From the website:
Project Naptha
Project Naptha automatically applies state-of-the-art computer vision algorithms on every image you see while browsing the web. The result is a seamless and intuitive experience, where you can highlight as well as copy and paste and even edit and translate the text formerly trapped within an image.
Doesn't work with Internet Explorer -- Google Chrome is the browser of choice.
It takes a screen-cap or a photograph with embedded text, performs Optical Character Recognition and allows you to copy and paste the text.
It also allows you to re-write the text back into the image and there is the option to pipe the results through Google Translate.
To install, you visit the website while using Google Chrome. There will be a big button for adding it. As simple as can be. A few rough edges but an incredible solution to a long-standing problem...