(Disclaimer: I work for creatale GmbH)

We open-sourced the library that we use for exactly that purpose: https://github.com/creatale/node-fv

(Disclaimer: I work for creatale GmbH)

As you mentioned ocrad.js I assume you search for something in js/nodejs. Many others already recommended tesseract and OpenCV. We have built a library around tesseract for character recognition and OpenCV (and other libraries) for preprocessing, all for node.js/io.js: https://github.com/creatale/node-dv

If you have to recognize forms or other structured images, we also created a higher-level library: https://github.com/creatale/node-fv

I can attest to this. I used Node-DV in a production environment and it's pretty damn amazing with all its built-in functionality.

There are options to adjust the image in various ways and once Tesseract runs, it's easy to get the result in various formats.