Effects of manual threshold setting on image analysis results of a sandstone sample structural characterization by X-ray microtomography

Binarization process plays an important role in structural characterization by means of micro-CT images analysis. The choice of the correct threshold to separate porous phase from the material is the procedure for binary images creation. Slight variations of the threshold level led to substantial variations in physical parameters determination. The aim of this work is to evaluate these variations based on manual threshold settings data of five operators. Porosity and pore size distribution of a sandstone sample were determined.

► Binarization process is the most important step for structural characterization in image analysis.
► Algorithms to automatic threshold setting can be not adequate to some kind of pore structures.
► The threshold choice of five operators was compared to two threshold setting algorithms.
► Manual threshold setting maybe is the only reliable technique for reservoir rocks image analysis.
► Qualitative data shows inadequate threshold choice of an algorithm in comparison to manual setting.