Electronic Imaging 2017

Imatest is pleased to announce that they will attend the 2017 IS&T Electronic Imaging conference from January 29 – February 2, 2017. Join us as we discuss, learn about and share the latest developments in electronic imaging technology. You can also email us to set up an appointment in advance.

Testing a macro lens using Checkerboard and Micro Multi-slide

Imatest’s Checkerboard module is our new flagship module for automated analysis of sharpness, distortion and chromatic aberration from a checkerboard (AKA chessboard) pattern. The big benefit of using the checkerboard is that there are looser framing requirements than with other kinds of test targets. While checkerboard lacks the color and tone analysis provided by SFRplus and eSFR ISO, these features are not available on the high precision chrome on glass substrate, so the checkerboard is the optimal pattern for this test.

Using Sharpness to Measure Your Autofocus Consistency

Autofocus plays a major role in many camera system applications with variable focus, including consumer electronic devices. Camera systems must be able to focus at a variety of distances. Optical systems on cameras only allow a certain range of distances from the camera to be in focus at once (this is often known as the depth of field, or depth of focus).

Contrast Resolution chart and analysis

Introduction Introduction – Background – The Contrast Resolution chart – Photographing & analyzing – Tonal response and SNR – Visualization – Analysis – Contrast Resolution Dynamic Range – Tone mapped results – Summary – Verification This page describes the Imatest Contrast Resolution chart and analysis (supported by Imatest 5.0+), which is designed to measure the visibility of low contrast objects in larger fields over a wide range of brightness. These measurements are expressed as the Contrast Resolution Signal-to-Noise Ratio (SNRCR) and Dynamic Range (DRCR). They are of particular interest to the automotive and security industries. This method of dynamic range measurement was inspired […]

Spilled Coins Cross Test Chart

The updated Imatest Spilled Coins Cross test charts use cross-correlation calculation texture metrics to provide improved stability for images with nonlinear noise reduction. Users can now more accurately differentiate between noise and texture. Random/Dead Leaves Cross, which runs under the interactive Rescharts interface, measures SFR (Spatial Frequency Response) or MTF (Modulation Transfer Function) from random scale-invariant (or approximately scale-invariant) test charts, including “Dead Leaves” and “Spilled Coins” charts.

Texture Analysis ( Random-Cross) Method

Introduction: Starting in version 4.5, Imatest is capable of performing the cross-correlation based texture blur measurement which is under consideration for ISO 19567-2: Texture Analysis on Stochastic Pattern. This is a texture-blur-analysis method originally proposed in Description of texture loss using the dead leaves target: Current issues and a new intrinsic approach by Kirk et al at Image Engineering.  This method starts from the same principles as the so-called “Direct” method of Cao et al which is the Power Spectral Density-based method described on the Random Module page. The main difference is the Direct method makes use of assumed statistical properties […]

Long Range Testing

For lenses that focus out at long distances, to verify ability to focus on distant objects you will need a target system that produces an image that is at or beyond the hyperfocal distance of your lens. You can use our chartfinder utility to determine the size of your imaging plane at a distance based on your lens’ angular field of view. Jump to: Collimator Fixture  |  IMTS Target Projection | IBTS Stray Light/Target Projector Version | Projection Collimators | Multi-collimator systems  | Physical Targets Virtual Target Projection Systems A collimator lens (also known as a close-up lens or relay lens) can change […]

Image Quality Factors

Image Quality Factors are also called Key Performance Indicators (KPIs). Sharpness Noise Dynamic-Range Color Accuracy Distortion Uniformity Chromatic Aberration Flare Color Moiré Artifacts Compression Links   Image Quality Factor Video Series   Summary table— Image quality factors and corresponding test charts and modules Sharpness   Noise   Dynamic range, tone, & contrast   Color accuracy Lens Distortion   Uniformity   Blemishes   ISO Sensitivity Lateral Chromatic Aberration   Lens Flare (Veiling Glare)   Color Moiré   Artifacts Data compression losses   Dmax   Color gamut    Texture Detail   Overview of image quality and Imatest measurements  Image quality is one […]

