Fig. 1. Composition of wafer motion imaging system

Fig. 2. Process of wafer motion imaging exposure control

Fig. 3. Image of typical die

Fig. 4. Image segmentation using OTSU algorithm

Fig. 5. Image segmentation using blocked OTSU algorithm

Fig. 6. Trend of classes variance with different block quantities

Fig. 7. High and low frequency components of die images under different brightness

Fig. 8. Comparison of normalized evaluation values before and after Gaussian pyramid down sampling

Fig. 9. Relationship between dynamic weight and grayscale

Fig. 10. Process of search algorithm

Fig. 11. Pseudocode for step size selection program

Fig. 12. Different evaluation curves for three types of dies

Fig. 13. Comparison of exposure effects of different methods in different regions