How to merge images at the command line with ImageMagick

This is a quick article on how to merge a set of images, under Linux, at the command line using the convert command of ImageMagick.

To merge a set of images into a horizontal line, use the -append flag with convert. Here is an example:

convert a*.png -append arow.png

To merge a set of images into a vertical line, use the +append flag with convert. Here is an example:

convert b*.png +append bcolumn.png

Source: https://stackoverflow.com/a/21325493/11034541