Struct GrayImage 

pub struct GrayImage {
    pub width: usize,
    pub height: usize,
    pub data: Vec<u8>,
}

Row-major 8-bit grayscale image.

Fields

width: usize

Width (pixels).

height: usize

Height (pixels).

data: Vec<u8>

Row-major pixel values (length width x height).

Implementations

impl GrayImage

pub fn new(width: usize, height: usize, data: Vec<u8>) -> Result<Self>

Builds from a buffer. Error if the length is not width x height.

pub fn filled(width: usize, height: usize, v: u8) -> Self

Image whose pixels are all v.

pub fn from_f32( width: usize, height: usize, f: impl Fn(usize, usize) -> f32, ) -> Self

Builds from a [0,1] real-valued image (rounding and saturation).

Examples found in repository

examples/bench_sift.rs (line 53)

fn main() {
    let args: Vec<String> = std::env::args().collect();
    let src = args.get(1).cloned().unwrap_or_else(|| "synthetic".into());
    let size: Option<(usize, usize)> = match (args.get(2), args.get(3)) {
        (Some(w), Some(h)) => Some((w.parse().expect("W"), h.parse().expect("H"))),
        _ => None,
    };
    let t = Instant::now();
    let mut g = if src == "synthetic" {
        let (w, h) = size.unwrap_or((2048, 1152));
        let mut s = 1u64;
        let mut noise = vec![0f32; w * h];
        for v in noise.iter_mut() {
            s = s.wrapping_mul(6364136223846793005).wrapping_add(1442695040888963407);
            *v = (s >> 40) as f32 / (1u64 << 24) as f32;
        }
        let mut out = vec![0f32; w * h];
        let mut tmp = vec![0f32; w * h];
        sift::pyramid::gaussian_blur(&noise, &mut out, &mut tmp, w, h, 2.0);
        GrayImage::from_f32(w, h, |x, y| (out[y * w + x] - 0.5) * 3.0 + 0.5)
    } else {
        read_gray(std::path::Path::new(&src)).expect("영상 읽기")
    };
    let t_read = t.elapsed();
    if let Some((w, h)) = size {
        if (w, h) != (g.width, g.height) {
            g = g.resized(w, h);
        }
    }
    println!("입력 {} ({}x{}), 읽기 {:.1} ms, 스레드 {}", src, g.width, g.height, t_read.as_secs_f64() * 1e3, rayon::current_num_threads());
    let sift = CpuSift::new();
    for (name, opts) in [("compat(기본)", SiftOptions::default()), ("무제한", SiftOptions { max_num_features: 0, ..Default::default() })]
    {
        let mut times = Vec::new();
        let mut n = 0;
        for _ in 0..5 {
            let t = Instant::now();
            let out = sift.extract(&g, &opts).expect("추출");
            times.push(t.elapsed().as_secs_f64() * 1e3);
            n = out.len();
        }
        let first = times[0];
        let mut rest = times[1..].to_vec();
        rest.sort_by(|a, b| a.total_cmp(b));
        println!("{name}: 특징 {n}, 첫 실행 {first:.1} ms, 이후 중앙값 {:.1} ms", rest[rest.len() / 2]);
    }
}

pub fn get(&self, x: usize, y: usize) -> u8

Value of pixel (x, y).

pub fn rotate_ccw(&self, k: u32) -> GrayImage

Counter-clockwise 90°xk rotation (matches the keypoint rotation transform: (x,y) -> (y, w-x)).

pub fn resized(&self, width: usize, height: usize) -> GrayImage

Resamples this image to (width, height) (Lanczos3, with anti-aliasing).

Examples found in repository

examples/bench_sift.rs (line 60)

fn main() {
    let args: Vec<String> = std::env::args().collect();
    let src = args.get(1).cloned().unwrap_or_else(|| "synthetic".into());
    let size: Option<(usize, usize)> = match (args.get(2), args.get(3)) {
        (Some(w), Some(h)) => Some((w.parse().expect("W"), h.parse().expect("H"))),
        _ => None,
    };
    let t = Instant::now();
    let mut g = if src == "synthetic" {
        let (w, h) = size.unwrap_or((2048, 1152));
        let mut s = 1u64;
        let mut noise = vec![0f32; w * h];
        for v in noise.iter_mut() {
            s = s.wrapping_mul(6364136223846793005).wrapping_add(1442695040888963407);
            *v = (s >> 40) as f32 / (1u64 << 24) as f32;
        }
        let mut out = vec![0f32; w * h];
        let mut tmp = vec![0f32; w * h];
        sift::pyramid::gaussian_blur(&noise, &mut out, &mut tmp, w, h, 2.0);
        GrayImage::from_f32(w, h, |x, y| (out[y * w + x] - 0.5) * 3.0 + 0.5)
    } else {
        read_gray(std::path::Path::new(&src)).expect("영상 읽기")
    };
    let t_read = t.elapsed();
    if let Some((w, h)) = size {
        if (w, h) != (g.width, g.height) {
            g = g.resized(w, h);
        }
    }
    println!("입력 {} ({}x{}), 읽기 {:.1} ms, 스레드 {}", src, g.width, g.height, t_read.as_secs_f64() * 1e3, rayon::current_num_threads());
    let sift = CpuSift::new();
    for (name, opts) in [("compat(기본)", SiftOptions::default()), ("무제한", SiftOptions { max_num_features: 0, ..Default::default() })]
    {
        let mut times = Vec::new();
        let mut n = 0;
        for _ in 0..5 {
            let t = Instant::now();
            let out = sift.extract(&g, &opts).expect("추출");
            times.push(t.elapsed().as_secs_f64() * 1e3);
            n = out.len();
        }
        let first = times[0];
        let mut rest = times[1..].to_vec();
        rest.sort_by(|a, b| a.total_cmp(b));
        println!("{name}: 특징 {n}, 첫 실행 {first:.1} ms, 이후 중앙값 {:.1} ms", rest[rest.len() / 2]);
    }
}

Trait Implementations

impl Clone for GrayImage

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for GrayImage

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for GrayImage

impl PartialEq for GrayImage

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for GrayImage