调用时Akima(Omg, 5, flag) //Omg表示为图像中每行中5个相邻点的灰度值（是一个数组），5代表选择5点进行插值，flag为插值精度，整个函数返回插值后的灰度值（亚像素精度的）-When calling Akima (Omg, 5, flag)// Omg represented in each row in the image gray value of 5 adjacent points (an array), select 5:00 5 represents an int