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inefficient and computationally expensive, therefore we<br />

use the following method to calculate the critical region in<br />

section B.<br />

III. FEATURES EXTRACTION<br />

In the basketball video, the basic feature consists of<br />

the color feature and histogram, which is sufficient for<br />

cluster the frame into different classes. In this section the<br />

color feature and histogram will be extracted as the input<br />

of the classifier.<br />

A. The court color detection<br />

Based on the partition of the frames we propose the<br />

implementation to detect the main color of the court. We<br />

convert the RGB to HSL in region 2 defined in section 2<br />

and calculate the main color as the frame’s color feature.<br />

Due to the sensitivity of the human eye than the right<br />

of the Hue and Saturation, we chose the Hue value of the<br />

basketball court as the feature and calculate the proportion<br />

of the court color.<br />

B. The histogram of the R2 region<br />

This section explains the histogram of the middlemost<br />

region. Due to its usage of the statistic of the pixel’s light<br />

and color without regard to the location of the pixel,<br />

histogram is one of the most used methods to calculate the<br />

inter-frame difference. Suppose D is the difference of two<br />

frames, and D is defined as:<br />

k<br />

∑ − 1<br />

k = 0<br />

D = | H[<br />

f ( x,<br />

y,<br />

t),<br />

k]<br />

− H[<br />

f ( x,<br />

y,<br />

t + 1), k] | (1)<br />

If the difference D is bigger than a threshold, the<br />

conversion occurred in the lens.<br />

B. The histogram of the key area<br />

We propose a compute-easy, yet very efficient,<br />

cinematographic algorithm for the frames with a high<br />

value. We define regions by using Golden Section spatial<br />

composition rule [8,9] , which suggests dividing up the<br />

screen in 3 : 5 : 3 proportion in both directions, and<br />

positioning the main subjects on the intersection points of<br />

these lines. We have revised this rule for basketball video,<br />

and divide the whole frame. In Figure 2, the examples of<br />

the regions obtained by Golden Section rule is displayed<br />

on several close up and in play shot.<br />

IV. CLUSTERING BY C-MEANS<br />

Clustering is a mathematical tool that attempts to<br />

discover structures or certain patterns in a data set, where<br />

the objects inside each cluster show a certain degree of<br />

similarity. In the framework of fuzzy clustering, it allows<br />

each feature vector to belong to more than one cluster with<br />

different membership degrees (between 0 and 1) and<br />

vague or fuzzy boundaries between clusters [10] . And also<br />

an alternative way of NERF C-means is proposed recently<br />

for any relational data clustering [11] .<br />

Automatic recognition of frames is a challenging<br />

problem and is highly demanded in an intelligent video<br />

surveillance system. A video can be characterized by a<br />

sequence of shots, each shot contains a frame sequence<br />

which is difference from the others.<br />

Our observation on Fig.2 has shown that similar<br />

frames share a set of similar histogram. The process<br />

involves feature extraction at the histogram to form a<br />

descriptor for each frame and clustering of the frames into<br />

a set.<br />

A. Pros and cons of FCM<br />

The popularity and usefulness of fuzzy C-means result<br />

from three facts. The algorithms are simple; they are very<br />

effective at finding minimizes of objective function J m<br />

:<br />

give data set<br />

{ }<br />

X = x1, x2, L xn<br />

(2)<br />

154

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