Initial data commit

Task/Grayscale-image/JavaScript/grayscale-image.js

@@ -0,0 +1,23 @@
+function toGray(img) {
+  let cnv = document.getElementById("canvas");
+  let ctx = cnv.getContext('2d');
+  let imgW = img.width;
+  let imgH = img.height;
+  cnv.width = imgW;
+  cnv.height = imgH;
+
+  ctx.drawImage(img, 0, 0);
+  let pixels = ctx.getImageData(0, 0, imgW, imgH);
+  for (let y = 0; y < pixels.height; y ++) {
+    for (let x = 0; x < pixels.width; x ++) {
+      let i = (y * 4) * pixels.width + x * 4;
+      let avg = (pixels.data[i] + pixels.data[i + 1] + pixels.data[i + 2]) / 3;
+
+      pixels.data[i] = avg;
+      pixels.data[i + 1] = avg;
+      pixels.data[i + 2] = avg;
+    }
+  }
+  ctx.putImageData(pixels, 0, 0, 0, 0, pixels.width, pixels.height);
+  return cnv.toDataURL();
+}