//! 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 num_traits::{NumCast, ToPrimitive, Zero}; use std::f32; use std::ops::Mul; use crate::imageops::filter_1d::{ filter_2d_sep_la, filter_2d_sep_la_f32, filter_2d_sep_la_u16, filter_2d_sep_plane, filter_2d_sep_plane_f32, filter_2d_sep_plane_u16, filter_2d_sep_rgb, filter_2d_sep_rgb_f32, filter_2d_sep_rgb_u16, filter_2d_sep_rgba, filter_2d_sep_rgba_f32, filter_2d_sep_rgba_u16, FilterImageSize, }; use crate::images::buffer::{Gray16Image, GrayAlpha16Image, Rgb16Image, Rgba16Image}; use crate::traits::{Enlargeable, Pixel, Primitive}; use crate::utils::clamp; use crate::{ DynamicImage, GenericImage, GenericImageView, GrayAlphaImage, GrayImage, ImageBuffer, Rgb32FImage, RgbImage, Rgba32FImage, RgbaImage, }; /// 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/main/examples/scaledown) /// and /// [`scaleup`](https://github.com/image-rs/image/tree/main/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/main/examples/scaledown/test.jpg) /// that has been scaled down to 300x225 px: /// /// ///
///
///
/// Nearest Neighbor ///
///
///
/// Linear: Triangle ///
///
///
/// Cubic: Catmull-Rom ///
///
///
/// Gaussian ///
///
///
/// Lanczos with window 3 ///
///
/// /// ## Speed /// /// Time required to create each of the examples above, tested on an Intel /// i7-4770 CPU with Rust 1.37 in release mode: /// /// /// /// /// /// /// /// /// /// /// /// /// /// /// /// /// /// /// /// /// /// ///
Nearest31 ms
Triangle414 ms
CatmullRom817 ms
Gaussian1180 ms
Lanczos31170 ms
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)] #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))] 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 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 { self.0.round().to_i8() } fn to_i16(&self) -> Option { self.0.round().to_i16() } fn to_i64(&self) -> Option { self.0.round().to_i64() } fn to_u8(&self) -> Option { self.0.round().to_u8() } fn to_u16(&self) -> Option { self.0.round().to_u16() } fn to_u64(&self) -> Option { self.0.round().to_u64() } fn to_f64(&self) -> Option { 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. // // Note: if an empty image is passed in, panics unless the image is truly empty. fn horizontal_sample( image: &Rgba32FImage, new_width: u32, filter: &mut Filter, ) -> ImageBuffer> where P: Pixel + 'static, S: Primitive + 'static, { let (width, height) = image.dimensions(); // This is protection against a memory usage similar to #2340. See `vertical_sample`. assert!( // Checks the implication: (width == 0) -> (height == 0) width != 0 || height == 0, "Unexpected prior allocation size. This case should have been handled by the caller" ); let mut out = ImageBuffer::new(new_width, height); out.copy_color_space_from(image); 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, >::from(width) - 1) as u32; let right = (inputx + src_support).ceil() as i64; let right = clamp( right, >::from(left) + 1, >::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 w in ws.iter_mut() { *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( img: &impl GenericImageView, u: f32, v: f32, ) -> Option

{ 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( img: &impl GenericImageView, u: f32, v: f32, ) -> Option

{ 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( img: &impl GenericImageView, x: f32, y: f32, ) -> Option

{ 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( img: &impl GenericImageView, x: f32, y: f32, ) -> Option

