Merge pull request #9 from Schmiddiii/image

Integration with image crate

Cargo.toml

@@ -11,11 +11,16 @@ authors = ["Raincal <cyj94228@gmail.com>"]
 edition = "2018"
 
 [dependencies]
+image = { version = "0.23", optional = true }
 
 [dev-dependencies]
 image = "0.23"
 criterion = "0.5"
 
+[features]
+default = []
+image = [ "dep:image" ]
+
 [[bench]]
 name = "decode"
 harness = false

src/lib.rs

@@ -223,9 +223,44 @@ fn components(blurhash: &str) -> Result<(usize, usize), Error> {
  Ok((num_x, num_y))
 }
 
+/// Calculates the blurhash for an [DynamicImage][image::DynamicImage] using the given x and y component counts.
+#[cfg(feature = "image")]
+pub fn encode_image(
+ components_x: u32,
+ components_y: u32,
+ image: &image::RgbaImage,
+) -> Result<String, Error> {
+ use image::EncodableLayout;
+ encode(
+ components_x,
+ components_y,
+ image.width(),
+ image.height(),
+ image.as_bytes(),
+ )
+}
+
+/// Decodes the given blurhash to an image of the specified size.
+///
+/// The punch parameter can be used to de- or increase the contrast of the
+/// resulting image.
+#[cfg(feature = "image")]
+pub fn decode_image(
+ blurhash: &str,
+ width: u32,
+ height: u32,
+ punch: f32,
+) -> Result<image::RgbaImage, Error> {
+ let bytes = decode(blurhash, width, height, punch)?;
+ // Save to unwrap as `decode` (if successfull) always returns a buffer of size `4 * width * height`, which is exactly
+ // the amount of bytes required to construct the `RgbaImage`.
+ let buffer = image::RgbaImage::from_raw(width, height, bytes).expect("decoded image too small");
+ Ok(buffer)
+}
+
 #[cfg(test)]
 mod tests {
- use super::{decode, encode};
+ use super::*;
  use image::{save_buffer, ColorType::Rgba8};
  use image::{EncodableLayout, GenericImageView};
 
@@ -252,4 +287,26 @@ mod tests {
  // assert_eq!(blurhash, "LFL4=pI8%foujXofRkWC.loyH?V{");
  assert_eq!(blurhash, "LNAdAqj[00aymkj[TKay9}ay-Sj[");
  }
+
+ #[test]
+ #[cfg(feature = "image")]
+ fn test_jelly_beans_image() {
+ let img = image::open("data/octocat.png").unwrap();
+
+ let blurhash = encode_image(4, 3, &img.to_rgba8()).unwrap();
+
+ assert_eq!(blurhash, "LNAdAqj[00aymkj[TKay9}ay-Sj[");
+ }
+
+ #[test]
+ #[cfg(feature = "image")]
+ fn decode_blurhash_image() {
+ let img = image::open("data/octocat.png").unwrap();
+ let (width, height) = img.dimensions();
+
+ let blurhash = encode_image(4, 3, &img.to_rgba8()).unwrap();
+ let img = decode_image(&blurhash, width, height, 1.0).unwrap();
+
+ assert_eq!(img.as_bytes()[0..5], [1, 1, 1, 255, 1]);
+ }
 }