Preview Default Coloured ImageMagick Speech Bubble Extraction and Background Image Overlay

RJM Programming - October, 2025

Thanks to https://github.com/ImageMagick/ImageMagick/discussions/4606 and https://stackoverflow.com/questions/71094480/how-to-execute-multi-line-command-with-shell-exec

Base image URL:  
Overlay image URL:   a Preview inspired Speech Bubble extracted image regarding could not be created via ImageMagick (convert: unrecognized option `-color-threshold' @ error/convert.c/ConvertImageCommand/1171. ) from