QI Zi-cheng,NI Pei-jun,JIANG Wei,et al.Spatial resolution measurement of industrial CT system based on equal diameter circumscribed circle phantom[J].Optics and Precision Engineering,2021,29(01):61-71.
QI Zi-cheng,NI Pei-jun,JIANG Wei,et al.Spatial resolution measurement of industrial CT system based on equal diameter circumscribed circle phantom[J].Optics and Precision Engineering,2021,29(01):61-71. DOI: 10.37188/OPE.20212901.0061.
Spatial resolution measurement of industrial CT system based on equal diameter circumscribed circle phantom
Spatial resolution measurement of industrial CT based on a periodic structure phantom has strict requirements on the machining accuracy of the phantom, which affects the practicability and accuracy of the method. To address this issue, a spatial resolution measurement technique of industrial CT based on an equal-diameter circumscribed circle is proposed. First, the measurement mechanism of the line-pair-card is analyzed. The equal-diameter circumscribed circle phantom was designed to form a continuous variable-spacing structure. The equivalence relation between the variable spacing structure and strip structure (line-pair-card) is derived. A spatial resolution measurement technique of industrial CT is established based on an equal-diameter circumscribed circle. Then, an automatic measurement method of spatial resolution is realized using an image processing algorithm. The results of this method are similar to those of the line-pair-card measurement, and the relative error is within 10%. This method has fewer requirements for the machining accuracy of phantoms. The measurement process is simple and practical.
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