I want to extract the text from an image in python
. In order to do that, I have chosen pytesseract
. When I tried extracting the text from the image, the results weren't satisfactory. I also went through this and implemented all the techniques listed down. Yet, it doesn't seem to perform well.
Image:
Code:
import pytesseract
import cv2
import numpy as np
img = cv2.imread('D:\\wordsimg.png')
img = cv2.resize(img, None, fx=1.2, fy=1.2, interpolation=cv2.INTER_CUBIC)
img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
kernel = np.ones((1,1), np.uint8)
img = cv2.dilate(img, kernel, iterations=1)
img = cv2.erode(img, kernel, iterations=1)
img = cv2.threshold(cv2.medianBlur(img, 3), 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)[1]
pytesseract.pytesseract.tesseract_cmd = 'C:\\Program Files\\Tesseract-OCR\\tesseract.exe'
txt = pytesseract.image_to_string(img ,lang = 'eng')
txt = txt[:-1]
txt = txt.replace('\n',' ')
print(txt)
Output:
t hose he large form might light another us should took mountai house n story important went own own thought girl over family look some much ask the under why miss point make mile grow do own school was
Even 1 unwanted space could cost me a lot. I want the results to be 100% accurate. Any help would be appreciated. Thanks!
I changed resize from 1.2 to 2 and removed all preprocessing. I got good results with psm 11 and psm 12
import pytesseract
import cv2
import numpy as np
img = cv2.imread('wavy.png')
# img = cv2.resize(img, None, fx=1.2, fy=1.2, interpolation=cv2.INTER_CUBIC)
img = cv2.resize(img, None, fx=2, fy=2)
img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
kernel = np.ones((1,1), np.uint8)
# img = cv2.dilate(img, kernel, iterations=1)
# img = cv2.erode(img, kernel, iterations=1)
# img = cv2.threshold(cv2.medianBlur(img, 3), 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)[1]
cv2.imwrite('thresh.png', img)
pytesseract.pytesseract.tesseract_cmd = 'C:\\Program Files (x86)\\Tesseract-OCR\\tesseract.exe'
for psm in range(6,13+1):
config = '--oem 3 --psm %d' % psm
txt = pytesseract.image_to_string(img, config = config, lang='eng')
print('psm ', psm, ':',txt)
The config = '--oem 3 --psm %d' % psm
line uses the string interpolation (%) operator to replace %d
with an integer (psm). I'm not exactly sure what oem
does, but I've gotten in the habit of using it. More on psm
at the end of this answer.
psm 11 : those he large form might light another us should name
took mountain story important went own own thought girl
over family look some much ask the under why miss point
make mile grow do own school was
psm 12 : those he large form might light another us should name
took mountain story important went own own thought girl
over family look some much ask the under why miss point
make mile grow do own school was
psm
is short for page segmentation mode. I'm not exactly sure what the different modes are. You can get a feel for what the codes are from the descriptions. You can get the list from tesseract --help-psm
Page segmentation modes:
0 Orientation and script detection (OSD) only.
1 Automatic page segmentation with OSD.
2 Automatic page segmentation, but no OSD, or OCR. (not implemented)
3 Fully automatic page segmentation, but no OSD. (Default)
4 Assume a single column of text of variable sizes.
5 Assume a single uniform block of vertically aligned text.
6 Assume a single uniform block of text.
7 Treat the image as a single text line.
8 Treat the image as a single word.
9 Treat the image as a single word in a circle.
10 Treat the image as a single character.
11 Sparse text. Find as much text as possible in no particular order.
12 Sparse text with OSD.
13 Raw line. Treat the image as a single text line,
bypassing hacks that are Tesseract-specific.