IMPLEMENTATION OF MATLAB-BASED DIGITAL IMAGE ROTATION ALGORITHMS TO IMPROVE VISUAL QUALITY AND IMAGE TRANSFORMATION PRECISION Implementasi Algoritma Pemutaran Citra Digital Berbasis MATLAB untuk Peningkatan Kualitas Visual dan Presisi Transformasi Gambar Section Articles

Abstract

Image rotation is a fundamental process in digital image processing used to change the orientation of
an image based on a specified angle around its center point. This transformation is widely applied in
various fields such as computer vision, medical imaging, object detection, biometric security systems,
and augmented reality technologies. This research aims to implement and analyze the performance of
image rotation algorithms using MATLAB by comparing three interpolation methods: nearest
neighbor, bilinear, and bicubic. The experiments were conducted at rotation angles of 30° and 45°, evaluated using computational time, Peak Signal-to-Noise Ratio (PSNR), and Mean Squared Error (MSE). The results indicate that the
nearest neighbor method offers the fastest computation time but yields lower image quality, reflected
by lower PSNR values and higher MSE. Meanwhile, the bilinear and bicubic methods produce
significantly better visual quality with higher PSNR, particularly bicubic, although they require longer
computation time. The MATLAB implementation using the imrotate function demonstrates that the quality of image
rotation strongly depends on the interpolation method used. These findings provide valuable insight for
researchers and practitioners in choosing the appropriate rotation method based on their needs—
whether prioritizing speed or quality. The provided MATLAB script serves as a reference for further
research and educational use in digital image processing.
Keywords: image rotation, MATLAB, PSNR, MSE, digital image processing