Artifacts

Noise reduction and sharpening           Original | NR+Sharpening Software (especially operations performed during RAW conversion) can cause significant visual artifacts, including oversharpening “halos” and loss of fine, low-contrast detail. These artifacts result from nonlinear (nonuniform) signal processing (so-called because it varies with the signal). Images may be sharpened (MTF boosted) in the proximity of contrasty features like edges and blurred (lowpass filtered) in their absence. This generally improves measured performance (both sharpness from slanted-edges and noise/Signal-to-Noise Ratio (SNR) from chart patches), but it may result in a degradation of perceived image quality, for example, a “plasticy” cartoon-like appearance of skin even […]

Ultra-wide Camera Testing

Resolution Testing Fisheye (highly barrel-distorted) lenses can be effectively tested with several Imatest modules. SFRplus with pre-distorted test charts. If chart parameters are entered, distortion and Field of View (FoV) are calculated. eSFR ISO with pre-distorted test charts. Distortion and FoV are not currently calculated. Beyond around 160° it becomes increasingly difficult to fill the image plane with a planar test chart.   We introduced SFRreg as a flexible target and analysis system for testing the resolution of ultra-wide cameras. (It can also be used for long-distance and depth of field testing) Example of an ultra-wide camera test setup: See […]

Lens Testing

The quality of a camera lens determines how an image forms on a sensor. Lens quality is tested to verify the lens is designed, built, and focused correctly. Once a highly tedious process, Imatest has since refined the testing practice with several solutions, including highly accurate and specific test charts and fixtures. Testing Distance – Sharpness – Chromatic Aberration – Lens Flare Geometric Calibration – Relevant Standards – Supply Chain Image Quality   Testing Distance To determine what size of test chart is needed, use the Imatest Chart Finder that can also calculate the imaging plane based on the sensor […]

ISO 15739 — Noise measurements

Standard: ISO 15739:2017 — Photography — Electronic still-picture imaging— Noise measurements Technical Committee: ISO/TC 42 Photography Published: 2017-05   The Simplified ISO-15739 digital camera noise test chart is available from the Imatest Store. This chart can be analyzed by the Imatest Stepchart, Multicharts, and Multitest modules.   Imatest 4.0+ includes a calculation of ISO 15739 visual noise as specified in Appendix B of the ISO 15739:2017 standard. And Imatest 4.4+ includes a calculation of visual noise from the IEEE CPIQ P1858 (Camera Phone Image Quality) 2016 specification, which is based on ISO 15739 with some added details. These are relatively complex […]

ISO 16505 — Road Vehicles — Camera Monitor Systems

  Standard: ISO 16505:2015 Road vehicles — Ergonomic and performance aspects of Camera Monitor Systems — Requirements and test procedures. Technical Committee: ISO/TC 22/SC 35 Lighting and visibility Published: 2015-05-01   Test Targets ISO 16505 Test Targets are available for purchase on the Imatest Store. Test Methods Resolution References ISO 12233:2014.   Hyperbolic wedge features can be analyzed by the Wedge or eSFR ISO module. Slanted edge features can be analyzed by the SFR, SFRplus, eSFR ISO, SFRreg, or Chekerboard modules. We presented a paper, “Measuring MTF with wedges: pitfalls and best practices” at the Multi-camera and Embedded Systems for Autonomous Machines […]

ISO 12233 — Resolution and spatial frequency responses

eSFR ISO: Analyze the ISO 12233:2017 Edge SFR chart* and ISO 12233:2023 Edge SFR chart   Standard: ISO 12233:2017 — Photography— Electronic still picture imaging — Resolution and spatial frequency responses* ISO 12233:2023 — Photography— Electronic still picture imaging — Resolution and spatial frequency responses Technical Committee: ISO/TC 42 Photography Published: 2017-01, 2023-02   This new standard defines three test charts. The new Imatest eSFR ISO module performs a highly automated analysis of the new low contrast (4:1) Edge SFR chart and is available in Imatest Master and Image Sensor 4.0.  * Note: ISO 12233:2014 has the same chart requirement.

