Does iTunes automatically compress pictures?

[iqwertyi]

do I need to adjust the image size of my pics or does iTunes automatically compress them for me? I just don't want to take that much space just for pictures ony phone. Thanks

 

[andreas4]

In my case, it has compressed 5GB of photos into less than 800MB. Automatically.

 

[iqwertyi]

Thanks for the quick response.
Much appreciated