org.openimaj.image.feature.local.keypoints

Class KeypointVisualizer<T,Q extends Image<T,Q> & SinglebandImageProcessor.Processable<Float,FImage,Q>>

java.lang.Object

org.openimaj.image.feature.local.keypoints.KeypointVisualizer<T,Q>

Type Parameters:

T -

Q -

public class KeypointVisualizer<T,Q extends Image<T,Q> & SinglebandImageProcessor.Processable<Float,FImage,Q>>
extends Object

Helpers for visualising (SIFT) interest points.

Author:

Jonathon Hare (jsh2@ecs.soton.ac.uk)

Constructor Summary

Constructors

Constructor and Description
KeypointVisualizer(Q image, List<? extends Keypoint> keys) Construct the visualiser with the given image and keypoints.

Method Summary

Modifier and Type	Method and Description
Q	drawCenter(T col) Draw the centre point of the keypoints on an image
Q	drawPatches(T boxColour, T circleColour) Draw the sampling boxes on an image.
static <T,Q extends Image<T,Q> & SinglebandImageProcessor.Processable<Float,FImage,Q>> Q	drawPatchesInplace(Q image, List<? extends Keypoint> keypoints, T boxColour, T circleColour) Draw the SIFT features onto an image.
Map<Keypoint,Q>	getPatches(int dim) Extract the oriented sampling patches used in the construction of the keypoints.
static Polygon	getSamplingBox(Keypoint k) Get the sampling area of an single feature as a polygon.
static Polygon	getSamplingBox(Keypoint k, float scincr) Get the sampling area of an single feature as a polygon.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

KeypointVisualizer

public KeypointVisualizer(Q image,
                          List<? extends Keypoint> keys)

Construct the visualiser with the given image and keypoints.

Parameters:

image - the image

keys - the keypoints

Method Detail

getPatches

public Map<Keypoint,Q> getPatches(int dim)

Extract the oriented sampling patches used in the construction of the keypoints. The patches are normalised to the given fixed size.

Parameters:

dim - the patch size.

Returns:

images depicting the sampling patches of each feature

drawPatches

public Q drawPatches(T boxColour,
                     T circleColour)

Draw the sampling boxes on an image.

Parameters:

boxColour - the sampling box colour

circleColour - the scale-circle colour

Returns:

an image showing the features.

drawPatchesInplace

public static <T,Q extends Image<T,Q> & SinglebandImageProcessor.Processable<Float,FImage,Q>> Q drawPatchesInplace(Q image,
                                                                                                                   List<? extends Keypoint> keypoints,
                                                                                                                   T boxColour,
                                                                                                                   T circleColour)

Draw the SIFT features onto an image. The features are visualised as circles with orientation lines showing the scale and orientation, and with oriented squares showing the sampling region. The colours of the squares and circles is controlled individually. Setting the colour to null will cause the shape not to be displayed. The sizes of the drawn shapes assume the default SIFT settings described by Lowe. If the parameters used to find the keypoints have been changed, then the features might not be drawn at the correct size.

Type Parameters:

T - the pixel type

Q - the image type

Parameters:

image - the image to draw on

keypoints - the features to draw

boxColour - the colour of the sampling boxes

circleColour - the colour of the scale circle

Returns:

the input image

drawCenter

public Q drawCenter(T col)

Draw the centre point of the keypoints on an image

Parameters:

col - the colour to draw with

Returns:

the image

getSamplingBox

public static Polygon getSamplingBox(Keypoint k)

Get the sampling area of an single feature as a polygon.

Parameters:

k - the feature

Returns:

the polygon representing the sampling area.

getSamplingBox

public static Polygon getSamplingBox(Keypoint k,
                                     float scincr)

Get the sampling area of an single feature as a polygon.

Parameters:

k - the feature

scincr - the scaling factor to apply to the sampling area

Returns:

the polygon representing the sampling area.