Overview

The ISO 12233 standard specifies methods for measuring the resolution and spatial frequency response (SFR) of digital cameras. First published in 2000, the current latest version is the 5th edition, released in 2024.

Standard Used:

ISO 12233 Photography— Electronic still picture imaging — Resolution and spatial frequency responses

Technical Committee:

ISO/TC 42 Photography

Principle

e-SFR Principle:

The device under test captures an image of a slanted straight edge. The slant of the edge creates different “phases,” forming an oversampled edge spread function to counteract the uncertainty introduced by the shift variance of the discrete pixel array on the sensor. Then, the first derivative of the edge spread function is calculated to obtain the line spread function, which is then subjected to a Fourier transform and its modulus is taken to yield the spatial frequency response.

How to Test?

Test Equipment

According to the requirements of the ISO 12233 standard, the equipment used for e-SFR testing includes: Vertical Multi-CCT Illumination Source, CP135 SFR Slanted Edge Test Chart, and RIQA Image Quality Analysis Software