1. Optical Character Recognition
Mobile App. Development Project
Aakanksha Gupta

2. Optical Character Recognition
A Technology that enables one to extract text out of printed documents, captured images
Targets typewritten text, one character at a time
An "offline" process, which analyses a static document
Pre-Processes images for successful recognition
Android currently doesn’t come pre bundled with libraries for OCR, hence need external libraries
Current Apps on Google Play Store:
Google Keep
Text Fairy
CamScanner
Application in Real Life
Data entry for business documents, e.g. check, passport
Extracting business card information into a contact list
Converting handwriting in real time to control a compute

3. Text Recognition Functionality: An app developed to allow user to
capture an image and gives user
an option to see the text what is available on
the image. Images are not stored but gives
an option to store in external media.
Requirement: Android 5 and above
Features: Camera Feature, Convert English Words to Text
Issues: Sometimes gives garbage values and cannot recognise text
Camera gives blur images sometimes
Horizontal and Vertical camera orientation
Autofocusing

4. Demo of Text Recognition

5. Implementation Preparing Tesseract
Tesseract has unicode (UTF-8) support,
and can recognize more than 100 languages
It provides API for converting Image to Text.
Used English Language for the application
Install Native Development Kit (NDK) is a set
of tools that allows you to use C and C++ code
to run in Java and Android
Methodology
Adding tess-two library to dependency
Creating a class to manage Tesseract calls
Initialize the object and call methods on the object

6. Android Side Using OpenCV 3_1_0
Still have to take a photo from the camera,
Loading data from image files
Gradle

7. Initialize the TessBAseAPI with the path to traineddata file and proper page segmentation
Pass the image as bitmap to tessBaseAPI variable
Call getUTF8Text method, and this will return string value

8. CameraBridgeViewBase
Implemented to control when camera can be enabled, process the frame, calls external listener to make adjustment to frame
Bitmap
Graphic image file used to store digital images, 32 bit color
FloatingActionButton
Circled icon floating above the UI

9. Enable the Tesseract
Toast notifications, and all the other notifications

10. Layout and Resource

11. AndroidManifest.xml
Uses External Memory
Change the icon of the application
Change the name of application
Uses the UTF-8 character encoding
which is capable of encoding all
possible characters defined by Unicode

12. Challenges Improvement
Choosing the dataset was the biggest challenge
Tried with Matalab but results were not fine
Working with Tesseract
Installing NDK and making it work
Improvement
Tesseract dataset is not great, sometimes give garbage values instead of detection
Camera orientation creates issue
Image when stored for processing appears to be blurred
Not 100% accurate

13. Learnings Learned a lot about OpenCV & Tesseract
Why dataset are important
Android layout can be fun
Not always does internet helps
And yes, Finally I made an App of my own!! Phew.

14. Questions??