[ASK] How to Clean Up Black Pixel

[clouwdy]

Hello, I need help how to clean a black pixel (noise) surrounding the numbers on a image.

First, I have this Image :


I want to make the numbers is readable by Tesseract Open Source OCR Engine v3.03 with Leptonica
So I try this command line :

Code: Select all

convert img1.png -threshold 10% -morphology open "1x4: 0,1,1,0" -normalize -write MPR:source -morphology open rectangle:4x1 -negate img3.png

and the result is :


The Question is how to remove the black pixel on the second image without touching the pixels of the numbers?
Thank You

[snibgo]

This seems to be for robots to defeat captcha.

As a person who suffers from robots defeating captcha, and who also suffers from trying to login to sites that have increasingly difficult captcha, I won't help.