{ // assumption needed for correctness of pixel creation assert!(P::CHANNEL_COUNT <= 4); 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; } // keep these as integers, for fewer FLOPs let uf = x.floor() as u32; let vf = y.floor() as u32; let uc = (uf + 1).min(w - 1); let vc = (vf + 1).min(h - 1); // clamp coords to the range of the image let mut sxx = [[0.; 4]; 4]; // do not use Array::map, as it can be slow with high stack usage, // for [[f32; 4]; 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 mut compute = |u: u32, v: u32, i| { let s = img.get_pixel(u, v); for (j, c) in s.channels().iter().enumerate() { sxx[j][i] = c.to_f32().unwrap(); } s }; // hacky reuse since cannot construct a generic Pixel let mut out: P = compute(uf, vf, 0); compute(uf, vc, 1); compute(uc, vf, 2); compute(uc, vc, 3); // weights, the later two are independent from the first 2 for better vectorization. let ufw = x - uf as f32; let vfw = y - vf as f32; let ucw = (uf + 1) as f32 - x; let vcw = (vf + 1) as f32 - y; // 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; // was originally assert, but is actually not a cheap computation debug_assert!(f32::abs((wff + wfc + wcf + wcc) - 1.) < 1e-3); // hack to see if primitive is an integer or a float let is_float = P::Subpixel::DEFAULT_MAX_VALUE.to_f32().unwrap() == 1.0; for (i, c) in out.channels_mut().iter_mut().enumerate() { let v = wff * sxx[i][0] + wfc * sxx[i][1] + wcf * sxx[i][2] + wcc * sxx[i][3]; // this rounding may introduce quantization errors, // Specifically what is meant is that many samples may deviate // from the mean value of the originals, but it's not possible to fix that. *c = ::from(if is_float { v } else { 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. // // Note: if an empty image is passed in, panics unless the image is truly empty. fn vertical_sample(image: &I, new_height: u32, filter: &mut Filter) -> Rgba32FImage where I: GenericImageView, P: Pixel + 'static, S: Primitive + 'static, { let (width, height) = image.dimensions(); // This is protection against a regression in memory usage such as #2340. Since the strategy to // deal with it depends on the caller it is a precondition of this function. assert!( // Checks the implication: (height == 0) -> (width == 0) height != 0 || width == 0, "Unexpected prior allocation size. This case should have been handled by the caller" ); let mut out = ImageBuffer::new(width, new_height); out.copy_color_space_from(&image.buffer_with_dimensions(0, 0)); 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, >::from(height) - 1) as u32; let right = (inputy + src_support).ceil() as i64; let right = clamp( right, >::from(left) + 1, >::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 w in ws.iter_mut() { *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::Larger, S::Larger, S::Larger, S::Larger); impl ThumbnailSum { fn zeroed() -> Self { ThumbnailSum( S::Larger::zero(), S::Larger::zero(), S::Larger::zero(), S::Larger::zero(), ) } fn sample_val(val: S) -> S::Larger { ::from(val).unwrap() } fn add_pixel>(&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(image: &I, new_width: u32, new_height: u32) -> ImageBuffer> where I: GenericImageView, P: Pixel + 'static, S: Primitive + Enlargeable + 'static, { let (width, height) = image.dimensions(); let mut out = image.buffer_with_dimensions(new_width, new_height); if height == 0 || width == 0 { return out; } 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( image: &I, left: u32, right: u32, bottom: u32, top: u32, ) -> (S, S, S, S) where I: GenericImageView, P: Pixel, 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 = ::from((right - left) * (top - bottom)).unwrap(); let round = ::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( image: &I, left: u32, fraction_horizontal: f32, bottom: u32, top: u32, ) -> (S, S, S, S) where I: GenericImageView, P: Pixel, 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| { ::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( image: &I, left: u32, right: u32, bottom: u32, fraction_vertical: f32, ) -> (S, S, S, S) where I: GenericImageView, P: Pixel, 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| { ::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( image: &I, left: u32, fraction_vertical: f32, bottom: u32, fraction_horizontal: f32, ) -> (S, S, S, S) where I: GenericImageView, P: Pixel, 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| { ::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. /// /// # Arguments: /// /// * `image` - source image. /// * `kernel` - is an array of the filter weights of length 9. /// /// This method typically assumes that the input is scene-linear light. /// If it is not, color distortion