org.openimaj.image.analysis.algorithm.histogram.binning

Class QuadtreeStrategy

java.lang.Object

org.openimaj.image.analysis.algorithm.histogram.binning.QuadtreeStrategy

All Implemented Interfaces:

SpatialBinningStrategy

public class QuadtreeStrategy
extends Object
implements SpatialBinningStrategy

A SpatialBinningStrategy that extracts histograms from regions defined by a fixed depth quadtree overlayed over the sampling region and concatenates them together.

Author:

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

Constructor Summary

Constructors

Constructor and Description
QuadtreeStrategy(int nlevels) Construct with the given quadtree depth

Method Summary

Modifier and Type	Method and Description
Histogram	extract(WindowedHistogramExtractor binnedData, Rectangle region, Histogram output) Extract a histogram describing image content in the given region using the given WindowedHistogramExtractor to extract (sub) histograms from which to build the output.

Methods inherited from class java.lang.Object

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

Constructor Detail

QuadtreeStrategy

public QuadtreeStrategy(int nlevels)

Construct with the given quadtree depth

Parameters:

nlevels - quadtree depth

Method Detail

extract

public Histogram extract(WindowedHistogramExtractor binnedData,
                         Rectangle region,
                         Histogram output)

Description copied from interface: SpatialBinningStrategy

Extract a histogram describing image content in the given region using the given WindowedHistogramExtractor to extract (sub) histograms from which to build the output.

For efficiency, this method allows the output histogram to be specified as an input. This means that implementors of this interface can attempt to fill the output histogram rather than creating a new instance (although care should be taken to ensure that the porivded output histogram is the correct size and not null).

Users of SpatialBinningStrategys should use the following style for maximum efficiency:

 Histogram h = null;
 ...
 for (Rectangle region : lots_of_regions)
        h = strategy.extract(binnedData, region, h);
 

Specified by:

extract in interface SpatialBinningStrategy

Parameters:

binnedData - the WindowedHistogramExtractor to extract sub-histograms from

region - the region to extract from

output - the output histogram to fill (can be null)

Returns:

the extracted histogram (preferably output)