Both Terms of Imari and Famille rose are used very Broadly today. But to be more specfic Imari is from the Imari Area, Though they have a style it should be used for Porcelain from that area. Famille Rose is a term used by the french, basically for Family, Which is used for the Chinese style with Rose for the most part, your plate would be more Famille Rose then Imari, but like I said earlier these terms are used so broadly today, that I usually don't use them unless they are solid in these parameters. I would have to look closer at the marks, but keep in mind most Asian style marks can easy fool us Westerners, in many cases they will use the mark of old masters and Dynasties. Of course they will tell you that it is to honor the original artist, my Asian Friend Laughs every time he heard that.