Automatically Colorize Face Photos

Introduction

Colors bring life to our photos and make them feel lively, exciting, or melancholic. The importance of color is twofold:

• It enables us to tell visual stories with our photos.

• It helps evoke emotions and create a mood for the viewers.

Objective

This lesson will show us how to use AI to colorize photos of faces. The face colorizer will convert our photos to a black and white format, then add natural and realistic colors to the detected faces. This lightweight colorizer, developed in Python and utilizing deep learning, will employ a pretrained Caffe model.

The colorization process involves the following steps:

Dependencies

We’ll be using the following external Python libraries.

Coding this utility

Let’s look at the main functions of this utility.

The load_colorization_model function

This function loads the pretrained colorization model. This model has been trained with the ImageNet dataset. Let’s take a look at this function.

• Lines 7–8 load the black and white colorizer model and the cluster center points.

• Line 10 sets the preferred backend of the neural network to CPU.

• Lines 13–18 add the cluster centers as 1 x 1 convolutions to the model. ...