Inclusion of Vertical Bar in the OMR Sheet for Image-Based Robust and Fast OMR Evaluation Technique Using Mobile Phone Camera

Abstract

Optical mark recognition (OMR) is a prevalent data gathering technique which is widely used in educational institutes for examinations consisting of multiple-choice questions (MCQ). The students have to fill the appropriate circle for the respective questions. Current techniques for evaluating the OMR sheets need dedicated scanner, OMR software, high-quality paper for OMR sheet and high precision layout of OMR sheet. As these techniques are costly but very accurate, these techniques are being used to conduct many competitive entrance examinations in most of the countries. But, small institutes, individual teachers and tutors cannot use these techniques because of high expense. So, they resort to manually grading the answer sheets because of the absence of any accurate, robust, fast and low-cost OMR software. In this paper, we propose the robust technique that uses the low-quality images captured using mobile phone camera for OMR detection that gives $100\%$ accuracy with less computation time. We exploit the property that the principal component analysis (PCA) basis identifies the direction of maximum variance of the data, to design the template (introducing the vertical bar in the OMR sheet) without compromising the look of OMR answer sheet. Experiments are performed with 140 images to demonstrate the proposed robust technique.