visionapi_sample_1.js

var gcloud = require('gcloud')({
  keyFilename: '/path/to/keyfile.json',
  projectId: '<YOUR-PROJECT-HERE>'
});
var vision = gcloud.vision();

var image = 'image.jpg';

vision.detectText('image.jpg', function(err, text, apiResponse) {
  // text = ['This was text found in the image']
});

I did in this way:

const fullTextAnnotation = response[0].fullTextAnnotation;
console.log(fullTextAnnotation.text);

Check this: https://stackoverflow.com/questions/47641619/image-detection-with-google-vison-and-nodejs/47657567#47657567