Rewrite part of src/common/work.js

src/common/worker.js

@@ -1,3 +1,4 @@
+const readImage = require('tesseract.js-core/src/utils/readImage');
 var latestJob,
     Module,
     base,
@@ -69,14 +70,11 @@ function handleInit(req, res){
 }
 
 function setImage(Module, base, image) {
-  const imgbin = desaturate(image);
-  const { width, height } = image;
-
-  const ptr = Module._malloc(imgbin.length, Uint8Array.BYTES_PER_ELEMENT);
-  Module.HEAPU8.set(imgbin, ptr);
-  base.SetImage(ptr, width, height, Uint8Array.BYTES_PER_ELEMENT, width);
-  base.SetRectangle(0, 0, width, height);
-  return ptr;
+  const { w, h, data } = readImage(Module, Array.from(image));
+
+  base.SetImage(data);
+  base.SetRectangle(0, 0, w, h);
+  return data;
 }
 
 function loadLanguage(req, res, cb){

src/node/index.js

@@ -1,70 +1,19 @@
-const check = require('check-types');
+const util = require('util');
+const fs = require('fs');
 const fetch = require('isomorphic-fetch');
 const isURL = require('is-url');
 const { fork } = require('child_process');
-const fs = require('fs');
 const path = require('path');
-const fileType = require('file-type');
-const PNGReader = require('png.js');
-const JPGReader = require('jpeg-js');
-
-function loadImage(image, cb) {
-  if (check.string(image)) {
-    if (isURL(image)) {
-      fetch(image)
-        .then(resp => resp.buffer())
-        .then(buffer => loadImage(buffer, cb))
-        .catch(err => console.error(err));
-    } else {
-      fs.readFile(image, (err, buffer) => {
-        if (err) throw err;
-        loadImage(buffer, cb);
-      });
-    }
-    return;
-  }
-  if (image instanceof Buffer) {
-    const { mime } = fileType(image);
-
-    if (mime === 'image/png') {
-      const reader = new PNGReader(image);
-      reader.parse((err, png) => {
-        if (err) throw err;
-
-        const width = png.getWidth();
-        const height = png.getHeight();
-        const data = new Uint8Array(width * height * 4);
 
-        for (let j = 0; j < height; j += 1) {
-          for (let i = 0; i < width; i += 1) {
-            const offset = 4 * (i + (j * width));
-            const pix = png.getPixel(i, j);
+const readFile = util.promisify(fs.readFile);
 
-            Array(4).fill(0).forEach((v, idx) => {
-              data[offset + idx] = pix[idx];
-            });
-          }
-        }
-        loadImage({ width, height, data }, cb);
-      });
-      return;
-    }
-    if (mime === 'image/jpeg') {
-      loadImage(JPGReader.decode(image), cb);
-      return;
-    }
-
-    // TODO: support for TIFF, NetPBM, BMP, etc.
-  }
-
-  // node uses json.stringify for ipc which means we need to turn
-  // fancy arrays into raw arrays
-  if (image && image.data && image.data.length && !Array.isArray(image.data)) {
-    loadImage({ ...image, data: Array.from(image.data) }, cb);
-    return;
+const loadImage = (imageURI) => {
+  if (isURL(imageURI)) {
+    return fetch(imageURI)
+      .then(resp => resp.buffer());
   }
-  cb(image);
-}
+  return readFile(imageURI);
+};
 
 exports.defaultOptions = {
   workerPath: path.join(__dirname, 'worker.js'),
@@ -84,13 +33,15 @@ exports.terminateWorker = (instance) => {
 };
 
 exports.sendPacket = (instance, packet) => {
-  loadImage(packet.payload.image, (img) => {
-    instance.worker.send({
-      ...packet,
-      payload: {
-        ...packet.payload,
-        image: img,
-      },
+  loadImage(packet.payload.image)
+    .then(buf => new Uint8Array(buf))
+    .then((img) => {
+      instance.worker.send({
+        ...packet,
+        payload: {
+          ...packet.payload,
+          image: Array.from(img),
+        },
+      });
     });
-  });
 };