（转载）lire使用，创建索引

LIRE（Lucene Image REtrieval）提供一种的简单方式来创建基于图像特性的Lucene索引。利用该索引就能够构建一个基于内容的图像检索(content- based image retrieval，CBIR)系统，来搜索相似的图像。LIRE使用的特性都取自MPEG-7标准： ScalableColor、ColorLayout、EdgeHistogram。

使用DocumentBuilderFactory 创建 DocumentBuilder，例如DocumentBuilderFactory.getCEDDDocumentBuilder(). 

将图片加入索引index 需要以下2步：

• 使用 DocumentBuilder 创建Document：builder.createDocument(FileInputStream, String).（第一个参数是图片文件）
• 将document 加入 index.

 LIRE支持很多种的特征值。具体可以看 DocumentBuilderFactory 类的源代码。也可以使用 ChainedDocumentBuilder 同时使用多种特征值。

创建索引的方法如下代码所示

 

package liretest;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import javax.imageio.ImageIO;
import org.apache.lucene.analysis.core.WhitespaceAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.store.FSDirectory;
import net.semanticmetadata.lire.DocumentBuilder;
import net.semanticmetadata.lire.DocumentBuilderFactory;
import net.semanticmetadata.lire.utils.FileUtils;
import net.semanticmetadata.lire.utils.LuceneUtils;

public class Indexer {
public static void main(String[] args) throws IOException {

// Checking if arg[0] is there and if it is a directory.

boolean passed = false;
if (args.length > 0) {
File f = new File(args[0]);
System.out.println("Indexing images in " + args[0]);
if (f.exists() && f.isDirectory())
passed = true;
}
if (!passed) {
System.out.println("No directory given as first argument.");
System.out
.println("Run \"Indexer <directory>\" to index files of a directory.");
System.exit(1);
}

// Getting all images from a directory and its sub directories.
ArrayList<String> images = FileUtils.getAllImages(new File(args[0]),
true);
// Creating a CEDD document builder and indexing al files.
DocumentBuilder builder = DocumentBuilderFactory
.getCEDDDocumentBuilder();
// Creating an Lucene IndexWriter
IndexWriterConfig conf = new IndexWriterConfig(
LuceneUtils.LUCENE_VERSION, new WhitespaceAnalyzer(
LuceneUtils.LUCENE_VERSION));
IndexWriter iw = new IndexWriter(FSDirectory.open(new File("d:\\index")),
conf);
// Iterating through images building the low level features
for (Iterator<String> it = images.iterator(); it.hasNext();) {
String imageFilePath = it.next();
System.out.println("Indexing " + imageFilePath);
try {
BufferedImage img = ImageIO.read(new FileInputStream(
imageFilePath));
Document document = builder.createDocument(img, imageFilePath);
iw.addDocument(document);
} catch (Exception e) {
System.err.println("Error reading image or indexing it.");
e.printStackTrace();
}
}

// closing the IndexWriter
iw.close();
System.out.println("Finished indexing.");

}
}