boofcv.struct.pyramid

Interface ImagePyramid<T extends ImageBase>

All Known Implementing Classes:

ImagePyramidBase, PyramidDiscrete, PyramidDiscreteAverage, PyramidDiscreteSampleBlur, PyramidFloat, PyramidFloatGaussianScale, PyramidFloatScale

public interface ImagePyramid<T extends ImageBase>

Image pyramids represent an image at different resolution in a fine to coarse fashion. Lower layers in the pyramid are at a higher resolution than the upper layers. The resolution of a layer is specified by its scale. The scale number indicates how many pixels in the original input image correspond to a single pixel at the current layer. So a layer with a scale of 5 is 5 times lower resolution than the input layer.

The transform from a pixel coordinate in layer 'i' to the original image will vary depending on the pyramid is constructed. In general it, can be described by the following equation: (x,y) = (offX_i,offY_i) + scale_i*(x_i,y_i), where (x_i,y_i) is the pixel coordinate in layer 'i'. The offsets (offX_i,offY_i) vary depending on how each layer in the pyramid samples the previous layers. This offset can be found by calling getSampleOffset(int).

Author:

Peter Abeles

Method Summary

Methods

Modifier and Type	Method and Description
int	getHeight(int layer) Returns the height of an image at ths specified layer.
Class<T>	getImageType() The type of image.
int	getInputHeight() Height of input image.
int	getInputWidth() Width of input image.
T	getLayer(int layerNum) Returns a layer in the pyramid.
int	getNumLayers() Returns the number of layers in the pyramid.
double	getSampleOffset(int layer) Returns the sampling offset.
double	getScale(int layer) Returns the scale of the specified layer in the pyramid.
double	getSigma(int layer) Returns the scale-space scale for the specified layer.
int	getWidth(int layer) Returns the width of an image at ths specified layer.
void	initialize(int width, int height) Declares internal data structures for an image with the specified dimensions
void	process(T input) Constructs the image pyramid given the input image.
void	setTo(ImagePyramid<T> input) Set's this pyramid to be the same as input.

Method Detail

process

void process(T input)

Constructs the image pyramid given the input image.

initialize

void initialize(int width,
              int height)

Declares internal data structures for an image with the specified dimensions

Parameters:

width - image width

height - image height

getScale

double getScale(int layer)

Returns the scale of the specified layer in the pyramid. Larger the scale smaller the image is relative to the input image.

Parameters:

layer - Which layer is being inspected.

Returns:

The layer's scale.

getLayer

T getLayer(int layerNum)

Returns a layer in the pyramid.

Parameters:

layerNum - which image is to be returned.

Returns:

The image in the pyramid.

getNumLayers

int getNumLayers()

Returns the number of layers in the pyramid.

getWidth

int getWidth(int layer)

Returns the width of an image at ths specified layer.

Parameters:

layer - The layer being requested.

Returns:

The layer's width.

getHeight

int getHeight(int layer)

Returns the height of an image at ths specified layer.

Parameters:

layer - The layer being requested.

Returns:

The layer's height.

getInputWidth

int getInputWidth()

Width of input image.

getInputHeight

int getInputHeight()

Height of input image.

getImageType

Class<T> getImageType()

The type of image.

Returns:

Image type.

setTo

void setTo(ImagePyramid<T> input)

Set's this pyramid to be the same as input. The two pyramids must have the same structure or else an exception will be thrown.

Parameters:

input - Input pyramid. Not modified.

getSampleOffset

double getSampleOffset(int layer)

Returns the sampling offset. Both x and y axises are assumed to have the same offset. See comment in constructor above.

Parameters:

layer - Layer in the pyramid

Returns:

Sampling offset in pixels.

getSigma

double getSigma(int layer)

Returns the scale-space scale for the specified layer. This scale is equivalent amount of Gaussian blur applied to the input image. If Gaussian blur is not applied to each layer then an approximation should be returned.

Parameters:

layer - Layer in the pyramid

Returns:

Equivalent sigma for Gaussian blur.