Merge pull request #4 from jlareck/images-documentation

Add documentation to the images dataset

databus-poms/dbpedia/generic/images/images.md

@@ -0,0 +1,33 @@
+# Images dataset
+contains URLs and basic metadata about images included in Wikipedia articles
+
+The dataset uses several properties to specify the relation between image entities and DBpedia entities.
+`dbo:thumbnail` connects the first image from the wikipage as thumbnail (donwload url width parameter set to 300 pixels) to the DBpedia entity. 
+In contrast, `foaf:depiction` connects the URLs of all images (no information on the order of appearance is given) in full size to a DBpedia entity.
+
+However, `foaf:thumbnail` is used to connect the thumbnail URL to the image entity. The subject of the image entity is the download / export API link and uses  
+ `rdf:type`, `dc:rights` for basic metadata.
+
+
+Examples of triples:
+
+```
+#DBpedia entity
+<http://dbpedia.org/resource/Joe_Biden> <http://xmlns.com/foaf/0.1/depiction> <http://commons.wikimedia.org/wiki/Special:FilePath/Joe_Biden_presidential_portrait.jpg> .
+<http://dbpedia.org/resource/Joe_Biden> <http://dbpedia.org/ontology/thumbnail> <http://commons.wikimedia.org/wiki/Special:FilePath/Joe_Biden_presidential_portrait.jpg?width=300> .
+
+# Image entities
+<http://commons.wikimedia.org/wiki/Special:FilePath/Joe_Biden_presidential_portrait.jpg> <http://xmlns.com/foaf/0.1/thumbnail> <http://commons.wikimedia.org/wiki/Special:FilePath/Joe_Biden_presidential_portrait.jpg?width=300> .
+<http://commons.wikimedia.org/wiki/Special:FilePath/Joe_Biden_presidential_portrait.jpg> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Image> .
+<http://commons.wikimedia.org/wiki/Special:FilePath/Joe_Biden_presidential_portrait.jpg> <http://purl.org/dc/elements/1.1/rights> <http://en.wikipedia.org/wiki/File:Joe_Biden_presidential_portrait.jpg> .
+
+# Thumbnail entities
+<http://commons.wikimedia.org/wiki/Special:FilePath/Joe_Biden_presidential_portrait.jpg?width=300> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Image> .
+<http://commons.wikimedia.org/wiki/Special:FilePath/Joe_Biden_presidential_portrait.jpg?width=300> <http://purl.org/dc/elements/1.1/rights> <http://en.wikipedia.org/wiki/File:Joe_Biden_presidential_portrait.jpg> .
+
+```
+
+
+### Changelog
+
+* [2021.12.01] Fixed producing image triples from pages that don't contain images. Fixed extracting images that are not related to the wikipages (Commits: [5b984fc7](https://github.com/dbpedia/extraction-framework/commit/5b984fc7d9f61822a9b017b85f6b2546c15e1370), [5b984fc](https://github.com/dbpedia/extraction-framework/commit/5b984fc7d9f61822a9b017b85f6b2546c15e1370), [ebc6c61](https://github.com/dbpedia/extraction-framework/commit/ebc6c6184679cfdea0c1648bae593a580dd8d7cc)). Related issue: https://github.com/dbpedia/extraction-framework/issues/720

databus-poms/dbpedia/generic/images/pom.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <groupId>generic</groupId>
+        <artifactId>group-metadata</artifactId>
+        <version>2016.10.01</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>generic</groupId>
+    <artifactId>images</artifactId>
+    <packaging>jar</packaging>
+
+    <properties>
+        <databus.codeReference>https://github.com/dbpedia/extraction-framework/blob/master/core/src/main/scala/org/dbpedia/extraction/mappings/ImageExtractorNew.scala</databus.codeReference>
+    </properties>
+
+</project>