MULTI-FEATURE-MARKS BASED INFORMATION EXTRACTION OF URBAN GREEN SPACE ALONG ROAD

Green space along road of QuickBird image was studied in this paper based on multi-feature-marks in frequency domain. The magnitude spectrum of green along road was analysed, and the recognition marks of the tonal feature, contour feature and the road were built up by the distribution of frequency channels. Gabor filters in frequency domain were used to detect the features based on the recognition marks built up. The detected features were combined as the multi-feature-marks, and watershed based image segmentation were conducted to complete the extraction of green space along roads. The segmentation results were evaluated by Fmeasure with <i>P</i>&amp;thinsp;=&amp;thinsp;0.7605，<i>R</i>&amp;thinsp;=&amp;thinsp;0.7639，<i>F</i>&amp;thinsp;=&amp;thinsp;0.7622.

On the Watercolor Illusion

The watercolor illusion is a long-range assimilative spread of color emanating from a thin colored line running contiguous to a darker chromatic contour and imparting a figure-ground effect across a large area. The watercolored figure appears evenly colored by an opaque light veil of chromatic tint (coloration effect), with a clear surface color property spreading from the lighter edges. At the same time, the watercolored figure manifests a strong figure-ground organization and a solid figural appearance comparable to a rounded surface segregated in depth which extends out from the flat surface. The complementary region appears as a hole or empty space. The phenomenal properties of coloration and figure-ground effects and their relationship are described and demonstrated. The watercolor illusion and its main effects are discussed in the light of parallel mechanisms. Boundary and surface dynamics are processed by the boundary contour system and by the feature contour system.