Impact of Low Resolution on Image Recognition with Deep Neural Networks: An Experimental Study

• Published in: International journal of applied mathematics and computer science Vol. 28; no. 4; pp. 735 - 744
• Main Authors: Koziarski, Michał, Cyganek, Bogusław
• Format: Journal Article
• Language: English
• Published: Zielona Góra Sciendo 01.12.2018; De Gruyter Poland
• Subjects: Artificial neural networks; Classification; Computer vision; convolutional neural networks; deep neural networks; Human performance; Image classification; Image quality; image recognition; Image resolution; low resolution; Neural networks; Object recognition; State of the art; super-resolution
• ISSN: 2083-8492; 1641-876X; 2083-8492
• DOI: 10.2478/amcs-2018-0056

Due to the advances made in recent years, methods based on deep neural networks have been able to achieve a state-of-the-art performance in various computer vision problems. In some tasks, such as image recognition, neural-based approaches have even been able to surpass human performance. However, the benchmarks on which neural networks achieve these impressive results usually consist of fairly high quality data. On the other hand, in practical applications we are often faced with images of low quality, affected by factors such as low resolution, presence of noise or a small dynamic range. It is unclear how resilient deep neural networks are to the presence of such factors. In this paper we experimentally evaluate the impact of low resolution on the classification accuracy of several notable neural architectures of recent years. Furthermore, we examine the possibility of improving neural networks’ performance in the task of low resolution image recognition by applying super-resolution prior to classification. The results of our experiments indicate that contemporary neural architectures remain significantly affected by low image resolution. By applying super-resolution prior to classification we were able to alleviate this issue to a large extent as long as the resolution of the images did not decrease too severely. However, in the case of very low resolution images the classification accuracy remained considerably affected.