As per my question on StackOverflow: PyTesseract not recognizing decimals
<https://stackoverflow.com/questions/64203559/pytesseract-not-recognizing-decimals>
I'm using PyTesseract to recognise text in table cells. When it comes to
recognising drug doses with decimal points, the OCR fails to recognise the
period character ( . ) , though is accurate for everything else. I'm
using tesseract v5.0.0-alpha.20200328 on Windows 10.
My pre-processing consists of upscaling by 400% using cubic, conversion to
black and white, dilation and erosion, morphology, and blurring. I've tried
a decent combination of all of these (as well as each on their own), and
nothing has recognized the .
I've tried --psm of various values as well as a character whitelist. I
believe the font is Sergoe UI.
Before processing: [image: S87rd.png] <https://i.stack.imgur.com/S87rd.png>
After processing: [image: OFjoL.png] <https://i.stack.imgur.com/OFjoL.png>
PyTesseract output: 25mg »p
Processing code attached
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import cv2, pytesseract
import numpy as np
image = cv2.imread( '01.png' )
upscaled_image = cv2.resize(image, None, fx = 4, fy = 4, interpolation =
cv2.INTER_CUBIC)
bw_image = cv2.cvtColor(upscaled_image, cv2.COLOR_BGR2GRAY)
kernel = np.ones((2, 2), np.uint8)
dilated_image = cv2.dilate(bw_image, kernel, iterations=1)
eroded_image = cv2.erode(dilated_image, kernel, iterations=1)
thresh = cv2.threshold(eroded_image, 205, 255, cv2.THRESH_BINARY)[1]
kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (3, 3))
morh_image = cv2.morphologyEx(thresh, cv2.MORPH_CLOSE, kernel)
blur_image = cv2.threshold(cv2.bilateralFilter(morh_image, 5, 75, 75), 0, 255,
cv2.THRESH_BINARY + cv2.THRESH_OTSU)[1]
final_image = blur_image
text = pytesseract.image_to_string(final_image, lang='eng', config='--psm 10')
