client/src/App.tsx

@@ -12,17 +12,18 @@ enum AppState {
 }
 
 function App() {
-  const [baseImage, setBaseImage] = React.useState<Uint8ClampedArray>();
+  const [baseImage, setBaseImage] = React.useState<Blob>();
-  const [ditheredImage, setDitheredImage] = React.useState<Uint8ClampedArray>();
+  const [ditheredImage, setDitheredImage] = React.useState<Blob>();
   const [appState, setAppState] = React.useState<AppState>(AppState.NO_IMAGE);
 
-  const handleImageSubmit = async (data: Uint8ClampedArray) => {
+  const handleImageSubmit = async (data: Blob) => {
     setBaseImage(data);
     setAppState(AppState.IMAGE_LOADED);
 
     try {
-      const ditheredImage = await new Ditherer().dither(data);
+      const imageArray = new Uint8ClampedArray(await data.arrayBuffer());
-      setDitheredImage(ditheredImage);
+      const ditheredImage = await new Ditherer().dither(imageArray);
+      setDitheredImage(new Blob([ditheredImage], { type: "image/png" }));
       setAppState(AppState.IMAGE_PROCESSED);
     } catch (e) {
       console.error(e);
@@ -50,11 +51,11 @@ function App() {
           </p>
         </article>
         <ImageInput onImageSubmit={handleImageSubmit}></ImageInput>
-        {appState === AppState.IMAGE_LOADED && (
+        {appState === AppState.IMAGE_LOADED && baseImage && (
-          <ImagePreview imageData={baseImage as Uint8ClampedArray} />
+          <ImagePreview imageData={baseImage} />
         )}
-        {appState === AppState.IMAGE_PROCESSED && (
+        {appState === AppState.IMAGE_PROCESSED && ditheredImage && (
-          <ImageOutput imageData={ditheredImage as Uint8ClampedArray} />
+          <ImageOutput imageData={ditheredImage} />
         )}
       </main>
     </div>

client/src/ImageInput.tsx

@@ -1,11 +1,10 @@
 import React, { FormEventHandler } from "react";
 
 interface Props {
-  onImageSubmit: (image: Uint8ClampedArray) => void;
+  onImageSubmit: (image: Blob) => void;
 }
 
 function ImageInput({ onImageSubmit }: Props) {
-  let fileReader: FileReader;
   const fileInputRef = React.useRef<HTMLInputElement>(null);
 
   const handleSubmit: FormEventHandler = (e) => {
@@ -18,16 +17,7 @@ function ImageInput({ onImageSubmit }: Props) {
       return;
     }
 
-    fileReader = new FileReader();
+    onImageSubmit(fileInputRef.current.files[0]);
-    fileReader.onloadend = handleFileRead;
-    fileReader.readAsArrayBuffer(fileInputRef.current.files[0]);
-  };
-
-  const handleFileRead: EventListener = (e) => {
-    if (fileReader.result) {
-      const image = new Uint8ClampedArray(fileReader.result as ArrayBuffer);
-      onImageSubmit(image);
-    }
   };
 
   return (

client/src/ImageOutput.tsx

@@ -1,16 +1,23 @@
 import FileSaver from "file-saver";
+import { useEffect } from "react";
 import "./ImageOutput.css";
 
 interface OutputProps {
-  imageData: Uint8ClampedArray;
+  imageData: Blob;
 }
 
 function ImageOutput({ imageData }: OutputProps) {
-  const imageBlob = new Blob([imageData], { type: "image/png" });
+  const imageUrl = URL.createObjectURL(imageData);
-  const imageUrl = URL.createObjectURL(imageBlob);
+
+  useEffect(() => { 
+    return () => { 
+      URL.revokeObjectURL(imageUrl);
+    }
+  }, [imageUrl]);
 
   const handleClick = () => {
-    FileSaver.saveAs(imageBlob, "image.png");
+    const extension = imageData.type.split("/")[1];
+    FileSaver.saveAs(imageData, `image.${extension}`);
   };
 
   return (

client/src/ImagePreview.tsx

@@ -1,10 +1,17 @@
+import { useEffect } from "react";
+
 interface ImagePreviewProps {
-  imageData: Uint8ClampedArray;
+  imageData: Blob;
 }
 
 function ImagePreview({ imageData }: ImagePreviewProps) {
-  const imageBlob = new Blob([imageData], { type: "image/png" });
+  const imageUrl = URL.createObjectURL(imageData);
-  const imageUrl = URL.createObjectURL(imageBlob);
+
+  useEffect(() => { 
+    return () => { 
+      URL.revokeObjectURL(imageUrl);
+    }
+  }, [imageUrl]);
 
   return (
     <div className="blur-sm mx-auto">