IJRSET 2015 SPL Volume 2, Issue 9 Pages: 29-36 1 A SURVEY ON MEDICAL IMAGES 1 Dr. S. Vimala, 2 B. N. Bobi Nath 1, 2 Department of Computer Science, 1, 2 Mother Teresa Women’s University, India. Abstract:- Medical Images play a major role in analyzing the abnormalities in human body. Modern medical instruments are able to produce different views of images which can be used for better diagnoses and accurate treatment. Processing of medical images using computers will help the medical experts to take right decision in right time to save human lives. In this paper, various formats of images based on storage in computers and the different types of medical imaging based on various medical applications are discussed. Medical imaging is the idea to improve the content of the images taken from different imaging tools like X-Rays, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), Ultrasound, Single Photon Emission Computed Tomography (SPECT), etc. The various types of Medical images, their advantages and disadvantages along with the format of medical images, their characteristics and the comparison of CT, MRI & Ultra sound imaging are discussed briefly in this paper. Keywords: - Medical Imaging, image types, image formats, X-Ray, CT, MRI, Ultrasound, PET, SPECT, DICOM. 1. INTRODUCTION "A Picture Worth Thousand Words", of course a complex scheme can be conveyed easily with just a single still image. Image processing has become inevitable in computers now-a-days. When working with computers, whether we need it or not, we are pooled with lots of images. An image when processed using computers is called a digital image. A digital image is an array, or a matrix, of square pixels (picture elements) represented using a set of bits (zeroes and ones). The set of bits is decided by a specific Digital Image Format [1]. There are two main categories of Digital Images - one is Vector Images and the other is Raster Images. The size of an image is determined directly from the width (number of columns) and the height (number of rows) of the image matrix I(r, c) [2]. Each value in the Image Matrix is called Pixel Value. An individual pixel depends on the type of image [2]. 1.1 DIGITAL IMAGE PROCESSING Image Processing is a technique to enhance raw images received from cameras/sensors placed on satellites, space probes and aircrafts or pictures taken in normal day-to-day life for various applications [4]. The term Digital Image Processing refers to processing of a two-dimensional picture by a digital computer [5]. Digital Image Processing concerns the transformation of an image to a digital format and its processing by a computer or by dedicated hardware [6] (both input and output are digital images). Image Processing is used in various fields such as: Remote Sensing, Medical Imaging, Forensic Studies, Textiles, Material Science, Military, Film industry, Document processing, Printing Industry, Industrial Inspection, Satellite Imaging, Telecommunication, etc.