A measure of golf logo contour quality by piecewise interpolation of the accumulation of turn angle

There is a demanding need for manufacturers to reduce the escape rate of inspection of golf logos. The quality of the logo is primarily depending on the small and local deviation of the logo contours. In this study, the concept of mathematical piecewise continuous approximation and the accumulation of turn angles (ATA) are employed to deal with the problem of different degrees of contour stretching and shrinking. Each of the test contours, as well as the sample one, is partitioned into a number of sub-contours. The ATA values for each sub-contour form an ATA sub-chain, and all the sub-chains in sequence form an ATA chain for the overall contour. The sizes of the sample and test ATA chains are to be compared and "rescaled" by interpolation. Through the study, the correspondence problem can be explored in detail. Lots of experimental and simulation examples have been conducted to support the adequacy of the proposed measure. The results of this study can be useful for fine inspection of the object quality based on detecting small and local deviation of the object image contour.