Cannot recognize STOP signboard text

Dear all experts in text recognition,

I need a favor from you guys to help me recognize the text in the STOP signboard.

I try using the code in the MATLAB documentation (https://ch.mathworks.com/help/vision/ug/automatically-detect-and-recognize-text-in-natural-images.html).

The code is successful using the given image in the example. So I try with another image, until it stop me at the STOP signboard image.

Hope you guys can help me to undertsand this problem.

Here I attach the code and the test image with the results.