A Re‐Examination of Piper's Shape Analysis Technique
James Pickett, Nigel Clark, S. Shuker · Particle & Particle Systems Characterization · 1991
Abstract An image shape analysis technique which measured the angles between adjacent vectors on the image edge was previously proposed by Piper, but the accompanying data was scant. This method is shown to have great promise when applied to several images obtained using a video camera with a computer. Better data representation is obtained using a single plot of the average measured angle at each step length versus the step length. Both scale and degree of maximum roughness are immediately evident on this plot. The measured angles may be corrected to remove image circularity effects from the angles, in which case some macroscopic shape effect is also described by the plot. Similarity with the Richardson (fractal dimension) plot is discussed.