feat: add base64 string encoding

Author: EscapedGibbon

src/save/encodeBase64.ts

@@ -0,0 +1,52 @@
+
+import type { Image } from '../Image.js';
+
+import {encode} from './encode.js';
+import type {ImageFormat} from './encode.js';
+
+
+/**
+ * Converts image into a base64 URL string.
+ * @param image - Image to get base64 encoding from.
+ * @param format - Image format.
+ * @returns base64 string.
+ */
+export function encodeBase64(image:Image,format:ImageFormat){
+  const isNode = typeof window === 'undefined' && typeof document === 'undefined';
+  if(isNode){
+    return encodeBase64InNode(image,format);
+  }else{
+    return encodeBase64InBrowser(image,format);
+  }
+}
+
+
+/**
+ * Converts image into a base64 URL string in NodeJs.
+ * @param image - Image to get base64 encoding from.
+ * @param format - Image format.
+ * @returns base64 string.
+ */
+function encodeBase64InNode(image:Image,format:ImageFormat){
+  const encodedData = encode(image,{format});
+  return `data:image/${format};base64,${(Buffer.from(encodedData)
+    .toString('base64'))}`
+}
+/**
+ *  Converts image into a base64 URL string in browser.
+ * @param image - Image to get base64 encoding from.
+ * @param format - Image format.
+ * @returns base64 string.
+ */
+function encodeBase64InBrowser(image:Image,format:ImageFormat){
+  const buffer = encode(image,{format});  
+  let binaryString = '';
+  for(const el of buffer){
+    binaryString += String.fromCodePoint(el);
+  }
+  const base64String = btoa(binaryString);
+  const dataURL = `data:image/${format};base64,${base64String}`; 
+ return dataURL;
+}
+
+

src/save/index.ts

@@ -3,3 +3,4 @@ export * from './encodePng.js';
 export * from './encodeJpeg.js';
 export * from './write.js';
 export * from './writeCanvas.js';
+export * from './encodeBase64.js';