may occur. pub fn filter3x3(image: &I, kernel: &[f32]) -> ImageBuffer> where I: GenericImageView, P: Pixel + '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 = image.buffer_like(); let max = S::DEFAULT_MAX_VALUE; let max: f32 = NumCast::from(max).unwrap(); #[allow(clippy::redundant_guards)] 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. /// /// # Arguments: /// /// * `nwidth` - new image width. /// * `nheight` - new image height. /// * `filter` - is the sampling filter to use, see [FilterType] for mor information. /// /// This method assumes alpha pre-multiplication for images that contain non-constant alpha. /// /// This method typically assumes that the input is scene-linear light. /// If it is not, color distortion may occur. pub fn resize( image: &I, nwidth: u32, nheight: u32, filter: FilterType, ) -> ImageBuffer::Subpixel>> where I::Pixel: 'static, ::Subpixel: 'static, { // Check if there is nothing to sample from. let is_empty = { let (width, height) = image.dimensions(); width == 0 || height == 0 }; if is_empty { return image.buffer_with_dimensions(nwidth, nheight); } // 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 = image.buffer_like(); 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. /// /// # Arguments /// /// - `sigma` - gaussian bell flattening level. /// /// Use [`crate::imageops::fast_blur()`] for a faster but less /// accurate version. /// This method assumes alpha pre-multiplication for images that contain non-constant alpha. /// This method typically assumes that the input is scene-linear light. /// If it is not, color distortion may occur. pub fn blur( image: &I, sigma: f32, ) -> ImageBuffer::Subpixel>> where I::Pixel: 'static, { gaussian_blur_indirect( image, GaussianBlurParameters::new_from_sigma(if sigma == 0.0 { 0.8 } else { sigma }), ) } /// Performs a Gaussian blur on the supplied image. /// /// # Arguments /// /// - `parameters` - see [GaussianBlurParameters] for more info. /// /// This method assumes alpha pre-multiplication for images that contain non-constant alpha. /// This method typically assumes that the input is scene-linear light. /// If it is not, color distortion may occur. pub fn blur_advanced( image: &I, parameters: GaussianBlurParameters, ) -> ImageBuffer::Subpixel>> where I::Pixel: 'static, { gaussian_blur_indirect(image, parameters) } fn get_gaussian_kernel_1d(width: usize, sigma: f32) -> Vec { let mut sum_norm: f32 = 0f32; let mut kernel = vec![0f32; width]; let scale = 1f32 / (f32::sqrt(2f32 * f32::consts::PI) * sigma); let mean = (width / 2) as f32; for (x, weight) in kernel.iter_mut().enumerate() { let new_weight = f32::exp(-0.5f32 * f32::powf((x as f32 - mean) / sigma, 2.0f32)) * scale; *weight = new_weight; sum_norm += new_weight; } if sum_norm != 0f32 { let sum_scale = 1f32 / sum_norm; for weight in &mut kernel { *weight = weight.mul(sum_scale); } } kernel } /// Holds analytical gaussian blur representation #[derive(Copy, Clone, PartialOrd, PartialEq)] pub struct GaussianBlurParameters { /// X-axis kernel, must be odd x_axis_kernel_size: u32, /// X-axis sigma, must > 0, not subnormal, and not NaN x_axis_sigma: f32, /// Y-axis kernel, must be odd y_axis_kernel_size: u32, /// Y-axis sigma, must > 0, not subnormal, and not NaN y_axis_sigma: f32, } impl GaussianBlurParameters { /// Built-in smoothing kernel with size 3. pub const SMOOTHING_3: GaussianBlurParameters = GaussianBlurParameters { x_axis_kernel_size: 3, x_axis_sigma: 0.8, y_axis_kernel_size: 3, y_axis_sigma: 0.8, }; /// Built-in smoothing kernel with size 5. pub const SMOOTHING_5: GaussianBlurParameters = GaussianBlurParameters { x_axis_kernel_size: 5, x_axis_sigma: 1.1, y_axis_kernel_size: 5, y_axis_sigma: 1.1, }; /// Built-in smoothing kernel with size 7. pub const SMOOTHING_7: GaussianBlurParameters = GaussianBlurParameters { x_axis_kernel_size: 7, x_axis_sigma: 1.4, y_axis_kernel_size: 7, y_axis_sigma: 1.4, }; /// Creates a new parameters set from radius only. pub fn new_from_radius(radius: f32) -> GaussianBlurParameters { // Previous implementation was allowing passing 0 so we'll allow here also. assert!