Can't load tiff image from readImage(buffer)

[fiefdx]

Describe the bug

const fs = require('fs');
const path = require('path');

const cv = require("opencv");

const sourcePath = "./test.tiff";
const targetPath = "./test.jpg";

console.log("before image resize");

let content = fs.readFileSync(sourcePath);
console.log(`content type: ${content instanceof Buffer}`);

cv.readImage(content, function(err, mat) {
    mat.resize(640, 360);
    // mat.save(targetPath);
    let buf = mat.toBuffer({ext: ".jpg", jpegQuality: 100});
    var targetFile = fs.openSync(targetPath, "w");
        fs.writeFileSync(targetFile, buf, {encoding: 'binary', flag: 'w'});
        fs.closeSync(targetFile);
    console.log("convert image");
});

console.log("after image resize");

breeze@breeze-desktop:~/Work/uber-test/xviz/examples/data-server$ nodejs ./opencv-tiff2jpeg.js 
before image resize
content type: true
OpenCV Error: Unspecified error (failed to write image data to temporary file) in imdecode_, file /home/breeze/Work/data/vehicle_data/impl-ros-kinetic/script/tmp/opencv-3.3.0/modules/imgcodecs/src/loadsave.cpp, line 657
/home/breeze/Work/uber-test/xviz/examples/data-server/opencv-tiff2jpeg.js:15
    mat.resize(640, 360);
        ^

TypeError: Cannot read property 'resize' of null
    at /home/breeze/Work/uber-test/xviz/examples/data-server/opencv-tiff2jpeg.js:15:6
    at Object.<anonymous> (/home/breeze/Work/uber-test/xviz/examples/data-server/opencv-tiff2jpeg.js:14:4)
    at Module._compile (module.js:653:30)
    at Object.Module._extensions..js (module.js:664:10)
    at Module.load (module.js:566:32)
    at tryModuleLoad (module.js:506:12)
    at Function.Module._load (module.js:498:3)
    at Function.Module.runMain (module.js:694:10)
    at startup (bootstrap_node.js:204:16)
    at bootstrap_node.js:625:3

OS / Libraries

• Ubuntu 16.04