Bilkent University
Department of Computer Engineering


Mobile Image Search Using Multi Image Queries


Fatih Çalışır
MSc Student
(Supervisors: Prof. Dr. Özgur Ulusoy, Prof. Dr. Ugur Güdükbay)
Computer Engineering Department
Bilkent University

Visual search has evolved over the years, according to the demand of users. Textbased visual search gives its place to content-based image search. Single image query search systems are inadequate to represent a query object, because they are limited to a single view of the object. Therefore, multi image query search systems have gained importance to increase search performance. Recent advances in mobile device technology transfer the image search to mobile platforms. Accessibility and ease of taking multiple photos with mobile devices has motivated us to develop a mobile image search system.

We propose a mobile multi-image search system that makes use of local features and bag-of-visual-words (BoVW ) approach. In order to represent the query object better, we combine multiple local features each describing a different aspect of the query image. Employing different features in search improves the performance of the image search system. Another contribution of our work is increasing the retrieval performance using multi-view query approach together with fusion methods. Using multi-view images provides more comprehensive representation of the query image. We also propose weighted fusion methods that calculate the weights from the database images. The proposed weighted fusion methods increase the precision of the image search. We also develop a new multi-view object image database (MVOD), with the aim of evaluating the performance impact of using multi-view database images. Multi-view database images from different views and distances increase the possibility to match the query images to database images. As a result, using multi-view database images increases the precision of our search system.

We compare our image search system with a state-of-the-art work in terms of average precision. In our experiments, we use single and multi image queries together with single viewed database. The results show that our image search system perform better with both single and multi image queries. We also performed experiments using MVOD database and show that using a multi-view database increases the precision.


DATE: 5 August, 2015, Wednesday @ 13:30