refine

README.md

@@ -16,7 +16,110 @@ The code for `Node.js` and `Deno` is generated using `wit-bindgen` and `jco`.
 | --------------- |---------------| -------------------- |
 | ![](https://github.com/bokuweb/pixelmatch-rs/raw/main/fixtures/001a.png) | ![](https://github.com/bokuweb/pixelmatch-rs/raw/main/fixtures/001b.png) |![](https://github.com/bokuweb/pixelmatch-rs/raw/main/assets/diff1.png)|
 
-## Generate JS code from wasm component.
+## JavaScript
+
+
+### installation
+
+```
+npm install @bokuweb/image-diff-wasm
+```
+
+### examples
+
+```js
+import { readFile } from "node:fs/promises";
+import { diff } from "@bokuweb/image-diff-wasm";
+
+const imga = await readFile(PATH_TO_IMAGE_A);
+const imgb = await readFile(PATH_TO_IMAGE_B);
+
+const result = diff(imga, imgb, { enableAntiAlias: true, threshold: 0.01 });
+```
+
+### API
+
+#### diff(imga: Uint8Array, imgb: Uint8Array, opts: Opts): Output;
+
+The diff function is designed to compare two images and identify their differences.
+It takes two image buffers as input and returns an `Output` object containing information about the differences.
+
+##### Input
+
+- `imga`: Uint8Array: The first image buffer.
+- `imgb`: Uint8Array: The second image buffer.
+- `opts`: Opts: Options object for the function.
+
+```Typescript
+export interface Opts {
+  threshold?: number,
+  includeAntiAlias?: boolean,
+}
+```
+
+- `threshold`: Matching threshold, ranges from 0 to 1. Smaller values make the comparison more sensitive. 0.1 by default.
+- `includeAntiAlias`: The flag of antialias. If omitted false.
+
+##### Output
+
+```Typescript
+export interface Output {
+  diffCount: number,
+  diffImage: Uint8Array,
+  width: number,
+  height: number,
+}
+```
+
+- `diffCount`: The number of pixels that differ between the two images.
+- `diffImage`: The buffer of the difference image in `WebP` format.
+- `width`: The width of the difference image.
+- `height`: The height of the difference image.
+
+##### Error
+
+The function may throw following values as `ComponentError`.
+
+```Typescript
+export type Error = ErrorDecode | ErrorEncode;
+export interface ErrorDecode {
+  tag: 'decode',
+  val: string,
+}
+export interface ErrorEncode {
+  tag: 'encode',
+  val: string,
+}
+```
+
+## Rust
+
+### examples
+
+```Rust
+pub fn main() {
+    let imga = std::fs::read("../fixtures/sample0.webp").unwrap();
+    let imgb = std::fs::read("../fixtures/sample1.webp").unwrap();
+
+    let _result = diff(
+        imga,
+        imgb,
+        &DiffOption {
+            threshold: Some(0.01),
+            include_anti_alias: Some(true),
+        },
+    )
+    .unwrap();
+}
+```
+
+``` sh
+cargo run --example compare
+```
+
+## Wasm
+
+### Generate JS code from wasm component.
 
 ```sh
 AR=llvm-ar CFLAGS='--sysroot ../wasi-sdk/share/wasi-sysroot' cargo wasi build --release

wasm/src/lib.rs

@@ -7,7 +7,10 @@ wit_bindgen::generate!({
  }
 });
 
-struct ImageDiff;
+// re-export
+pub use image_diff_rs::diff;
+
+pub struct ImageDiff;
 
 impl From<ImageDiffError> for bokuweb::image_diff::types::Error {
     fn from(value: ImageDiffError) -> Self {