Nonuniformity Correction in grayscale and color chart modules

Imatest can correct for nonuniform illumination and lens response (vignetting) in Imatest modules that analyze grayscale and/or color charts, including Color/Tone Setup (formerly Color/Tone Interactive), Color/Tone Auto (formerly Color/Tone Auto), Colorcheck, and Stepchart. Nonuniformity correction involves reading and specifying a second image, taken from a flat-field target (plain gray or white) under identical conditions to the test image.  Note that the correction described in this page is not the same as nonuniformity correction for slanted-edge MTF measurements. Not also that Color/Tone Interactive (a highly interactive module) and Color/Tone Auto (a batch-capable fixed version of Color/Tone Interactive) are recommended for new […]

Log Frequency

Analysis of log frequency-varying charts Introduction Log frequency, which uses the Rescharts interface, measures the contrast of narrow bar or sine charts that increase logarithmically in spatial frequency. It also measures color Moiré (Imatest Master only). When the image pattern is sinusoidal (rather than a bar chart), contrast is equivalent to SFR or MTF. This method is more direct than the slanted-edge method, but less accurate and more susceptible to noise. A chart can be created by Test Charts and printed on a high quality inkjet printer. Log Frequency image (complete and cropped) The image above used to illustrate the […]

IT-DLL Instructions

How Imatest IT/DLL works Imatest IT/DLL (Industrial Testing DLL; formerly API/DLL) is a library that allows developers to access Imatest‘s powerful image quality analysis tools via calls to functions residing in a Dynamic Link Library. At the present time (in Imatest 4.4) it supports calls from C and C++ , .NET (including C# and VB.NET), and Python.  Support for LabVIEW is under development. DLL modules perform the same calculations as the corresponding GUI-based Imatest Master modules. Fifteen modules are available: SFR   SFRplus   Star   OIS Colorcheck   Stepchart   Wedge   Random Uniformity (Light Falloff)   Distortion   eSFR ISO   SFRreg […]

Log F-Contrast

Analysis of Log Frequency-Contrast charts New in Imatest 4.0  Automatic region is available with the revised version of the chart, which includes registration marks in the corners. Sharpness and Texture Analysis using Log F‑Contrast from Imaging-Resource compares the the effects of sharpening and noise reduction in several cameras using images downloaded from Imaging-Resource.com. Introduction Log F-Contrast (short for Log Frequency-Contrast; not in Imatest Studio) measures the effects of signal processing— noise reduction and sharpening— on imaging system performance using a chart that varies in spatial frequency on the horizontal axis (log frequency increases with x) and in modulation (i.e., contrast) […]

Documentation – Previous v2021.1

View Release Notes     For beginners: We recommend these web pages for getting started: Image Quality Factors and Using Imatest – Getting started. VIDEOS – Online training – Consulting – News    Index of the Table of Contents Offline documentation Download the website for offline view (with a web browser) Image Quality  IQ factors (KPIs) measured by Imatest, with links to detailed descriptions and instructions. Sharpness  Introductions to sharpness and sharpening; comparisons of different charts; chart quality limitations & how to overcome them Other IQ factors  Noise, SNR, Temporal noise, Dynamic Range (DR),  Chromatic Aberrations, Distortion, Veiling glare, Shannon […]

Using SFRplus Part 2

Running SFRplus (Interactive and Auto mode settings) Imatest SFRplus performs highly automated measurements of several key image quality factors using a specially-designed test chart. This document shows how to run SFRplus in Rescharts and how to save settings for automated runs. Part 1 introduced SFRplus and explained how to obtain and photograph the chart. Part 3 illustrates the results. New in Imatest 3.10 SFRplus settings can be updated by clicking Settings, SFRplus Auto settings in the Imatest main window without having to read an image file into Rescharts SFRplus Setup. New in Imatest 3.9 SFRplus can be run without including […]

IT-DLL Instructions

How Imatest IT/DLL works Imatest IT/DLL (Industrial Testing DLL; formerly API/DLL) is a library that allows developers to access Imatest‘s powerful image quality analysis tools via calls to functions residing in a Dynamic Link Library. At the present time (in Imatest 4.4) it supports calls from C and C++ , .NET (including C# and VB.NET), and Python.  Support for LabVIEW is under development. DLL modules perform the same calculations as the corresponding GUI-based Imatest Master modules. Fifteen modules are available: SFR   SFRplus   Star   OIS Colorcheck   Stepchart   Wedge   Random Uniformity (Light Falloff)   Distortion   eSFR ISO   SFRreg […]

Imatest with ON Semiconductor DevWare

Introduction This page illustrates how to use image acquisition with ON Semiconductor DevWare, which is a part of ON Semiconductor’s DevSuite. Imatest also supports other development systems. Load images directly from DevWare. This eliminates the need to capture images separately, store them, then load them individually into Imatest, dramatically improving productivity. Note: As of Imatest 5.0 image acquisition capabilities were added to Imatest Master and Imatest IS was discontinued. Learn more.  Download and Install Software To download Imatest Master software, go to www.imatest.com/products/imatest-master/ Download and open the self-extracting executable (Imatest-IS-3.n.exe). This will install Imatest and the Matlab Compiler Runtime (MCR), which is required for […]

Imatest IT/EXE instructions

How Imatest IT/EXE works Imatest IT/EXE (Industrial Testing EXE; formerly API/EXE) is a set of standalone programs initiated by DOS calls, which can be issued by a test system. The programs have the same functionality as the corresponding Imatest Master modules, but they operate without user intervention, making them suitable for use in automated testing systems. They are represented by the blue box in the lower right of the figure below. Imatest IT/EXE flow diagram The test system interacts with the IT/EXE programs through files specified in the DOS command line— primarily an image file and an INI control file […]

