Detecting barcodes in images

A barcode is a way that information is represented visually and is easy to understand for purpose-made machines. There are many barcode formats. The usual format has parallel vertical lines of different thicknesses and different amounts of space in between them.

In this section, we will demonstrate how to detect a simple parallel-lines formatted barcode from a still image. We will use the following image of a soda can:

Figure 11.6 – The original source image

1. Let's read the source image of a soda can using the following code:

   import numpy as np
   import cv2
   image=cv2.imread('/home/pi/book/dataset/barcode.jpeg', 1)
   input = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)

2. The horizontal image of a barcode has a low and a high vertical gradient. So, the candidate image must have the region that fits this criterion. We will use the cv2.Sobel() function to compute the horizontal and vertical derivatives and...