ISO 12233 Camera Resolution Measurements
ISO/TC 42 has revised ISO 12233, now ISO 12233:2014, Photography -- Electronic still picture imaging -- Resolution and spatial frequency responses, with methods for measuring the resolution and the Spatial Frequency Response (SFR) of digital cameras.
The first edition, issued in 2000, provided a scientifically sound and easily accomplished standard way to measure the true optical resolution performance of any digital camera image of the test target shown above. The protocols in this standard debunk the use of pixel count (megapixels) as a representation of camera resolution.
iso 12233 resolution chart
Spatial frequency response (SFR) refers to the use of a slanted-edge gradient technique for capturing a super-resolution edge profile and transforming this into a spatial frequency signature. This approach greatly enhances imaging performance diagnostics to measure lens blur, sharpening and potential aliasing.
Hyperbolic wedge refers to features on the resolution test chart for quickly and more reliably assessing the limiting optical resolution visually. Rather than using a traditional radial grating feature (for example a starburst pattern) in which line spacing increases linearly with distance, the line spacing of a hyperbolic wedge increases linearly with spatial frequency. This effectively stretches high-frequency regions, to enable more precise resolution assessment.
ISO 12233 has been revised by ISO TC 42/WG 18. Notable enhancements in the second edition include:
* Methods for Measuring SFR and Resolution – Selection Rationale and Guidance
* Low-contrast edge features for more stable slanted-edge SFR results
* A sine wave-based Siemens star SFR approach
* Objective measurement software tools for measuring visual resolution using the hyperbolic wedge feature.
Resolution test chart is the standard proof which can provide aided testing for vertical resolution and horizontal resolution of actual shooting.
Resolution test uses ISO 12233 resolution test chart and adopts unified shooting angle and environment.
The calculation of resolution test uses HYRes software, and the calculation will be done in two parts: vertical resolution and horizontal resolution.
Digital camera assessment is different from other products. It’s unlike laptop and DIY which have a lot of software to test objective data and everything can be seen from the data. However, assessing the quality of digital camera not only needs certain objective data, but also needs to combine actual operation and the shooting proofs. Therefore, our assessment is based on the principle of objective data and combined rational analysis from the experienced reviewers to obtain the most objective assessment results.
ISO 12233 resolution test chart is in accordance with ISO 12233 standard “Photography- Electronic Photographic Image-Measurement”. In active area of 1x size, the error is only 0.1mm when measuring the height of 20cm. It has almost all the characteristics of most resolution charts.