(radius >= 0.0); if radius != 0. { assert!( radius.is_normal(), "Radius do not allow infinities, NaNs or subnormals" ); } GaussianBlurParameters::new_from_kernel_size(radius * 2. + 1.) } /// Creates a new parameters set from kernel size only. /// /// Kernel size will be rounded to nearest odd, and used with fraction /// to compute accurate required sigma. pub fn new_from_kernel_size(kernel_size: f32) -> GaussianBlurParameters { assert!( kernel_size > 0., "Kernel size do not allow infinities, zeros, NaNs or subnormals or negatives" ); assert!( kernel_size.is_normal(), "Kernel size do not allow infinities, zeros, NaNs or subnormals or negatives" ); let i_kernel_size = GaussianBlurParameters::round_to_nearest_odd(kernel_size); assert_ne!(i_kernel_size % 2, 0, "Kernel size must be odd"); let v_sigma = GaussianBlurParameters::sigma_size(kernel_size); GaussianBlurParameters { x_axis_kernel_size: i_kernel_size, x_axis_sigma: v_sigma, y_axis_kernel_size: i_kernel_size, y_axis_sigma: v_sigma, } } /// Creates a new anisotropic parameter set from kernel sizes /// /// Kernel size will be rounded to nearest odd, and used with fraction /// to compute accurate required sigma. pub fn new_anisotropic_kernel_size( x_axis_kernel_size: f32, y_axis_kernel_size: f32, ) -> GaussianBlurParameters { assert!( x_axis_kernel_size > 0., "Kernel size do not allow infinities, zeros, NaNs or subnormals or negatives" ); assert!( y_axis_kernel_size.is_normal(), "Kernel size do not allow infinities, zeros, NaNs or subnormals or negatives" ); assert!( y_axis_kernel_size > 0., "Kernel size do not allow infinities, zeros, NaNs or subnormals or negatives" ); assert!( y_axis_kernel_size.is_normal(), "Kernel size do not allow infinities, zeros, NaNs or subnormals or negatives" ); let x_kernel_size = GaussianBlurParameters::round_to_nearest_odd(x_axis_kernel_size); assert_ne!(x_kernel_size % 2, 0, "Kernel size must be odd"); let y_kernel_size = GaussianBlurParameters::round_to_nearest_odd(y_axis_kernel_size); assert_ne!(y_kernel_size % 2, 0, "Kernel size must be odd"); let x_sigma = GaussianBlurParameters::sigma_size(x_axis_kernel_size); let y_sigma = GaussianBlurParameters::sigma_size(y_axis_kernel_size); GaussianBlurParameters { x_axis_kernel_size: x_kernel_size, x_axis_sigma: x_sigma, y_axis_kernel_size: y_kernel_size, y_axis_sigma: y_sigma, } } /// Creates a new parameters set from sigma only pub fn new_from_sigma(sigma: f32) -> GaussianBlurParameters { assert!( sigma.is_normal(), "Sigma cannot be NaN, Infinities, subnormal or zero" ); assert!(sigma > 0.0, "Sigma must be positive"); let kernel_size = GaussianBlurParameters::kernel_size_from_sigma(sigma); GaussianBlurParameters { x_axis_kernel_size: kernel_size, x_axis_sigma: sigma, y_axis_kernel_size: kernel_size, y_axis_sigma: sigma, } } #[inline] fn round_to_nearest_odd(x: f32) -> u32 { let n = x.round() as u32; if n % 2 != 0 { n } else { let lower = n - 1; let upper = n + 1; let dist_lower = (x - lower as f32).abs(); let dist_upper = (x - upper as f32).abs(); if dist_lower <= dist_upper { lower } else { upper } } } fn sigma_size(kernel_size: f32) -> f32 { let safe_kernel_size = if kernel_size <= 1. { 0.8 } else { kernel_size }; 0.3 * ((safe_kernel_size - 1.) * 0.5 - 1.) + 0.8 } fn kernel_size_from_sigma(sigma: f32) -> u32 { let possible_size = (((((sigma - 0.8) / 0.3) + 1.) * 2.) + 1.).max(3.) as u32; if possible_size % 2 == 0 { return possible_size + 1; } possible_size } } pub(crate) fn gaussian_blur_dyn_image( image: &DynamicImage, parameters: GaussianBlurParameters, ) -> DynamicImage { let x_axis_kernel = get_gaussian_kernel_1d( parameters.x_axis_kernel_size as usize, parameters.x_axis_sigma, ); let y_axis_kernel = get_gaussian_kernel_1d( parameters.y_axis_kernel_size as usize, parameters.y_axis_sigma, ); let filter_image_size = FilterImageSize { width: image.width() as usize, height: image.height() as usize, }; let mut target = match image { DynamicImage::ImageLuma8(img) => { let mut dest_image = vec![0u8; img.len()]; filter_2d_sep_plane( img.as_raw(), &mut