Python Machine Learning Cookbook - Second Edition

How to do it...

Let's see how to visualize the characters in an OCR database:

1. Create a new Python file, and import the following packages (the full code is given in the visualize_characters.py file that is provided to you):

import cv2 
import numpy as np 

2. Define the input file name:

# Load input data  
input_file = 'letter.data'  

3. Define visualization parameters:

# Define visualization parameters  
scaling_factor = 10 
start_index = 6 
end_index = -1 
h, w = 16, 8 

4. Keep looping through the file until the user presses the Escape key. Split the line into tab-separated characters:

# Loop until you encounter the Esc key with open(input_file, 'r') as f: for line in f.readlines(): data = np.array([255*float(x) for x in line.split('\t')[start_index:end_index]]) ...