Imatest SFR allows you to analyze and display several regions of interest (ROIs) in an image. Display options can be selected from three dropdown windows from the SFR settings window. Multi-ROI plots lets you choose the plot type: 1D or 2D; units in Cycles/Pxl, LW/PH (Line Widths per Picture Height), or LP/PH (Line Pairs per Picture Height).The 1D summary plots, which display results as a function of the distance from the image center, may be difficult to read for lenses that are poorly centered and hence have asymmetrical response. In most cases 2D summary plots are far more readable. 1D […]

* indicates that this field will be described in more detail at the bottom of this document (Much of the text at the bottom will be common to several ini file reference pages). For more information on how to use INI files in Imatest IT, we recommend the Imatest INI File Reference For Imatest IT, most of these entries don’t need to be entered. Many don’t affect Imatest IT results: they control interactive figure displays or figure output formats (figures are often not used in Imatest IT). Background Meaning Yellow Yellow background: Important to Imatest IT. Parameter and Description are […]

Imatest Rescharts slanted-edge modules perform highly automated measurements of several key image quality factors using specially-designed test charts. The user never has to manually select Regions of Interest (ROIs). This page covers results that are (mostly) not derived from the slanted-edges themselves, including Noise (best in eSFR ISO) Distortion  (differing detail in different modules; best with SFRplus and eSFR ISO. Described in detail here. Tonal response*  (no noise statistics for SFRplus) Color accuracy*  when used with an SFRplus, eSFR ISO, or SFRreg center charts that contain a color pattern Vanishing resolution, aliasing, and Moiré from Wedge patterns in eSFR ISO ISO sensitivity*  (Saturation-based and […]

Imatest Rescharts slanted-edge modules perform highly automated measurements of several key image quality factors using specially-designed test charts. The user does not need to manually select Regions of Interest (ROIs). This page covers results that are derived from the slanted-edges (i.e., not from grayscale, color, or wedge patterns). It also covers text output (CSV and JSON) files. Sharpness, expressed as Spatial Frequency Response (SFR), also known as the Modulation Transfer Function (MTF), can be displayed in several ways for individual edges or from the entire pattern, Lateral Chromatic Aberration Other results, not derived from slanted-edges are covered in Part 4. Noise (best […]

Introduction – Using raw files – Bayer raw and RCCC files – LibRaw demosaicing (for commercial raw files)  Bayer frequency units – DNG files – Rawview utility – Generalized Read Raw (for binary raw files)  Decompanding – Creating Synthetic raw images   The unprocessed digital output of an image sensor is called RAW image data. In this document, we sometimes refer to raw files from commercial cameras or development systems as Camera raw to distinguish them from Bayer raw files, which are standard monochrome image files that contain undemosaiced (Bayer) data. Imatest modules can analyze raw files directly or after demosaicing. Bayer […]

Automatic region detection in SFRplus and eSFR ISO tolerates moderate amounts of optical distortion (pincushion or barrel), but it has definite limits. In this page we describe special versions of SFRplus and eSFR ISO charts that can work (i.e., can be detected automatically) with highly barrel-distorted (“fisheye“) lenses, with fields of view up to around 160 degrees— which are used in a number of applications, particularly for automotive rear-view and sports cameras. Cameras with fields of view over 160 degrees— even approaching 360 degrees— can be tested with the SFRreg module, which uses multiple individual “registration mark” charts facing the […]

Although sharpness is an important image quality factor, a sharper lens is not always better. A lens can be too sharp for a sensor, resulting in disturbing visual artifacts. These artifacts, which include “stair-stepping” and moiré patterns (low frequency patterns that can be strongly colored), can appear because digital cameras— and all digitally sampled systems— have a maximum spatial frequency, called the Nyquist frequency, beyond which scene information cannot be correctly reproduced. Any information above the Nyquist frequency that reaches the sensor will be “aliased” to a lower spatial frequency, which can result in the artifacts described below. Sampling – Nyquist […]

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 […]

Published January 30 2015 By Henry Koren, with contributions by Norman Koren. Edited by Matthew Donato, Jackson Roland and Ty Cumby. Table of Contents 1. Introduction The quality of imaging systems in mobile devices plays an increasingly important role in consumer purchasing decisions. A mobile device that fails to deliver acceptable quality images can have an adverse effect on the consumer’s brand loyalty, whether or not the customer has returned it. Unless proper care is taken, raising camera quality standards can reduce manufacturing yield. This could damage a supplier’s profitability as well as endanger their ability to deliver the required […]

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 […]

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) […]

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 Pass/Fail Operation and Reference   Introduction Imatest can return pass/fail (P/F) results for applications (such as industrial camera testing) where they are required. Although pass/fail is primarily intended for Imatest IT (Industrial Testing; DLL and EXE), it works with GUI-based versions of Imatest (except for Studio), where the Pass/Fail monitor can be particularly useful for previewing the results of P/F threshold settings for Imatest IT.  Getting started – Summary – Pass/fail settings file – Pass/Fail Reference  Slanted-edge (SFRplus, etc.) settings – Sharpness (Random and Star) – Blemish and Uniformity  Colorcheck – Distortion – Color/Tone – Stepchart  Getting started with […]

A pattern on an LCD screen may be used for SFR measurements using a pattern generated by the Imatest Screen Patterns module, which has several patterns to choose from. These patterns are convenient, but somewhat limited in usefulness because an LCD screen can only cover a fraction of the image frame, hence you can’t produce a good map the camera’s MTF response. Screen Patterns The Screen Patterns module is opened by clicking on Screen Patterns on the right of the Imatest main window. When it first comes up, it is completely blank (for use with Light Falloff). Select SFR: Quadrants […]

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, […]

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 […]

Test Item   Imatest Module

  Introduction Watch on YouTube. Imatest IT (Industrial Testing) is a set of Application Programming Interfaces (APIs) that allow developers to access Imatest’s powerful image quality analysis tools in their own custom applications. Imatest IT is available for 64-bit Windows, MacOS and Linux, and includes libraries for use with C, C++, Python, Objective-C, .NET (Windows only – including C# and Visual Basic), and LabVIEW. IT also contains standalone executables that can be called from a command line or script. The API libraries perform the exact same calculations as the corresponding GUI-based Imatest Master modules. Imatest IT is a complete package […]

Introduction This page briefly illustrates how to use the Imatest with Omnivision OVTAPantherM. Please note that Omnivision cameras are not supported in the macOS and Linux version of Imatest. However, Imatest supports other development systems to varying degrees. Contact us for details. Load images directly from Omnivision sensors. This eliminates the need to capture images separately, store them, then load them individually into Imatest, dramatically improving productivity. Download and Install Software To download Imatest software, go to store.imatest.com/software.html Download and open the Imatest Master self-extracting executable. This will install the Imatest Master edition and the Matlab Compiler Runtime (MCR), which is […]

This page is a reference for the INI files used to store Imatest settings, particularly imatest-v2.ini, which is the basis of ini files used to control Imatest IT. It focuses on INI file settings that are used by several modules and are of interest to users of Imatest IT and the Functional Interface.  INI file structure – Extracting an INI file for IT – Running from a Custom File – INI File Monitor – [api] (for Imatest IT) [LibRaw] – [rdraw] (Generalized Read Raw) – Secondary Readouts – Miscellaneous To keep this document to a reasonable length, the INI references for Imatest IT modules are stored […]