Dynamic Range

Dynamic Range (DR) is the range of exposure, i.e., scene brightness, over which a camera responds with good contrast and good Signal-to-Noise Ratio (SNR). Related pages Veiling glare (lens flare)  describes several measurement techniques, including the new Contrast Resolution method. Contrast Resolution – A special transmissive chart for measuring the visibility of low contrast features in larger fields over a wide dynamic range Making Dynamic Range Measurements Robust Against Flare Light   Sensor vs. System DR – Flare, Charts, Exposure – DR definitions – Transmission chart – Lightbox How to measure DR – Overexposure – Minimizing reflections – Contrast Resolution chart Tips and recommendations […]

Imatest IT/.NET Instructions

How Imatest IT/.NET works Imatest IT/.NET (Industrial Testing .NET) is a Microsoft .NET Framework library that allows developers to access Imatest‘s powerful image quality analysis tools via calls to methods residing in a .NET DLL library. The library methods perform the same calculations as the corresponding GUI-based Imatest Master modules.  Imatest IT/.NET is compatible with .NET Framework versions 4.5 and higher.  Fourteen modules are available: SFR   SFRplus   Star Colorcheck   Stepchart   Wedge Uniformity (Light Falloff)   Distortion   eSFR ISO Blemish   Dot Pattern   Multitest OIS   Random     Imatest IT/.NET is a complete package that includes the module libraries, […]

Autofocus Speed

Imatest 4.4+ can evaluate auto-focus (AF) as a measure of MTF with respect to time. This can be performed by using the SFR module with an appropriate video file. Uses/Purpose This metric is intended to be used as a way to measure the time a camera system takes to auto-focus. Rise time and settling time are automatically calculated. This measurement does not provide information about the accuracy or precision of auto-focus. To evaluate those measures, several measurements should be performed on the final, settled images and compared. File Selection and Frame Selection Begin by clicking on SFR from the main window and select a […]

Image Processing

Operation – Image processing blocks – Displays and analysis – Optical Character Recognition (OCR) Face and People Detection The Imatest Image Processing module, introduced in Imatest 4.4 and significantly enhanced in 4.5 and 5.0, simulates a number of image processing operations, including image degradations such as noise and blurring as well as image enhancements such as applying a Color Correction Matrix, tone mapping (used in High Dynamic Range (HDR) imaging), Unsharp Masking (USM), and bilateral filtering. You can instantly observe the visible effects of these operations by switching between unprocessed and processed images. You can see how processing affects several measurements, including SSIM, PSNR, and MTF. […]

IEEE Camera Phone Image Quality (CPIQ) Support

  This page describes details about the implementation of our CPIQ Solution.   For additional details about the initiative, see this presentation assembled by former committee chair Margaret Belska.   Imatest’s CPIQ Implementation Imatest 4.4+  supports IEEE CPIQ P1858TM (Camera Phone Image Quality) 2016 measurements. As members of CPIQ, we are strongly committed to providing convenient CPIQ-compliant and equivalent image quality measurements. NOTE: You should use at least Imatest 4.4.9 for the latest corrections to visual noise calculations. This page has similar order to chapters the CPIQ Standard, “P1858TM/D1 Standard for Camera Phone Image Quality“ document. The first four chapters […]

Imatest IT Test Items & Modules

The Test Items below are oriented towards manufacturing and quality control. The Imatest Module list shows each relevant output. “X” indicates optimal support for the test item and “/” indicates sub-optimal support.   Sharpness Modules Test Item SFRplus eSFR ISO SFR SFRreg Random Log-f Contrast Wedge Star Sharpness (MTF) X X X X X X X X Limiting Resolution   X         X   Lateral Chromatic Aberration X X X X         Distortion X  /             Field of View X X             Tilt X […]