Hi and Welcome to the Forum!
Yes this is certainly possible. It is done in the same was as applying a texture to a surface.
Proceed as if you wanted to change the surface texture - In the Textures list choose Pictures and instead of choosing one of the existing pictures right click on one of them and select Add Element - browse to your image and it will be added to your textures list.
To apply it to fill the surface you need to overide the default size and set it to the size of the area you want it to fill. If you use the Mapping button on the Appearance tab for your imported image, you can change the size and also use the arrow buttons to move the image across the surface so it aligns with the edge of your object.
You may also find some askpects of this post usefull:
http://forums.turbofloorplan.com/index.php/topic,1227.0.htmlI must admit I do not know what a palapa is but the principle of adding an image is the same regardless of what it is applied to.
I hope that explanation is not too brief - ask again if you do not follow it completely.
Allan