Metadata Collection for Personal Multimedia Repositories Using GWAP

With the increasing number of personal albums and photos in them, users have more and more problems with their organization [4]. This is due to lack of descriptive data, however, their amount only depends on the abilities and will of the image owners. Tools for metadata creation are available – the main problem is with the user motivation: because tagging and annotating of photos is usually a boring activity and its execution takes extended time periods. Other methods for obtaining metadata to general images also exist (automated methods, crowd-based, games with a purpose [1]), but these are unable to deliver specific metadata needed for personal imagery. Our aim is to create a method to enrich personal photo albums with keywords and also named entities. To achieve this, we use tool that imports personal albums, allows creating annotations using a GWAP, extracts keywords and named entities from annotations and allows browsing in albums using obtained metadata. Earlier, we devised a game with a purpose called PexAce [2, 3] for harvesting textual annotations to general images. Earlier experiments showed that people playing with their own photos are more engaged to game and also interested in creating annotations. By merging our game with automatic approach of metadata acquisition from game-produced annotations, we found an appropriate solution for creating metadata for personal photo albums. The main contribution of this work is a framework for processing annotations written to personal photos. This framework is based on metadata extraction modules called extractors and is extensible from this perspective. Inputs of all extractors are following five entries: photo, album to which photo belongs, user who created the annotation, annotation, and timestamp. In addition to these information, extractors have access to all logs saved during games and use them to refine results of annotation processing. Extractors are divided to two groups depending on their output. While the first group includes extractors extracting