two calls to trigger the canvas update
          displayZone.imageData.data.set(displayZone.bmpArray);
          displayZone.ctx.putImageData(displayZone.imageData, 0, 0);
        }

        // On slider move...
        function update(quality) {
          // Call the WebAssembly function compress()
          // It will compress the bitmap image to Jpeg with given quality value.
          // Then it will decompress back and return the bitmap structure (width, height, uncompressedSize, data)
          let pI