BlurHash

use blurhash.qweruse blurhash_of, blurhash_data_url from blurhash      // Quillo 0.6: only these

blurhash = "0.2"image = { version = "0.25", default-features = false, features = ["jpeg", "png", "webp", "gif"] }base64 = "0.22"

// A photo that shows blurred until it has loaded.////   quillo run blurhash.qwe      then open http://localhost:8080/   (sample.jpg beside it)use "blurhash.qwer"let hash = blurhash_of("sample.jpg")?route GET /sample.jpg = file("sample.jpg")route GET /hash = { hash }route GET / = <html><body>    <img src="/sample.jpg" width="480" height="252" alt="The Quillo banner"         style={`background: url(${blurhash_data_url(hash, 32, 17)?}) center / cover`}/></body></html>

//! BlurHash placeholders: a photo as 20-odd characters that a page shows blurred while the real one loads.//! version: 1.0.0//!//! [dependencies]//! blurhash = "0.2"//! image = { version = "0.25", default-features = false, features = ["jpeg", "png", "webp", "gif"] }//! base64 = "0.22"use base64::engine::general_purpose::STANDARD;use base64::Engine;/// The BlurHash of the image at `path` (JPEG, PNG, WebP or GIF), with 4 by 3 components: store it beside the photo.pub fn blurhash_of(path: &str) -> Result<String, String> {    let img = image::open(path).map_err(|e| format!("{}: {}", path, e))?.thumbnail(64, 64).to_rgba8();    blurhash::encode(4, 3, img.width(), img.height(), img.as_raw()).map_err(|e| format!("{:?}", e))}/// A small PNG of a BlurHash, as a `data:` URL for an `<img>` or a CSS background: `width` by `height` pixels (32 by 32 is plenty; CSS scales it).pub fn blurhash_data_url(hash: &str, width: i64, height: i64) -> Result<String, String> {    let (w, h) = (width.clamp(4, 256) as u32, height.clamp(4, 256) as u32);    let pixels = blurhash::decode(hash, w, h, 1.0).map_err(|e| format!("{:?}", e))?;    let img = image::RgbaImage::from_raw(w, h, pixels).ok_or("the hash did not decode")?;    let mut png = std::io::Cursor::new(Vec::new());    img.write_to(&mut png, image::ImageFormat::Png).map_err(|e| e.to_string())?;    Ok(format!("data:image/png;base64,{}", STANDARD.encode(png.into_inner())))}