Cellular Automata for Image Resizing - Cellular Automata in Image Processing and Geometry - page 24

Chapter 2
Cellular Automata for Image Resizing

Konstantinos Ioannidis, Georgios Ch. Sirakoulis, and Ioannis Andreadis

Abstract. During the last years, several methods have been applied to tackle the
image resizing problem. Most of these methods are derived from image interpola-
tion techniques for image enlargement. Among them, the edge-directed interpola-
tion methods succeed to preserve the edges of the low resolution image and produce
crisper results compared to the space invariant models. In this chapter, we present an
edge-directed method which exploits the simplicity and the inherent parallelism of
the Cellular Automata (CA) computational tool to generate high resolution images
from low resolution acquired images. This task is accomplished with the help of the
Canny Edge Detector so as to discriminate the edge regions from the homogenous
ones. Moreover, appropriate CA states and transition rules were designed to evolve
the CA, which, eventually, attempt to enhance the quality of the edge areas. The ori-
entation of the edge cells are considered in order to preserve effectively the edges of
the initial image. The presented experimental results in terms of PSNR values and
processing time demonstrate the effectiveness of the proposed method when com-
pared to well-known methods as well as its suitability, especially for systems with
low requirements specifications when further image processing is required.

2.1 Introduction

Today, digital images and video sequences are usually stored and transmitted in
compressed form using different standards resulting in huge amounts of image data
found in every place of modern cyberlife. To tackle this situation, image resizing
methods able to generate high resolution images from their low resolution versions
are applied. Nevertheless, image enlargement is a non-trivial process that involves
a trade-off between efficiency, smoothness and sharpness. As a result, efficient

Konstantinos Ioannidis · Georgios Ch. Sirakoulis · Ioannis Andreadis
Laboratory of Electronics, Department of Electrical and Computer Engineering,
Democritus University of Thrace, Xanthi, Greece
e-mail: {kioannid,gsirak,iandread}@ee.duth.gr