dest_image, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); DynamicImage::ImageLuma8( GrayImage::from_raw(img.width(), img.height(), dest_image).unwrap(), ) } DynamicImage::ImageLumaA8(img) => { let mut dest_image = vec![0u8; img.len()]; filter_2d_sep_la( img.as_raw(), &mut dest_image, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); DynamicImage::ImageLumaA8( GrayAlphaImage::from_raw(img.width(), img.height(), dest_image).unwrap(), ) } DynamicImage::ImageRgb8(img) => { let mut dest_image = vec![0u8; img.len()]; filter_2d_sep_rgb( img.as_raw(), &mut dest_image, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); DynamicImage::ImageRgb8( RgbImage::from_raw(img.width(), img.height(), dest_image).unwrap(), ) } DynamicImage::ImageRgba8(img) => { let mut dest_image = vec![0u8; img.len()]; filter_2d_sep_rgba( img.as_raw(), &mut dest_image, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); DynamicImage::ImageRgba8( RgbaImage::from_raw(img.width(), img.height(), dest_image).unwrap(), ) } DynamicImage::ImageLuma16(img) => { let mut dest_image = vec![0u16; img.len()]; filter_2d_sep_plane_u16( img.as_raw(), &mut dest_image, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); DynamicImage::ImageLuma16( Gray16Image::from_raw(img.width(), img.height(), dest_image).unwrap(), ) } DynamicImage::ImageLumaA16(img) => { let mut dest_image = vec![0u16; img.len()]; filter_2d_sep_la_u16( img.as_raw(), &mut dest_image, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); DynamicImage::ImageLumaA16( GrayAlpha16Image::from_raw(img.width(), img.height(), dest_image).unwrap(), ) } DynamicImage::ImageRgb16(img) => { let mut dest_image = vec![0u16; img.len()]; filter_2d_sep_rgb_u16( img.as_raw(), &mut dest_image, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); DynamicImage::ImageRgb16( Rgb16Image::from_raw(img.width(), img.height(), dest_image).unwrap(), ) } DynamicImage::ImageRgba16(img) => { let mut dest_image = vec![0u16; img.len()]; filter_2d_sep_rgba_u16( img.as_raw(), &mut dest_image, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); DynamicImage::ImageRgba16( Rgba16Image::from_raw(img.width(), img.height(), dest_image).unwrap(), ) } DynamicImage::ImageRgb32F(img) => { let mut dest_image = vec![0f32; img.len()]; filter_2d_sep_rgb_f32( img.as_raw(), &mut dest_image, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); DynamicImage::ImageRgb32F( Rgb32FImage::from_raw(img.width(), img.height(), dest_image).unwrap(), ) } DynamicImage::ImageRgba32F(img) => { let mut dest_image = vec![0f32; img.len()]; filter_2d_sep_rgba_f32( img.as_raw(), &mut dest_image, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); DynamicImage::ImageRgba32F( Rgba32FImage::from_raw(img.width(), img.height(), dest_image).unwrap(), ) } }; // Must succeed. let _ = target.set_color_space(image.color_space()); target } fn gaussian_blur_indirect( image: &I, parameters: GaussianBlurParameters, ) -> ImageBuffer::Subpixel>> where I::Pixel: 'static, { match I::Pixel::CHANNEL_COUNT { 1 => gaussian_blur_indirect_impl::(image, parameters), 2 => gaussian_blur_indirect_impl::(image, parameters), 3 => gaussian_blur_indirect_impl::(image, parameters), 4 => gaussian_blur_indirect_impl::(image, parameters), _ => unimplemented!(), } } fn gaussian_blur_indirect_impl( image: &I, parameters: GaussianBlurParameters, ) -> ImageBuffer::Subpixel>> where I::Pixel: 'static, { let mut transient = vec![0f32; image.width() as usize * image.height() as usize * CN]; for (pixel, dst) in image.pixels().zip(transient.chunks_exact_mut(CN)) { let px = pixel.2.channels(); match CN { 1 => { dst[0] = NumCast::from(px[0]).unwrap(); } 2 => { dst[0] = NumCast::from(px[0]).unwrap(); dst[1] = NumCast::from(px[1]).unwrap(); } 3 => { dst[0] = NumCast::from(px[0]).unwrap(); dst[1] = NumCast::from(px[1]).unwrap(); dst[2] = NumCast::from(px[2]).unwrap(); } 4 => { dst[0] = NumCast::from(px[0]).unwrap(); dst[1] = NumCast::from(px[1]).unwrap(); dst[2] = NumCast::from(px[2]).unwrap(); dst[3] = NumCast::from(px[3]).unwrap(); } _ => unreachable!