Multi-frequency noise for LIC
Ming-Hoe Kiu, David C. Banks · 1996
We present a way to visualize a flow field using Line Integral Convolution (LIC) with a multi--frequency noise texture. A broad range of feature sizes can enhance a user's perception of the magnitudes and direction of the flow. In addition, the multiple scales of feature size help a user clarify the motion of the flow in an animation. 1. Introduction In the field of scientific visualization, Line Integral Convolution [1] is used to create an image of streaks to show the flow--direction in a vector field. LIC convolves a white--noise image with a filter function aligned with an underlying vector field. This method avoids the problems of over--crowding that can occur when explicitly-- drawn streamlines converge in an image; LIC preserves the overall density of bright and dark streaks. This paper discribes how to adjust the spatial frequency (and hence the feature size) of the noise image so that the resulting LIC image makes long, fat streaks in areas of high velocity and short thin str...