Contours maps (such as topographic maps) compress the information of a function over a two-dimensional area into a discrete set of closed lines that connect points of equal value (isolines), striking a fine balance between expressiveness and cognitive simplicity. They allow humans to perform many common sense reasoning tasks about the underlying function (e.g. elevation). This paper analyses an...

This paper presents a technique to segment and track a region of interest in a video sequence. The presented technique starts with a spatio-temporal contour extraction. This contour extraction is performed by mixing information from a spatial gradient and a temporal di erentiator. A block segmentation is then applied on the image, and within each block the contour part is approximated by a stra...

The phase-only logarithmic radial harmonic (LRH) filter has been shown to be suitable for scale-invariant block object recognition. However, an important set of objects is the collection of contour functions that results from a digital edge extraction of the original block objects. These contour functions have a constant width that is independent of the scale of the original object. Therefore, ...

We present a lip contour tracking algorithm using attractorguided particle filtering. Usually it is difficult to robustly track the lip contour because the lip contour is highly deformable and the contrast between skin and lip colors is very low. It makes the traditional blind segmentation-based algorithms often fail to have robust and realistic results. But in fact, the lip contour is constrai...

In this system we improved the performance of an automatic system for extracting leaf contour. The proposed leaf contour extraction method consists of three major procedures: the detection of four edge points, and contour tracing. Leaf detection includes two stages: feature extraction and matching. For the leaf contour extraction part, we present a new technique for automatically identifying th...