The segment maxima gamut boundary descriptor is applied prevalently in cross-media color reproduction. But irregular color distribution may generate many vacant segments, especially when calculating the gamut boundary. It will reduce the accuracy of gamut boundary description seriously. This article proposes an interpolation algorithm for vacant segments based on neighboring weighted average. To address the problems caused by the coincidence between the line connecting two adjacent gamut boundary descriptor points and the constant hue plane, the reasonable solutions are given for calculating line gamut boundaries. Based on segment maxima gamut boundary descriptor, the article designs a typical gamut-clipping operator Hue-preservation Minimum E (HpMinDE) and a gamut-compressing operator. The calculation of intersections between line gamut boundaries and gamut mapping lines is also analyzed. It can help to determine quickly to which segment a gamut mapping line belongs, thus improving the gamut mapping efficiency. In the assessment, the accuracy of HpMinDE operator is evaluated by means of the color difference calculation. Then, the psychophysical experiments are employed to evaluate the preference and accuracy of the gamut-compressing operator. Finally, the computational efficiency of gamut boundary descriptor and gamut mapping operators are tested and verified.