Bash: space in variable value later used as parameter

Question

While writing a bash script to help creating polaroid thumbnail using Imagick\'s convert commmand. I encounter a problem. Although, I manage to work around with

Answer 1

Putting backticks around $COMMAND on the last line causes the script to try to execute the output of the command rather than the command itself.

$ c='echo hi'
$ `$c`
hi: command not found

This will work:

if [[ "$CAPTION" != "" ]]
then
    convert -caption "$CAPTION" "$IN_FILE" "$OUTFILE"
else
    convert "$IN_FILE" "$OUTFILE"
fi