You don't have to use a third party for changing the image size.
You can simply use the
width and
height in the bbcode to change the image size.
[img height=X]ImageURL[/img]
[img width=X]ImageURL[/img]
Repalce the X with the your desired width or height.
With using the above bbcode, the aspect ratio would be mainted.
You can also use the following bbcode to spesify both width and height.
[img width=X height=Y]ImageURL[/img]
Edit:
I just noticed you have used the same bbcodes. So, you know how it works.
I don't understand why you should use a thrid party as you can change the image size in the forum and with a simple bbcode. Am I missing something here?