Fig. 1. Flow chart of robust principal component analysis algorithm based on orthogonal inexact Lagrange multiplier method

Fig. 2. CFRP test blocks with flat bottom hole defects

Fig. 3. Infrared thermal wave non-destructive synchronous testing system

Fig. 4. Infrared sequence image representation frame diagrams

Fig. 5. Temperature sampling of defect areas and non-defect areas

Fig. 6. Temperature-time variation curves between defect areas and non-defect areas

Fig. 7. Polynomial processing results of sequence images

Fig. 8. Principal component analysis processing results of sequence images

Fig. 9. Independent component image

Fig. 10. Pulse phase method results

Fig. 11. OIALM RPCA processing results