Table 1.

Different convolution approaches used to estimate the image derivative [17]. The use of one of them depends of scene conditions. Usually, derivative approaches used for border detection, results better descriptor of the texture of moving objects.

Approach	Derivative Approximation
Convolution Mask	Simple Derivative.
	Sobel Mask.
	Prewitt Mask.
	Laplacian Mask.
	Roberts Mask.
	Deriche Mask.
Morphological Operator	Inner Derivative.
	Outer Derivative.