ExpressionEngine provides the feature to add new emoticon images. I looked at ExpressionEngine user guide for Emoticon Development which doesn’t seem working for me while adding new set of emoticons.
I found the following steps, using which new emoticons can be added easily.
1) By default, emoticon images are put within the “/images/smileys/” directory. Although this directory can be updated from the Control Panel -> Admin -> System Administration -> Emoticon Preferences -> URL to the directory containing your smileys.
You can put all the new emoticon images within this directory which will be added with the existing.
2) Open the file “/expressionengine/config/smileys.php”. In this file you can see an array $smileys. Which is having all the existing emoticon images details as array elements. Same way, add more elements within this array to add new emoticon images.
Now you can see newly added emoticon images at entry’s publish/edit page for a custom field having option of “Show Smileys” as “Yes”.