var
mybmp:timage;
TmpName: string;
begin
mybmp:=timage.create(application);
TmpName := 'C:\tempbmp.bmp';
......//转换
mybmp.picture.savetofile(TmpName);
mybmp.picture.savetofile(savepicturedialog1.filename);
你把savepicturedialog1.filename直接写成个路径不就行了