hi
I have not been able to find his name in any of three or four artist identification databases. Leads to the thought that he is not a listed artist. I did find a website offering a painting(s) similar to yours. It does not say Rosini painted it, but does say it was hand signed by Rosini. This distinction is important in art circles. Who painted the picture? The website offers a clue...
Pristine Fruit
If you go to the next site you will find a flower painting similar to yours signed by Rosini that apparently sold for 70 USD... (scroll up from the bottom... it's faster)
www.proxibid.com/asp/CatalogPrint.asp?aid=18535
The paintings will likely never sell for more than their original sale price and should be enjoyed for aesthetic and not commercial value. A decorative versus fine art distinction.