(), } } let mut transient_dst = vec![0.; image.width() as usize * image.height() as usize * CN]; let x_axis_kernel = get_gaussian_kernel_1d( parameters.x_axis_kernel_size as usize, parameters.x_axis_sigma, ); let y_axis_kernel = get_gaussian_kernel_1d( parameters.y_axis_kernel_size as usize, parameters.y_axis_sigma, ); let filter_image_size = FilterImageSize { width: image.width() as usize, height: image.height() as usize, }; match CN { 1 => { filter_2d_sep_plane_f32( &transient, &mut transient_dst, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); } 2 => { filter_2d_sep_la_f32( &transient, &mut transient_dst, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); } 3 => { filter_2d_sep_rgb_f32( &transient, &mut transient_dst, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); } 4 => { filter_2d_sep_rgba_f32( &transient, &mut transient_dst, filter_image_size, &x_axis_kernel, &y_axis_kernel, ) .unwrap(); } _ => unreachable!(), } let mut out = image.buffer_like(); for (dst, src) in out.pixels_mut().zip(transient_dst.chunks_exact_mut(CN)) { match CN { 1 => { let v0 = NumCast::from(FloatNearest(src[0])).unwrap(); #[allow(deprecated)] let t = Pixel::from_channels(v0, v0, v0, v0); *dst = t; } 2 => { let v0 = NumCast::from(FloatNearest(src[0])).unwrap(); let v1 = NumCast::from(FloatNearest(src[1])).unwrap(); #[allow(deprecated)] let t = Pixel::from_channels(v0, v1, v0, v0); *dst = t; } 3 => { let v0 = NumCast::from(FloatNearest(src[0])).unwrap(); let v1 = NumCast::from(FloatNearest(src[1])).unwrap(); let v2 = NumCast::from(FloatNearest(src[2])).unwrap(); #[allow(deprecated)] let t = Pixel::from_channels(v0, v1, v2, v0); *dst = t; } 4 => { let v0 = NumCast::from(FloatNearest(src[0])).unwrap(); let v1 = NumCast::from(FloatNearest(src[1])).unwrap(); let v2 = NumCast::from(FloatNearest(src[2])).unwrap(); let v3 = NumCast::from(FloatNearest(src[3])).unwrap(); #[allow(deprecated)] let t = Pixel::from_channels(v0, v1, v2, v3); *dst = t; } _ => unreachable!(), } } out } /// Performs an unsharpen mask on the supplied image. /// /// # Arguments: /// /// * `sigma` - is the amount to blur the image by. /// * `threshold` - is the threshold for minimal brightness change that will be sharpened. /// /// This method typically assumes that the input is scene-linear light. /// If it is not, color distortion may occur. /// /// See [Digital unsharp masking](https://en.wikipedia.org/wiki/Unsharp_masking#Digital_unsharp_masking) for more information. pub fn unsharpen(image: &I, sigma: f32, threshold: i32) -> ImageBuffer> where I: GenericImageView, P: Pixel + 'static, S: Primitive + 'static, { let mut tmp = blur_advanced(image, GaussianBlurParameters::new_from_sigma(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; if diff.abs() > 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])) ); } #[bench] #[cfg(feature = "benchmarks")] fn bench_sample_bilinear(b: &mut test::Bencher) { 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!(), }); b.iter(|| { sample_bilinear(&img, test::black_box(0.5), test::black_box(0.5)); }); } #[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 = u64::from(image.width() * image.height() * 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; } #[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)); } #[test] fn issue_2340() { let empty = crate::GrayImage::from_raw(1 << 31, 0, vec![]).unwrap(); // Really we're checking that no overflow / outsized allocation happens here. let result = resize(&empty, 1, 1, FilterType::Lanczos3); assert!(result.into_raw().into_iter().all(|c| c == 0)); // With the previous strategy before the regression this would allocate 1TB of memory for a // temporary during the sampling evaluation. let result = resize(&empty, 256, 256, FilterType::Lanczos3); assert!(result.into_raw().into_iter().all(|c| c == 0)); } #[test] fn issue_2340_refl() { // Tests the swapped coordinate version of `issue_2340`. let empty = crate::GrayImage::from_raw(0, 1 << 31, vec![]).unwrap(); let result = resize(&empty, 1, 1, FilterType::Lanczos3); assert!(result.into_raw().into_iter().all(|c| c == 0)); let result = resize(&empty, 256, 256, FilterType::Lanczos3); assert!(result.into_raw().into_iter().all(|c| c == 0)); } }