原型基于颜色的图像检索与MATLAB

Prototyping Color-based Image Retrieval with MATLAB® Petteri Kerminen1, Moncef Gabbouj2

1Tampere University of Technology, Pori, Finland 2Tampere University of Technology, Signal Processing

Laboratory, Tampere, Finland

Abstract

Content-based retrieval of (image) databases has become more popular than before. Algorithm develop-ment for this purpose requires

testing/simulation tools,but there are no suitable commercial tools on the market.

A simulation environment for retrieving images from database according histogram similarities is presented in this paper. This environment allows the use of different color spaces and numbers of bins. The algorithms are implemented with MATLAB. Each color system has its own m-files.

The phases of the software building process are pre-sented from system design to graphical user interface (GUI). The functionality is described with snapshots of GUI.

1. Introduction

Nowadays there are thousands or hundreds of thousands of digital images in an image database. If the user wants to find a suitable image for his/her purposes, he/she has to go through the database until the correct image has been found or use a reference book or some “intelligent” program. Video on demand (VoD) services also requires an intelligent search system for

end-users. VoD systems’ search methods differ slightly from image database’s methods.

A reference book is a suitable option, if the images are arranged with a useful method, for example: 1)categories: animals, flags, etc, 2) names (requires a good naming technique) or 3) dates. An experienced user can use these systems as well as textual searches (keywords have to be inserted in a database) efficiently. There are situations when a multi-language system has to be used. There a language independent search system’s best properties can be utilized. A tool which is based on the images’ properties can be made

language independent. These properties can be for example color, shape, texture, spatial location of shape etc.

In the MuVi-project [1] this kind of tool is under construction. It will cover the properties presented above.Research work on content-based image retrieval has been done in [2 – 6]. The system, which is presented in this paper, is a simulation environment, where MuVi’s color content based retrieval has been developed and tested.

2. System development

MATLAB is an efficient program for vector and matrix data processing. It contains ready functions for matrix manipulations and image visualization and allows a program to have modular structure. Because of these facts MATLAB has been chosen as prototyping software.

2.1 System design

Before any m-files have been written, the system designhas been done. A system design for the HSV (hue, saturation and value) color system based retrieval process is presented in Figure 1. Similar design has been done for all used color systems.

Figure 1: Function chart for HSV color space with 27 bins histogram.