Blurry_Barcode.md

Read Blurry Barcode in Python

This answer for this Question in StackOverflow.

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How to Read Blurry Barcode in Python

Theory: The barcode consists of vertical black zone to represent each bar, so I did the summation of the rows, and thresholded the whole image depending on an empirical value near the mean of the summation.

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Python Code

#========================
# Import Libraies
#========================
import numpy as np
import cv2 as cv
import matplotlib.pyplot as plt 
from pyzbar import pyzbar

#------------------------
# Read Image
#========================
img = cv.imread('barcode_example.jpg', cv.IMREAD_GRAYSCALE)

# #------------------------
# # Morphology
# #========================
# # Closing
# #------------------------
closed = cv.morphologyEx(img, cv.MORPH_CLOSE, cv.getStructuringElement(cv.MORPH_RECT, (1, 21)))

# #------------------------
# # Statistics
# #========================
print(img.shape)
dens = np.sum(img, axis=0)
mean = np.mean(dens)
print(mean)

#------------------------
# Thresholding
#========================
thresh = closed.copy()
for idx, val in enumerate(dens):
    if val< 10800:
        thresh[:,idx] = 0

(_, thresh2) = cv.threshold(thresh, 128, 255, cv.THRESH_BINARY + cv.THRESH_OTSU)

#------------------------
# plotting the results
#========================
plt.figure(num='barcode')

plt.subplot(221)
plt.imshow(img, cmap='gray')
plt.title('Original')
plt.axis('off')

plt.subplot(224)
plt.imshow(thresh, cmap='gray')
plt.title('Thresholded')
plt.axis('off')

plt.subplot(223)
plt.imshow(thresh2, cmap='gray')
plt.title('Result')
plt.axis('off')

plt.subplot(222)
plt.hist(dens)
plt.axvline(dens.mean(), color='k', linestyle='dashed', linewidth=1)
plt.title('dens hist')

plt.show()

#------------------------
# Printing the Output
#========================
barcodes = pyzbar.decode(thresh2)
print(barcodes)

Result

Output:

[Decoded(data=b'00004980072868003004',
 type='CODE128',
 rect=Rect(left=34, top=0, width=526, height=99),
  polygon=[Point(x=34, y=1), Point(x=34, y=99),
   Point(x=560, y=98), Point(x=560, y=0)])]