Superpixels

Classes
class	cv::ximgproc::SuperpixelSEEDS
	Class implementing the SEEDS (Superpixels Extracted via Energy-Driven Sampling) superpixels algorithm described in [125] . More...

Functions
Ptr< SuperpixelSEEDS >	cv::ximgproc::createSuperpixelSEEDS (int image_width, int image_height, int image_channels, int num_superpixels, int num_levels, int prior=2, int histogram_bins=5, bool double_step=false)
	Initializes a SuperpixelSEEDS object. More...

Detailed Description

Function Documentation

Ptr<SuperpixelSEEDS> cv::ximgproc::createSuperpixelSEEDS	(	int	image_width,
		int	image_height,
		int	image_channels,
		int	num_superpixels,
		int	num_levels,
		int	prior = 2,
		int	histogram_bins = 5,
		bool	double_step = false
	)

Initializes a SuperpixelSEEDS object.

Parameters

image_width	Image width.
image_height	Image height.
image_channels	Number of channels of the image.
num_superpixels	Desired number of superpixels. Note that the actual number may be smaller due to restrictions (depending on the image size and num_levels). Use getNumberOfSuperpixels() to get the actual number.
num_levels	Number of block levels. The more levels, the more accurate is the segmentation, but needs more memory and CPU time.
prior	enable 3x3 shape smoothing term if >0. A larger value leads to smoother shapes. prior must be in the range [0, 5].
histogram_bins	Number of histogram bins.
double_step	If true, iterate each block level twice for higher accuracy.

The function initializes a SuperpixelSEEDS object for the input image. It stores the parameters of the image: image_width, image_height and image_channels. It also sets the parameters of the SEEDS superpixel algorithm, which are: num_superpixels, num_levels, use_prior, histogram_bins and double_step.

The number of levels in num_levels defines the amount of block levels that the algorithm use in the optimization. The initialization is a grid, in which the superpixels are equally distributed through the width and the height of the image. The larger blocks correspond to the superpixel size, and the levels with smaller blocks are formed by dividing the larger blocks into 2 x 2 blocks of pixels, recursively until the smaller block level. An example of initialization of 4 block levels is illustrated in the following figure.

image