Real-time feature extraction from video stream data for stream ...

ai.cs.uni.dortmund.de

Real-time feature extraction from video stream data for stream ...

6. Feature Extraction

Mean

Median

Standard Deviation

Skewness

Kurtosis

Peak

Min Gray Value

Max Gray Value

Center of Mass

Normalized Center of Mass

Area Fraction

Edginess

The average gray value of the input image.

The median gray value of the input image.

The standard deviation of the gray values.

The skewness of the gray values.

The kurtosis of the gray values.

Include peak color from histogram and its relative

value.

Include Minimum Gray value in the image.

Include Maximum Gray value in the image.

Delivers two features X and Y, denoting the X- and

Y-coordinate of the brightness-weighted average of the

X and Y coordinates of all pixels in the image.

Delivers two features X and Y. Same as Center of

Mass, but normalized, so that the size of the image

doesn’t matter.

The percentage of non-zero pixels.

Relative count of white (255) pixels after applying

”Find edges” operator.

Table 6.1.: Overview of image features that can be extracted using the Global Statistics-

Operator of the IMMI Extension

(a) Original image

(b) Color histogram

Figure 6.7.: Example of a color histogram for a ”Tagesschau” frame.

6.2.2. The overall feature extraction process in RapidMiner

Using the above described operators, I designed a RapidMiner experiment to extract

video features from a set of images, extracted from a video file by using xuggler. A

screenshot of the main part of the experiment is shown in figure 6.9.

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