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LIRE Solr Integration Project

This is a Solr plugin for the LIRE content based image retrieval library, so basically it's for indexing images and then finding similar (looking) ones. The original library can be found at https://code.google.com/p/lire/

The LIRE Solr plugin includes a RequestHandler for searching, an EntityProcessor for indexing, a ValeSource Parser for content based re-ranking and a parallel indexing application.

A demo can be found at http://demo-itec.uni-klu.ac.at/liredemo/

If you need help on the plugin, please use the mailing list at http://groups.google.com/group/lire-dev to ask questions. If you need help with your project, please contact me, we also offer consulting services.

If you use LIRE Solr for scientific purposes, please cite the following paper:

Lux, Mathias, and Glenn Macstravic. "The LIRE Request Handler: A Solr Plug-In for Large Scale Content Based Image Retrieval." MultiMedia Modeling. Springer International Publishing, 2014.

The request handler supports four different types of queries

  1. Get random images ...
  2. Get images that are looking like the one with id ...
  3. Get images looking like the one found at url ...
  4. Get images with a feature vector like ...
  5. Extract histogram and hashes from an image URL ...

Preliminaries

Supported values for feature field parameters, e.g. lireq?field=cl_ha:

  • cl_ha .. ColorLayout
  • ph_ha .. PHOG
  • oh_ha .. OpponentHistogram
  • eh_ha .. EdgeHistogram
  • jc_ha .. JCD
  • ce_ha .. CEDD
  • sc_ha .. ScalableColor

The field parameter (partially) works with the LIRE request handler:

  • fl .. Fields, give them as a comma or space separated list, like "fl=title,id,score". Note that "*" is denoting all fields and score adds the distance (which already comes with the "d" fields) in an additional score field.
  • fq .. Filter query, give them as a comma separated list in the format "fq=tags:dog tags:funny". No wildcards and no spaces in terms supported for now.

Getting random images

Returns randomly chosen images from the index.

Parameters:

  • rows ... indicates how many results should be returned (optional, default=60). Example: lireq?rows=30

Search by ID

Returns images that look like the one with the given ID.

Parameters:

  • id .. the ID of the image used as a query as stored in the "id" field in the index.
  • field .. gives the feature field to search for (optional, default=cl_ha, values see above)
  • rows .. indicates how many results should be returned (optional, default=60).
  • accuracy .. double in [0.05, 1] indicates how many accurate the results should be (optional, default=0.33, less is less accurate, but faster).
  • candidates .. int in [100, 100000] indicates how many accurate the results should be (optional, default=10000, less is less accurate, but faster).

Search by URL

Returns images that look like the one found at the given URL.

Parameters:

  • url .. the URL of the image used as a query. Note that the image has to be accessible by the web server Java has to be able to read it.
  • field .. gives the feature field to search for (optional, default=cl_ha, values see above)
  • rows .. indicates how many results should be returned (optional, default=60).
  • accuracy .. double in [0.05, 1] indicates how many accurate the results should be (optional, default=0.33, less is less accurate, but faster).
  • candidates .. int in [100, 100000] indicates how many accurate the results should be (optional, default=10000, less is less accurate, but faster).

Search by feature vector

Returns an image that looks like the one the given features were extracted. This method is used if the client extracts the features from the image, which makes sense if the image should not be submitted.

Parameters:

  • hashes .. Hashes of the image feature as returned by BitSampling#generateHashes(double[]) as a String of white space separated numbers.
  • feature .. Base64 encoded feature histogram from LireFeature#getByteArrayRepresentation().
  • field .. gives the feature field to search for (optional, default=cl_ha, values see above)
  • rows .. indicates how many results should be returned (optional, default=60).
  • accuracy .. double in [0.05, 1] indicates how many accurate the results should be (optional, default=0.33, less is less accurate, but faster).
  • candidates .. int in [100, 100000] indicates how many accurate the results should be (optional, default=10000, less is less accurate, but faster).

Extracting histograms

Extracts the histogram and the hashes of an image for use with the lire sorting function.

Parameters:

  • extract .. the URL of the image. Note that the image has to be accessible by the web server Java has to be able to read it.
  • field .. gives the feature field to search for (optional, default=cl_ha, values see above)

Installation

First run the dist task (ant task, in build.xml, check Apache Ant if you have not used it before, or try it in Intellij IDEA) to create a single jar. This should be integrated in the Solr class-path. Then add the new request handler has to be registered in the solrconfig.xml file:

 <requestHandler name="/lireq" class="net.semanticmetadata.lire.solr.LireRequestHandler">
    <lst name="defaults">
      <str name="echoParams">explicit</str>
      <str name="wt">json</str>
      <str name="indent">true</str>
    </lst>
 </requestHandler>

Use of the request handler is detailed above.

You'll also need the respective fields in the schema.xml file:

<fields>
   <!-- file path for ID -->
   <field name="id" type="string" indexed="true" stored="true" required="true" multiValued="false" />
   <!-- the sole file name -->
   <field name="title" type="text_general" indexed="true" stored="true" multiValued="true"/>
   <!-- Edge Histogram -->
   <field name="eh_ha" type="text_ws" indexed="true" stored="false" required="false"/>
   <field name="eh_hi" type="binaryDV"  indexed="false" stored="true" required="false"/>
   <!-- ColorLayout -->
   <field name="cl_ha" type="text_ws" indexed="true" stored="false" required="false"/>
   <field name="cl_hi" type="binaryDV"  indexed="false" stored="true" required="false"/>
   <!-- PHOG -->
   <field name="ph_ha" type="text_ws" indexed="true" stored="false" required="false"/>
   <field name="ph_hi" type="binaryDV"  indexed="false" stored="true" required="false"/>
   <!-- JCD -->
   <field name="jc_ha" type="text_ws" indexed="true" stored="false" required="false"/>
   <field name="jc_hi" type="binaryDV"  indexed="false" stored="true" required="false"/>
   <!-- OpponentHistogram -->
   <!--field name="oh_ha" type="text_ws" indexed="true" stored="false" required="false"/-->
   <!--field name="oh_hi" type="binaryDV"  indexed="false" stored="true" required="false"/-->
   <!-- Needed for SOLR -->
   <field name="_version_" type="long" indexed="true" stored="true"/>
</fields>

