Merge pull request #10 from akx/improvements

Small improvements

Author: hschimke

src/encode_hints.rs

@@ -1,5 +1,5 @@
 use rxing::{datamatrix::encoder::SymbolShapeHint, Dimension};
-use std::collections::{HashMap, HashSet};
+use std::collections::{HashMap};
 use wasm_bindgen::prelude::*;
 
 #[wasm_bindgen]

src/lib.rs

@@ -325,7 +325,7 @@ pub fn decode_barcode(
 /// Such an object could be obtained using the `getImageData`
 /// method of a `CanvasRenderingContext2D` object.
 pub fn convert_js_image_to_luma(data: &[u8]) -> Vec<u8> {
-    let mut luma_data = Vec::new();
+    let mut luma_data = Vec::with_capacity(data.len() / 4);
     for src_pixel in data.chunks_exact(4) {
         let [red, green, blue, alpha] = src_pixel else {
             continue;