How to display an image in module's front office

[mechworm]

I have created a module that is hooked to DisplayProductExtraContent. I want to show some text and an image in the product page tabs with this module. I am able to show the text stored in mymodule.tpl file which is located in \views\templates\hook. However, I can't display the image. I tried  {html_image file='myimage.jpg'} in the tpl file but it didn't work. I copied the myimage.jpg to every sub folder of the module  and it didn't work neither. How can I display an image in module front office? 

Thanks for your help!