Stitching path optimization for a rough surface interference test.

Area of Science:

• Optical Metrology
• Interferometry
• Image Processing

Background:

• Phase unwrapping is essential in phase-shifting interferometry, directly affecting measurement precision.
• The discrete cosine transform-based least-squares (DCT-LS) method is used for unwrapping rough surface interference data.
• DCT-LS can introduce global phase errors despite providing smooth results.

Purpose of the Study:

• To suppress error propagation in least-squares phase unwrapping.
• To improve the unwrapping results for rough surfaces using a novel stitching approach.
• To optimize the stitching path for enhanced accuracy.

Main Methods:

• Implemented a block phase unwrapping and stitching scheme.
• Developed an optimized stitching path planning method.
• Validated through simulations and experimental optical processing.

Main Results:

• The block phase unwrapping and stitching method significantly reduces global phase errors.
• Optimized stitching path planning yields superior unwrapping results compared to serpentine paths.
• The proposed method enhances the precision of phase measurement for rough surfaces.

Conclusions:

• Block phase unwrapping with optimized stitching effectively mitigates errors in DCT-LS.
• The optimized path planning is crucial for achieving accurate phase unwrapping of rough surfaces.
• This approach offers a more reliable solution for optical processing applications requiring precise phase measurements.