why tesseract can't recognize the english words on this image?

Question

I am using tesseract 4.0 to recognize english words,but fail only on this image ,without any words been recognized,

any one can give a tip,thanks

    r=pytesseract.image_to_string('6.jpg', lang='eng')
    print(r)

Fail image

update:

I try to OCR with online website

https://www.newocr.com/

and it works,but why?

how can I use tesseract to recognize it?

Answer 1

The problem is pytesseract is not rotation-invariant. Therefore, you need to do additional pre-processing. source

• My first idea is to rotate the image with a small angle

• img = imutils.rotate_bound(cv2.imread("YD90o.png"), 4)
  

• Result:

  • 

• Now if I apply an adaptive-threshold

  • 

• To read with pytesseract you need to set additional configuration:

  • pytesseract.image_to_string(thr, lang="eng", config="--psm 6")
    

  • PSM (page-segmentation-mode) 6 is Assume a single uniform block of text. source

• Result:

  • You want to get the last sentence of the image.

  • txt = pytesseract.image_to_string(thr, lang="eng", config="--psm 6")
    txt = txt.replace('f', '').split('
    ')
    print(txt[len(txt)-2])
    

  • Result:

  • Continue Setub ie Gene
    

The website might use deep-learning method to detect the words in the image. But when I use newocr.com the result is:

oy Eee a
setuP me -
continve ae