Effect of noise smoothing in 3-D surface display
Keh‐Shih Chuang, Bruce K. T. Ho, Christine J. Wu, Doris T. Chin · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1992
Images are subjects to various types of noises. Noise carries no useful information and deteriorates image quality. Most of the studies on noise are for projectional radiography; few are on the effect of 3-D images. In this paper we studied the effect of noise on the 3-D surface display and compared three techniques to smooth out noise. The three smoothing techniques used are averaging, median filter, and Butterworth filter. The performances of these techniques are compared. For averaging and median filter techniques, smoothing is performed on each slice of the 3-D data set. The Butterworth filter is performed on the 3-D cosine transform of the data. Then the 3-D surface is reconstructed from these smoothed data. It was found that all of the three techniques can smooth out the noise effectively. The effect of noise on the 3-D image is enhancement of the slicing artifacts. The 3-D Butterworth filter can eliminate the slicing artifacts. The blurring artifact which is prevalent in 2-D smoothing do not show up in the 3-D display.