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, […]

Imatest IT Modules & Tests

Test Item   Imatest Module

Skype for Business Video Specification Support

Instructions and comments Under development We are updating this page for the latest Skype for Business Video Capture Specification, December 2016. An index of of the Skype/Lync specifications can be found on https://technet.microsoft.com/en-us/office/dn788953 This document contains instructions for using Imatest with the Skype for Business Video Capture Specification, which has two versions: personal solutions (Document Number: H100693) and conferencing devices (Document Number: M1023160), published December 2016. “Skype for Business V3.0” appears on a watermark, and 3.0 is indicated in the Revision History (Section 1). It also contains comments and suggestions for running Imatest. The Skype spec uses only a tiny […]

Three optical centers

Customers frequently want to know how we measure the optical center of the image (not to be confused with the geometrical center).  They may be surprised that we measure three, shown below in the 2D contour map, which is one of the options in Rescharts slanted-edge modules 3D & contour plots.  SFRplus contour plot for MTF50P, showing three optical centers: For a normal well-constructed lens, the optical centers are all close to the geometric center of the image. They can diverge for defective or poorly-constructed lenses. Center of MTF (Center of Sharpness) The center of MTF (or Sharpness) is the […]

Using direct image acquisition

Direct image acquisition allows images to be captured directly from a variety of devices without first being stored as files. It has several important applications. Introduction – Direct data reload for realtime analysis – Signal averaging By continuously reloading images, it can be used for realtime (or near-realtime) image analysis, where “realtime” means that analysis appears to be instant in the timeframe of human perception. It is especially valuable for focusing with slanted-edges (which can be analyzed faster than other MTF patterns) or with cropped areas of arbitrary images.   It is very useful for signal averaging — a technique […]

Real-time focusing with Imatest Master direct data acquisition

Speed up your testing with real-time focusing in Imatest Master 2020.2. Recent speed improvements allow for real-time focusing and allow users to analyze images from two types of sources: Direct image acquisition from a variety of devices, listed in detail in Supported image acquisition hardware for Imatest Master.  Image files listed in Image file formats and acquisition devices, Although the majority of images traditionally analyzed by Imatest have been from files (JPG, PNG, etc.), three modules, which can perform a majority of Imatest’s analyses, support direct data acquisition, and can be used for realtime analysis.

Wedge

Analysis of hyperbolic or trapezoidal wedge patterns with the Imatest Wedge and eSFR ISO modules Introduction Imatest Master and IS can analyze wedge patterns in two modules, both of which may be run from the interactive Rescharts interface or as fixed (batch-capable) modules. The Wedge module (described in this document) can analyze any arrangement of horizontal or vertical (but not diagonal) wedges, using manual region selection. The eSFR ISO module can analyze pairs of wedges on the Enhanced and Extended eSFR ISO charts (including the charts with extra wedges), introduced in April 2014. Region detection is fully automated. The user […]

Version Comparison: Studio vs. Master

Which version is right for you? Imatest 5.0:  All functions of Imatest Image Sensor have been incorporated into Imatest Master.   Imatest is available in several GUI (Graphic User Interface)-based versions. Studio, with everything individual photographers need to test their cameras and lenses. Studio is only available to individual photographers. Master, the full-featured industrial-strength version for engineers and scientists who develop and evaluate imaging systems. Acquire images directly from several manufacturer’s development systems. Images can be updated and analyzed in real time with the Rescharts, Multicharts, and Uniformity-Interactive modules. As of Imatest 5.0, Image Sensor (IS) has been discontinued. All […]

Using Test Charts

Create test charts for high quality inkjet printers Although we strongly recommend that customers purchase charts from the Imatest Store, the Imatest Test Charts module allows you to create test chart files for printing on high quality photographic inkjet printers. If you plan to print charts using this module, you should be skilled at fine printing and have a knowledge of color management to obtain optimum chart quality; otherwise we recommend purchasing charts at the Imatest Store. Disclaimer: Although we sell most of the charts generated by the Imatest Test Charts module, several variations are not available because (A) it’s […]

Using SFRreg, Part 3: Results

Imatest SFRreg performs highly automated measurements of sharpness (expressed as Spatial Frequency Response (SFR), also known as Modulation Transfer Function (MTF)) and Lateral Chromatic Aberration from images that contain registration mark patterns (circles that contain two light and two dark quadrants). This document illustrates SFRreg results. Part 1 introduced SFRreg and explained how to obtain and photograph the chart. Part 2 showed how to run SFRreg inside Rescharts and how to save settings for automated runs.   SFRreg results When calculations are complete, results are displayed in the Rescharts window, which allows a number of displays to be selected. The following […]

Using SFRreg, Part 2: Running SFRreg

Running SFRreg (Interactive and Auto mode settings) Setup window – ROI numbering – More settings – SFRreg target detection Auto mode settings – Warnings – Summary Imatest SFRreg performs highly automated measurements of sharpness (expressed as Spatial Frequency Response (SFR), also known as Modulation Transfer Function (MTF)) and Lateral Chromatic Aberration from images that contain registration mark patterns (circles that contain two light and two dark quadrants). This document shows how to run SFRreg in Rescharts and how to save settings for automated runs. Part 1 introduced SFRreg and explained how to obtain and photograph the chart. Part 3 illustrates the […]