MTFCalculator – A Mobile Application for Measuring the Modulation Transfer Function of Built-in Cameras of Smartphones Using ISO 12233 Slanted-Edge Method

The Modulation Transfer Function (MTF) is the most commonly used measure to test the performance of optical systems. A reliable and least complex method to find the MTF is by using the slanted-edge target, an ISO 12233 standard for measuring the quality of image capturing devices. The computation of MTF is a multi-step process, in which the three main components are the Edge Spread Function (ESF), the Line Spread Function (LSF), and the MTF. This paper presents the development of a mobile application to measure the MTF50 values to assess the performance of built-in smartphone cameras. The mobile application allows users to measure the quality of their smartphone cameras directly on their mobile phones, without the need to operate any heavy and complex desktop applications. Experiments have been performed using six different smartphones, including, Huawei Mate 10 Pro, Huawei P20 Pro, iPhone XS Max, iPhone 11, iPhone 11 Pro, and JiaYu S3. The experimental results are compared with Imatest, which is one of the most leading tools for testing the performances of imaging devices. The results of both the applications are exactly the same in terms of ranking the smartphones according to their MTF50 values.