Does sending pictures with iMessage cost money?

I recently got my phone bill, and there's a extra costs for "picture/video message" apparently it is 50 cents for each picture sent. I have an iPhone and i use iMessage a lot more then texting. Does this cost with iMessage? Or is it just for texting?

Imessage doesn't cost, thats' the whole point of it

IMessage is free to all iDevices that have the iMessage compatibility. Does not matter what plan you are on, or who you are with, iMessage is free. I know this because it said it was before i even set up my iPhone 5. The reason why it costs money to send a picture is because you are using regular SMS. Or just a regular text message. That, does matter who you send it to.
Verizon to Verizon = Free

I'm on Verizon so i have no idea what the packages include with any other, but i know Verizon to verizon is free. Period.