how to detect defect for ampoule product?

[citrusgal]

Hi,

I am out of idea..anybody can give idea how to differentiate which one is the shadow and defect for image attached in this problem? One image is the perfect..one image caused of excess plastic defect as painted...and the other one is water spot occured at the surface of the ampoules...and particle defect and scracth at the surface..I already try sobel, threshold and filter...but cannot get result...and also using edge still failed due to it also detect the shadow...intensity also i have done but same issue due to of the shadow...

[muks]

Lots of clarrification needed. The perfect one also have some water defects and a hole/crack. Why is the illumination not constant? Can you try increasing the posistional accuracy. This though not highlighted enough will help you a lot is attaining repeatablity.