Image Capture and OCR Apps for the iPhone

This is part of a series of blogs our Director, Alan Knue, has composed to help people increase their reading and writing efficiency

In this day and age when many current journals, magazines, newspapers, and books are available in electronic formats, the need for scanning and applying optical character recognition (OCR) to print material is becoming less and less. However, many older texts and references in libraries are still only available in printed form. Scanning pages from bound books is always problematic. It is difficult to get pages completely flat and when scanned and the text nearest to the binding is usually distorted. 

I hate having to bring my laptop and scanner with me to the library to scan pages from books, so I decided to test three popular and highly recommended image capture and/or OCR apps for the iPhone. These apps are generally designed to get a quick electronic version of printed materials, including hand written notes, but I thought they might be useful for scanning pages from books. The programs varied in intuitive design but all were generally easy to use after a short time.

General Observations

Flat pages worked well using all of the apps, but since I was interested in how these programs handled bound pages, I chose a page from a thick bound book printed in a serif font (similar to Times) and containing a variety of text styles including italicized text. As a comparison, I also scanned the same page using a flatbed scanner and used ClaroRead for its OCR capabilities to convert the page to an electronic document. The document produced using this method had nearly 99% accuracy. All of these apps were affected by lighting and caused some gradation of shadow across a page due to the lay of the open book. Sometimes the flash on the iPhone 4 helped and other times it created a tunnel effect with the text in the center being quite bright and crisp and the surrounding text gradually less distinct. The best results were accomplished when I could get a light in front of me to shine right on the page. But even in the best case scenario, the resulting jpg images, PDFs, and OCR-captured documents generated by these apps varied greatly.

App Review

Genius Scan (available in a free version and a $2.99 ad-free version with the option to upload files to Dropbox, EverNote, and GoogleDocs.). This app is only for scanning documents (no OCR) and was easy to use. Since it does not have an OCR, you need to have one available should you want to convert the image to electronic text. I used the program to scan a page from a book and email myself a jpeg and PDF version of the page. I then used ClaroRead on the 2 files to see how well it could recognize the text. I was never able to get a good enough image scan of a bound page for accurate OCR using this app and text recognition was always quite poor (at times nearly 0%).

Perfect OCR ($3.99). The app is easy and intuitive and there is good functionality for eliminating uneven lighting and shadows, improving the contrast, and reducing the effect of movement or jitter while using the camera. This app on its own produced electronic documents that were about 80% accurate in text recognition.

SayText (Free) actually got the best results of all at 90%+ accuracy. SayText utilizes the iPhone’s built in VoiceOver, so you can instantly have the OCR captured document read out loud. But SayText has no option for saving the documents on your iPhone which is a bit annoying but you can email the OCR captured text document to yourself. All of the other apps, have some document management for storing documents for access at a later date.

Of course, these 3 apps aren’t the only scanning apps one can find. There are several other options with similar functionality and more are added to the app library all the time. Most just take a picture of the document and convert it to a jpeg or PDF (like Genius Scan) whereas a few others include OCR for converting the picture of the document to electronic text (like Perfect OCR or SayText). All tested to date have produced similar results to the 3 described in this post. If you discover or know of a scanning app that you find does the trick, let me know!

Until that perfect scanning app comes along, I would use the free SayText to grab text and have it read out loud or to email it to myself for reference later. But for efficiency and accuracy, I won’t be abandoning my trusty scanner and ClaroRead anytime soon.

To try on these apps and others on an iPod or iPhone contact our AT Specialists for a demonstration of the available options.