Do not forget to add the custom field at the very same file:

<fieldtype name="binaryDV" class="net.semanticmetadata.lire.solr.BinaryDocValuesField"/>

There is also a sort function based on LIRE. The function parser needs to be added to the solarconfig.xml file like this:

  <valueSourceParser name="lirefunc"
    class="net.semanticmetadata.lire.solr.LireValueSourceParser" />

Then the function lirefunc(arg1,arg2) is available for function queries. Two arguments are necessary and are defined as:

  • Feature to be used for computing the distance between result and reference image. Possible values are {cl, ph, eh, jc}
  • Actual Base64 encoded feature vector of the reference image. It can be obtained by calling LireFeature.getByteRepresentation() and by Base64 encoding the resulting byte[] data.
  • Optional maximum distance for those data items that cannot be processed, ie. don't feature the respective field.

Note that if you send the parameters using an URL you might take extra care of the URL encoding, ie. white space, the "=" sign, etc.

Examples:

  • [solrurl]/select?q=:&fl=id,lirefunc(cl,"FQY5DhMYDg...AQEBA=") – adding the distance to the reference image to the results
  • [solrurl]/select?q=:&sort=lirefunc(cl,"FQY5DhMYDg...AQEBA=")+asc – sorting the results based on the distance to the reference image

If you extract the features yourself, use code like his one:

// ColorLayout
ColorLayout cl = new ColorLayout();
cl.extract(ImageIO.read(new File("...")));
String arg1 = "cl";
String arg2 = Base64.encode(cl.getByteArrayRepresentation());

// PHOG
PHOG ph = new PHOG();
ph.extract(ImageIO.read(new File("...")));
String arg1 = "ph";
String arg2 = Base64.encode(ph.getByteArrayRepresentation());

Indexing

Check ParallelSolrIndexer.java for indexing. It creates XML documents (either one per image or one single large file) to be sent to the Solr Server.

ParallelSolrIndexer

This help text is shown if you start the ParallelSolrIndexer with the '-h' option.

$> ParallelSolrIndexer -i <infile> [-o <outfile>] [-n <threads>] [-f] [-p] [-m <max_side_length>] [-r <full class name>] \\
         [-y <list of feature classes>]

Note: if you don't specify an outfile just ".xml" is appended to the input image for output. So there will be one XML file per image. Specifying an outfile will collect the information of all images in one single file.

-n ... number of threads should be something your computer can cope with. default is 4. -f ... forces overwrite of outfile -p ... enables image processing before indexing (despeckle, trim white space) -m ... maximum side length of images when indexed. All bigger files are scaled down. default is 512. -r ... defines a class implementing net.semanticmetadata.lire.solr.indexing.ImageDataProcessor that provides additional fields. -y ... defines which feature classes are to be extracted. default is "-y ph,cl,eh,jc". "-y ce,ac" would add to the other four features.

INFILE

The infile gives one image per line with the full path. You can create an infile easily on Windows with running in the parent directory of the images

$> dir /s /b *.jpg > infile.txt

On linux just use find, grep and whatever you find appropriate. With find it'd look like this assuming that you run it from the root directory:

$> find /[path-to-image-base-dir]/ -name *.jpg

OUTFILE

The outfile has to be send to the Solr server. Assuming the Solr server is local you may use

curl.exe http://localhost:8983/solr/lire/update -H "Content-Type: text/xml" --data-binary "<delete><query>*:*</query></delete>"
curl.exe http://localhost:8983/solr/lire/update -H "Content-Type: text/xml" --data-binary @outfile.xml
curl.exe http://localhost:8983/solr/lire/update -H "Content-Type: text/xml" --data-binary "<commit/>"

You need to commit you changes! If your outfile exceeds 500MB, curl might complain. Then use split to cut it into pieces and repair the root tags (<add> and </add>)

LireEntityProcessor

Another way is to use the LireEntityProcessor. Then you have to reference the solr-data-config.xml file in the solrconfig.xml, and then give the configuration for the EntityProcessor like this:

<dataConfig>
    <dataSource name ="bin" type="BinFileDataSource" />
    <document>
        <entity name="f"
                processor="FileListEntityProcessor"
                transformer="TemplateTransformer"
                baseDir="D:\Java\Projects\Lire\testdata\wang-1000\"
                fileName=".*jpg"
                recursive="true"
                rootEntity="false" dataSource="null" onError="skip">
            <entity name="lire-test" processor="net.semanticmetadata.lire.solr.LireEntityProcessor" url="${f.fileAbsolutePath}" dataSource="bin"  onError="skip">
                <field column="id"/>
                <field column="cl_ha"/>
                <field column="cl_hi"/>
                <field column="ph_ha"/>
                <field column="ph_hi"/>
                <field column="oh_ha"/>
                <field column="oh_hi"/>
                <field column="jc_ha"/>
                <field column="jc_hi"/>
                <field column="eh_ha"/>
                <field column="eh_hi"/>
            </entity>
        </entity>
    </document>
</dataConfig>

Mathias Lux, 2015-01-14