boofcv.examples.recognition

Class ExampleColorHistogramLookup

java.lang.Object

boofcv.examples.recognition.ExampleColorHistogramLookup

public class ExampleColorHistogramLookup
extends java.lang.Object

Demonstration of how to find similar images using color histograms. Image color histograms here are treated as features and extracted using a more flexible algorithm than when they are used for image processing. It's more flexible in that the bin size can be varied and n-dimensions are supported. In this example, histograms for about 150 images are generated. A target image is selected and the 10 most similar images, according to Euclidean distance of the histograms, are found. This illustrates several concepts; 1) How to construct a histogram in 1D, 2D, 3D, ..etc, 2) Histograms are just feature descriptors. 3) Advantages of different color spaces. Euclidean distance is used here since that's what the nearest-neighbor search uses. It's possible to compare two histograms using any of the distance metrics in DescriptorDistance too.

Constructor Summary

Constructors

Constructor and Description
ExampleColorHistogramLookup()

Method Summary

Modifier and Type	Method and Description
static java.util.List<double[]>	coupledHueSat(java.util.List<java.io.File> images) HSV stores color information in Hue and Saturation while intensity is in Value.
static java.util.List<double[]>	coupledRGB(java.util.List<java.io.File> images) Constructs a 3D histogram using RGB.
static java.util.List<double[]>	histogramGray(java.util.List<java.io.File> images) Computes a histogram from the gray scale intensity image alone.
static java.util.List<double[]>	independentHueSat(java.util.List<java.io.File> images) Computes two independent 1D histograms from hue and saturation.
static void	main(java.lang.String[] args)

Methods inherited from class java.lang.Object

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

Constructor Detail

ExampleColorHistogramLookup

public ExampleColorHistogramLookup()

Method Detail

coupledHueSat

public static java.util.List<double[]> coupledHueSat(java.util.List<java.io.File> images)

HSV stores color information in Hue and Saturation while intensity is in Value. This computes a 2D histogram from hue and saturation only, which makes it lighting independent.

independentHueSat

public static java.util.List<double[]> independentHueSat(java.util.List<java.io.File> images)

Computes two independent 1D histograms from hue and saturation. Less affects by sparsity, but can produce worse results since the basic assumption that hue and saturation are decoupled is most of the time false.

coupledRGB

public static java.util.List<double[]> coupledRGB(java.util.List<java.io.File> images)

Constructs a 3D histogram using RGB. RGB is a popular color space, but the resulting histogram will depend on lighting conditions and might not produce the accurate results.

histogramGray

public static java.util.List<double[]> histogramGray(java.util.List<java.io.File> images)

Computes a histogram from the gray scale intensity image alone. Probably the least effective at looking up similar images.

main

public static void main(java.lang.String[] args)