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/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 […]

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, […]

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 […]

These posts describe several topics, including: SFRplus Quadrant analysis (it includes the center region as well), Saturation analysis, which attempts to estimate the severity of saturation in slanted-edge regions (ROIs), and a few other recent additions (November 2012). Saturation is important because saturated light or dark regions will result in artificially high MTF readings. How to select regions at a fixed distance from center to corner (typically in the range of 65-85%)

Imatest software can measure a great many digital camera image quality factors from test chart images. If you’re just getting started we recommend that you explore: Image Quality factors page and IQ Testing for Beginners. The two most popular charts types/analysis modules are SFRplus and eSFR ISO, These allow users to measure a great many image quality factors from single test chart images.  Other modules and charts let you meet a wide variety of testing challenges.   Links to Content on this page: The Imatest workflow – Download & trial – Questions – Interactive vs. Fixed modules  Selecting the chart […]

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 […]

Introduced in Imatest 4.2, the Imatest Educational Apps serve to demonstrate mathematical concepts that directly relate to the understanding of image quality factors. The Imatest Educational Apps demonstrate Nyquist sampling theorem, the decomposition of an image’s Fourier transform, the Modulation Transfer Function of a slanted edge, chromatic aberration and signal to noise ratio (SNR). As an educational resource, this utility is available through the main window of your Imatest software. To access the Imatest Educational Apps, go to the Imatest main window and select Help, then Educational Apps…. A Welcome splash screen will open by default. Select the tabs across […]

Starting with Imatest 3.9, Imatest provides strong support for CPIQ (Camera Phone Image Quality)* Phase 2 measurements. Further detail is available in the CPIQ 2.0 Specifications & Test Methods document. Contact us if you need further information. We are members of CPIQ, and we will will add updated measurements as they become available (expected in early 2016). *CPIQ formerly belonged to I3A (International Imaging Industry Association). It now belongs to the IEEE Standards Association, Working Group P1858. SFR and Acutance For CPIQ, sharpness is measured as Spatial frequency response (SFR) (also called Modulation Transfer Function (MTF)). The SFR, SFRplus ( […]

News:  Imatest 2021.2  1D Fourier spectrum plots have been added to Cross-sections. QR or bar codes can be read in the Rectangle analysis.   Image Statistics is an interactive utility that lets you examine a number of image properties, including Vertical and horizontal cross-sections with adjustable thickness. Using a larger thickness mitigates the effects of noise. Pixel levels or 1D Fourier spectra can be plotted. Properties of rectangular or square (eyedropper) regions, including rectangle position, Mean values of R,G,B, and Y (luminance) channels, Log10(mean/max), Noise (sigma), Noise corrected for nonuniformity, SNR (Signal/Noise), SNR dB, and Mean L*a*b* (when color space has […]

Introduction The Imatest Image Stabilization/Sharpness Compare module is a postprocessor for SFRplus that Measures the effectiveness of Optical Image Stabilization (abbreviated as IS or OIS) by comparing the sharpness (MTF or related lengths) of selected near-horizontal and near-vertical edges from three similar SFRplus images: Unshaken. Shaken without Image Stabilization. (Some recent cameras lack the ability to turn IS off. There are several approaches to measuring IS effectiveness in this case. One is to have a very precise vibratory apparatus with known vibration angles. Expen$ive. Another is to substitute a camera with similar pixel configuration and lens focal length, but no […]

Operation – Image processing blocks – Displays and analysis – Remosaicing – 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 […]

Overview and introduction to measurements   Summary table— Image quality factors and corresponding test charts and modules Sharpness Noise Tonal response & contrast Color accuracy Lens Distortion Light Falloff & Nonuniformities Blemishes Dynamic range  Lateral Chromatic Aberration Veiling Glare Color aliasing and moiré Exposure accuracy     ISO Sensitivity   Focus & defocus   Data compression losses Texture Detail Information capacity  Software artifacts  Overview and Imatest measurements  Image quality is one of those concepts that’s greater than the sum of its parts. But you can’t ignore the parts if your goal is to produce images of the highest quality. Every image […]

Overview Why Imatest?     |     Test Charts     |     Lighting     |     Image Capture Technique     |     Setting up Your Lab     |     Using Imatest Software If you are getting started with Imatest — or need a good reference on using it — we recommend Imatest Instructions– Getting started. Why Imatest? Introduction Imatest charts and software allow you to measure the characteristics and quality of cameras and imaging systems. To begin measuring the resolution or color of your camera, you’ll need an image of a test chart. Imatest offers all-in-one test charts that can test […]