How to Build Deep Learning Models for Font Classification with Tensorflow: CNN, Deeper CNN, Hidden Layers Models

You will learn how to build and train decent deep learning models for classification problem with a few lines of code in TensorFlow. The 5 models covered in this article are:

  • Logistic regression model
  • The single hidden layer model
  • Multiple hidden layers model
  • Deep CNN with convolutional layer and pooling layer
  • Deeper CNN with 2 convolutional layers and 2 pooling layers

The following methods have been used for achieving better performance in this project:

  • Gradient descent optimizer
  • RELU activation function
  • Learning rate decay
  • One hot encoding
  • Cross entropy
  • Dropout

There are images of letters in fonts Sans Serif and Serif. The goal is to identify fonts based on one specific image of a single letter. It is a straightforward classification problem.

2 types of fonts

Data engineering

  1. Convert images to grayscale with 36*36 pixels
  2. Add labels to dataset: font SansSerif = 0, font Serif = 1
  3. Shuffle and split the dataset into 2 datasets: train dataset (80%) and test dataset (20%)
train dataset and test dataset

Logistic regression model

  1. Model specification
Logistic regression model

2. Model training

Logistic regression model trainning

Train accuracy: 0.718935

Test accuracy: 0.692913


Single hidden layer model

  1. Model specification
Single hidden layer model

2. Model training

Single hidden layer model trainning
confusion matrix

Multiple hidden layers model

  1. Model specification
Multiple hidden layers model

2. Model training

Multiple hidden layers model training

Deep CNN with convolutional layer and pooling layer

  1. Model specification
Deep CNN

2. Model training

Deep CNN training

Deeper CNN with 2 convolutional layers and 2 pooling layers

  1. Model specification
Deeper CNN

2. Model training

Deeper CNN training

Summary

Congrats! You just learn how to build and train 5 deep learning models for classification problems using Tensorflow.

One more thing about adding pooling layer is that because of the pooling, the image size is gradually shrinking. Early convolutional weights often train to detect simple edges, while successive convolutional layers combine those edges into gradually more complex shapes such as faces, cars, and even dogs.

Human learning is the beginning of Deep learning! Have fun.