convert:not authorized `aaaa` @ error/constitute.c/ReadImage/453

Question

I want to create a captcha pic by use convert from ImageMagick.

And I follow this, but there are some problem .

Input In my linux shell:

Answer 1

After reading several suggestions here and combining the ideas, for me following changes in /etc/ImageMagick-6/policy.xml were necessary:

... rights="none" did not help. ...pattern="LABEL" was not neccessary. Although I do not work with big png files (only ~1 Mb) some changes in memory limits were also necessary:

(instead of 256Mib), and

(instead of 128 MB)