Invalid points, such as shadow and background, in the captured fringe patterns of fringe projection profilometry (FPP) are often inevitable due to the limited field of view measurements of three-dimensional (3D) imaging equipment. To ensure the quality of 3D reconstruction data, these invalid points must be identified and removed. FPP captures co-frequency-based fringe pattern sequences and approximately distributes this data along an ideal cosine curve. We propose an invalid points removal method based on an error energy function. By analyzing the relationship between the pixel values of a series of captured co-frequency patterns and an ideal cosine curve, we quantize the error energy by using a Gaussian weighted Euclidean distance. An improved Gaussian filtering method based on modulation intensity is used to significantly increase the error energy difference between the valid points of the target and the invalid points of the shadow/background area. Finally, the points whose error energy is greater than a certain error threshold are removed as invalid points. Experimental results indicate that this method can efficiently remove invalid points in fringe patterns and performs better than existing traditional methods.
The distribution of 17 Y-chromosome short tandem repeat (STR) loci, included in the AmpFlSTR®Yfiler™ amplification kit, were analyzed in six different samplings (N=878) from Sichuan, China. Haplotype diversity and discrimination capacity (DC) values were calculated. Pairwise Rst values were evaluated in AMOVA analysis and visualized through multidimensional scaling (MDS). A total of 547 unique haplotypes were detected. The observed haplotype diversity and discrimination capacity were 0.9995 and 0.7745, respectively. The homogeneity of Sichuan Han population was detected when microareas were analyzed. This population exhibited no significant genetic difference to both of the minorities in reference databases, Mongolian and Manchu, which had been through mass ethnic amalgamation with Sichuan Han population in history.