Using pairwise comparisons for estimations increases accuracy. At present,
scholars use the pairwise comparisons method to make subjective comparison between one-dimensional image and two-dimensional images. This
research is about the subjective comparison of three-dimensional images.
We rst sets a xed object volume and then uses the random method to
generate multiple three-dimensional objects with di erent shapes and then
scale them to our designed volume values. This study also virtualizes and
binarizes the image and prints the actual object in the way of 3D printing
for respondents to observe. Thirty-two respondents used the direct and
pairwise comparisons methods to rate the volume of ve randomly generated 3D shapes. It is found that using the direct method, the observer's
estimation errors is higher (in average) than when the paired comparisons
method is used. The pairwise comparisons method can improve the accuracy of estimating the volume of random objects.
