Inspection of casting castings

There is a great need for inspection of castings.

THE FACT IS, HOWEVER, THAT SUBTLE NG IS DIFFICULT TO DISCERN.

The visual inspector actually inspects the workpiece while tilting it.

This means,

1. illumination is from one direction and the workpiece is tilted for repeated inspections.

2. inspect from various directions while switching the lighting.

It is believed that only one of these can be determined.

We actually tried in case 2 and obtained the following image.

I am posting this for your information.

These images were obtained by switching the lighting from 8 directions.

THE CHALLENGE IS HOW TO SEPARATE OK/NG FROM HERE...