Similar image search by pHash distance in Elasticsearch

Question

Similar image search problem

• Millions of images pHash\'ed and stored in Elasticsearch.
• Format is \"11001101...11\" (length 64), but can be changed (

Answer 1

I have used @ndtreviv's answer as a starting point. Here are my notes for ElasticSearch 2.3.3:

1. es-plugin.properties file is now called plugin-descriptor.properties

2. You do not reference NativeScriptFactory in elasticsearch.yml, instead you create an additional class next to your HammingDistanceScript.

---

import org.elasticsearch.common.Nullable;
import org.elasticsearch.plugins.Plugin;
import org.elasticsearch.script.ExecutableScript;
import org.elasticsearch.script.NativeScriptFactory;
import org.elasticsearch.script.ScriptModule;

import java.util.Map;

public class StringMetricsPlugin extends Plugin {
    @Override
    public String name() {
        return "string-metrics";
    }

    @Override
    public  String description() {
        return "";
    }

    public void onModule(ScriptModule module) {
        module.registerScript("hamming-distance", HammingDistanceScriptFactory.class);
    }

    public static class HammingDistanceScriptFactory implements NativeScriptFactory {
        @Override
        public ExecutableScript newScript(@Nullable Map params) {
            return new HammingDistanceScript(params);
        }
        @Override
        public boolean needsScores() {
            return false;
        }
    }
}

3. Then reference this class in your plugin-descriptor.properties file:

---

plugin=com.example.elasticsearch.plugins. StringMetricsPlugin
name=string-metrics
version=0.1.0
jvm=true
classname=com.example.elasticsearch.plugins.StringMetricsPlugin
java.version=1.8
elasticsearch.version=2.3.3

4. You query by supplying the name you used in this line: module.registerScript("hamming-distance", HammingDistanceScriptFactory.class); in 2.

Hope this helps the next poor soul that has to deal with the shitty ES docs.