用于从值显示EQ图像的更高效代码

Basically what im doing is using NAudio to get peak info. I've made a set of 20 images that are going to represent the EQ. I've done some code to check the peak value and change the image in the picturebox in realtime with a timer. Though sometimes I see visual lag and I think the code is quite inefficient. Is there a more efficient code than this large chunk of ifsBasically what im doing is using NAudio to get