diff --git a/storage.go b/storage.go
index ca69e83..1c5f693 100644
--- a/storage.go
+++ b/storage.go
@@ -14,6 +14,9 @@ type StorageInstance interface {
 	SaveImgBytes(b []byte, imgdir string, force bool, samediff int) (string, string)
 	SaveImg(r io.Reader, imgdir string, samediff int) (string, string)
 	ScanImgs(imgdir string)
+	IsImgExsits(name string) bool
+	AddImage(name string)
+	Pick(exclude []string) string
 }
 
 type storage struct {