Recognize a number from an image

Question

I\'m trying to write an application to find the numbers inside an image and add them up.

How can I identify the written number in an image?

Answer 1

I would recommend to combine 2 basic neural network components:

• Perceptron
• Self Organized Map (SOM)

A perceptron is a very simple neural network component. It takes multiple inputs and produces 1 output. You need to train it by feeding it both inputs and outputs. It's a self learning component.

Internally it has a collection of weight factors, which are used to calculate the output. These weight factors are perfected during training. The beautiful thing about a perceptron is that, (with a proper training) it can handle data that it has never seen before.

You can make a perceptron more powerful by arranging it in a multi-layer network, meaning that the output of one perceptron acts as the input of another perceptron.

In your case you should use 10 perceptron networks, one for each numeric value (0-9).

But in order to use perceptrons you will need an array of numeric inputs. So first you need something to convert you visual image to numeric values. A Self Organized Map (SOM) uses a grid of inter-connected points. The points should be attracted to the pixels of your image (See below)

The 2 components work well together. The SOM has a fixed number of grid-nodes, and your perceptron needs a fixed number of inputs.

Both components are really popular and are available in educational software packages such as MATLAB.

UPDATE: 06/01/2018 - Tensor Flow

This video tutorial demonstrates how it can be done in python using Google's TensorFlow framework. (click here for a written tutorial).