">&</span>img, <span class="number">200</span>, <span class="number">200</span>, FilterType::Nearest)); |
| }); |
| b.bytes = <span class="number">800 </span>* <span class="number">800 </span>* <span class="number">3 </span>+ <span class="number">200 </span>* <span class="number">200 </span>* <span class="number">3</span>; |
| } |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>test_issue_186() { |
| <span class="kw">let </span>img: RgbImage = ImageBuffer::new(<span class="number">100</span>, <span class="number">100</span>); |
| <span class="kw">let _ </span>= resize(<span class="kw-2">&</span>img, <span class="number">50</span>, <span class="number">50</span>, FilterType::Lanczos3); |
| } |
| |
| <span class="attribute">#[bench] |
| #[cfg(all(feature = <span class="string">"benchmarks"</span>, feature = <span class="string">"tiff"</span>))] |
| </span><span class="kw">fn </span>bench_thumbnail(b: <span class="kw-2">&mut </span>test::Bencher) { |
| <span class="kw">let </span>path = <span class="macro">concat!</span>(<span class="macro">env!</span>(<span class="string">"CARGO_MANIFEST_DIR"</span>), <span class="string">"/tests/images/tiff/testsuite/mandrill.tiff"</span>); |
| <span class="kw">let </span>image = <span class="kw">crate</span>::open(path).unwrap(); |
| b.iter(|| { |
| test::black_box(image.thumbnail(<span class="number">256</span>, <span class="number">256</span>)); |
| }); |
| b.bytes = <span class="number">512 </span>* <span class="number">512 </span>* <span class="number">4 </span>+ <span class="number">256 </span>* <span class="number">256 </span>* <span class="number">4</span>; |
| } |
| |
| <span class="attribute">#[bench] |
| #[cfg(all(feature = <span class="string">"benchmarks"</span>, feature = <span class="string">"tiff"</span>))] |
| </span><span class="kw">fn </span>bench_thumbnail_upsize(b: <span class="kw-2">&mut </span>test::Bencher) { |
| <span class="kw">let </span>path = <span class="macro">concat!</span>(<span class="macro">env!</span>(<span class="string">"CARGO_MANIFEST_DIR"</span>), <span class="string">"/tests/images/tiff/testsuite/mandrill.tiff"</span>); |
| <span class="kw">let </span>image = <span class="kw">crate</span>::open(path).unwrap().thumbnail(<span class="number">256</span>, <span class="number">256</span>); |
| b.iter(|| { |
| test::black_box(image.thumbnail(<span class="number">512</span>, <span class="number">512</span>)); |
| }); |
| b.bytes = <span class="number">512 </span>* <span class="number">512 </span>* <span class="number">4 </span>+ <span class="number">256 </span>* <span class="number">256 </span>* <span class="number">4</span>; |
| } |
| |
| <span class="attribute">#[bench] |
| #[cfg(all(feature = <span class="string">"benchmarks"</span>, feature = <span class="string">"tiff"</span>))] |
| </span><span class="kw">fn </span>bench_thumbnail_upsize_irregular(b: <span class="kw-2">&mut </span>test::Bencher) { |
| <span class="kw">let </span>path = <span class="macro">concat!</span>(<span class="macro">env!</span>(<span class="string">"CARGO_MANIFEST_DIR"</span>), <span class="string">"/tests/images/tiff/testsuite/mandrill.tiff"</span>); |
| <span class="kw">let </span>image = <span class="kw">crate</span>::open(path).unwrap().thumbnail(<span class="number">193</span>, <span class="number">193</span>); |
| b.iter(|| { |
| test::black_box(image.thumbnail(<span class="number">256</span>, <span class="number">256</span>)); |
| }); |
| b.bytes = <span class="number">193 </span>* <span class="number">193 </span>* <span class="number">4 </span>+ <span class="number">256 </span>* <span class="number">256 </span>* <span class="number">4</span>; |
| } |
| |
| <span class="attribute">#[test] |
| #[cfg(feature = <span class="string">"png"</span>)] |
| </span><span class="kw">fn </span>resize_transparent_image() { |
| <span class="kw">use </span><span class="kw">super</span>::FilterType::{CatmullRom, Gaussian, Lanczos3, Nearest, Triangle}; |
| <span class="kw">use </span><span class="kw">crate</span>::imageops::crop_imm; |
| <span class="kw">use </span><span class="kw">crate</span>::RgbaImage; |
| |
| <span class="kw">fn </span>assert_resize(image: <span class="kw-2">&</span>RgbaImage, filter: FilterType) { |
| <span class="kw">let </span>resized = resize(image, <span class="number">16</span>, <span class="number">16</span>, filter); |
| <span class="kw">let </span>cropped = crop_imm(<span class="kw-2">&</span>resized, <span class="number">5</span>, <span class="number">5</span>, <span class="number">6</span>, <span class="number">6</span>).to_image(); |
| <span class="kw">for </span>pixel <span class="kw">in </span>cropped.pixels() { |
| <span class="kw">let </span>alpha = pixel.<span class="number">0</span>[<span class="number">3</span>]; |
| <span class="macro">assert!</span>( |
| alpha != <span class="number">254 </span>&& alpha != <span class="number">253</span>, |
| <span class="macro">format!</span>(<span class="string">"alpha value: {}, {:?}"</span>, alpha, filter) |
| ); |
| } |
| } |
| |
| <span class="kw">let </span>path = <span class="macro">concat!</span>( |
| <span class="macro">env!</span>(<span class="string">"CARGO_MANIFEST_DIR"</span>), |
| <span class="string">"/tests/images/png/transparency/tp1n3p08.png" |
| </span>); |
| <span class="kw">let </span>img = <span class="kw">crate</span>::open(path).unwrap(); |
| <span class="kw">let </span>rgba8 = img.as_rgba8().unwrap(); |
| <span class="kw">let </span>filters = <span class="kw-2">&</span>[Nearest, Triangle, CatmullRom, Gaussian, Lanczos3]; |
| <span class="kw">for </span>filter <span class="kw">in </span>filters { |
| assert_resize(rgba8, filter.clone()); |
| } |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="image" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
