Optical inspection system of eliminating image noise

An optical inspection system of removing a pattern relevant to surface metallic texture on a circuit from an image to be inspected, the optical inspection system comprising:

• a first polarizer disposed on a position facing the circuit, and having a first polarization axis;
• a linear light source configured to emit a linear light beam passing through the first polarizer to project polarization beam onto the circuit;
• a second polarizer disposed on another position facing the circuit and different from the first polarizer, a second polarization axis of the second polarizer being intersected by the first polarization axis;
• an optical detector adapted to receive a reflection beam generated by the linear polarization beam reflected from the circuit and passing through the second polarizer;
• and
• an operation processor electrically connected to the optical detector, and adapted to receive the image to be inspected generated by the reflection beam, and further to analyze the image to be inspected for determining whether the circuit has any defect except the surface metallic texture;
• wherein the operation processor decides a position of at least one pixel within the image to be inspected has the defect when a difference between a grey level of the at least one pixel within the image to be inspected and a grey level computation value of pixels within the image to be inspected is greater than a preset threshold.