International Journal of Engineering Trends and Technology (IJETT) – Volume 45 Number4 - March 2017 ISSN: 2231-5381 http://www.ijettjournal.org Page 168 Content Based Image Retrieval: Concept and Methodologies SHREELA PAREEK 1, HARDWARI LAL MANDORIA 2 1 Student, Department of Information Technology, College of Technology, G.B Pant University of Agriculture and Technology 2 Professor, Department of Information Technology, College of Technology, G.B Pant University of Agriculture and Technology Pantnagar, Uddham Singh Nagar, Uttrakhand, India 1 pareekshreela@gmail.com 2 drmandoria@gmail.com Abstract Due to increase in digital trend the number of images to be stored in digital format has also increase.so text based image retrieval was facing many problems to overcome these challenges content based image retrieval came under consideration, searching and retrieving of images from large database can be done using content based image retrieval system. Image retrieval based on low level features like color, texture and shape is a wide area of research scope ,In this paper we focus on the whole concept of content based image retrieval system and discussed about some of the methodologies used by content based image retrieval system. Keywords Content based image retrieval, Wavelet Transform, Saliency model, BoF I. INTRODUCTION Due to the explosive growth of digital technologies Image retrieval has become key factor in various applications like digital libraries, historic research, finger print identification, medicine etc. Searching, Browsing and Retrieving images from huge image databases are done by Image Retrieval Systems or we can say Image retrieval is technique concerned with searching and browsing digital images from database collection. To search images, a user provides query terms of keyword and the system will return images similar to the query. Image retrieval systems are classified as concept-based or text-based and content-based image retrieval systems. In Text-Based Image Retrieval, images are indexed using Keywords, which means keywords are used as retrieval keys during search and retrieval. In Content Based Image Retrieval image content is used to search and retrieve digital images from huge collection of Dataset. II. CONTENT BASED IMAGE RETRIEVAL A Content Based Image Retrieval (CBIR) act as an interface between a high level system (the human brain) and a low level System (a computer). In a content based image retrieval, image content are used to search and retrieve digital images from the Huge set of database based on the automatically derived features or visual content such as color, texture, shape and edge. Fig 1. Basic Block Diagram of Content Based Image Retrieval System Figure 1 show the basic block diagram of content based image retrieval. Image features are extracted for both query image and images in the database. The distance (i.e., similarities) between the features vectors of the query image and database are then computed and ranked. The database images that have highest similarity to the Query Image Database Image Feature Extraction Similarity Matching Retrieved Image