Problem with hack challenge

Hi everyone!

What happens

I’m working on a hacking challenge and I’m stuck. The challenge is to solve in one minute 45 of 50 (90%) captchas that are distorted.

What do you understand or find about that problem

I must manipulate the image to reduce the distortion generated by the captcha.

You make any workaround? What did you do?

I am using tesseract and pytesseract for OCR and imagemagick for image processing, all this with python.

(Optional) Why fails your workaround?

My python script works partially, I can download the images and make the post request to resend the processed information.
However my problem is in the text recognition, with Imagemagick I have been trying to correct the images, but I get only between 8 and 14% accuracy and I can’t increase it.
I have tried quite a few image corrections with imagemagick (Morphology of Shapes -- IM v6 Examples), but I can’t get it and do research about how to bypass captchas.


Original captcha


A resize of image

Pixel smoothing

And this is the final result


I need help with

Any idea how I can improve the image processing or if there is some other method with which I can reverse the captcha.

Thanks in advance.

I was solving the same challenge and started with the same approach, which is incorrect. I found what the true path is, but it could consume too much time so I jumped to another challenge. The correct approach doesn’t use modern image processing techniques.

Hint: Visit every link in the page provided by the challenge

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