Imatest software can measure 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 and module […]

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 […]

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 […]

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 […]

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  Information capacity-related: Noise Power Spectrum (NPS), Noise Equivalent Quanta, SNRi, Object visibility. 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 […]

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

  The basic premise of this work is that Information capacity is a superior metric for predicting the performance of imaging systems. It is better than sharpness or noise, which it incorporates, and it can be used  to derive metrics for measuring object and edge detection performance and for designing electronic filters that optimize system performance.   Related pages Image Information Metrics: Information Capacity and more contains key links to documentation, white papers, news, and more on image information metrics. The Electronic Imaging 2024 paper, Image information metrics from slanted edges, contains the best exposition of the image information metrics. The […]

  The basic premise of this work is that Information capacity and related metrics for measuring edge and object detection performance are superior to familiar metrics (sharpness and noise) for predicting and optimizing the performance of imaging systems.   Related pages Image Information Metrics: Information Capacity and more contains key links to documentation, white papers, news, and more on image information metrics. The revised (August 2024) paper from Electronic Imaging 2024, Image information metrics from slanted edges, contains the most complete and up-to-date exposition of the image information metrics. The material is also covered in various levels of detail in the […]

  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 […]

Introduction – Test chart – Photograph the chart – Framing – Lighting  Distance – Exposure – Run Imatest – Select files – Settings – Warnings – clipping  Batchview (combined results) – Checklist  Testing lenses: Introduction Lens quality (especially sharpness) has always been of major interest to photographers. Traditionally, lens testing has been highly tedious, best left to professionals and large publications. With Imatest, that has changed forever. All you need to do is photograph an SFRplus, eSFR ISO, or tilted Checkerboard chart (with careful technique of course), run the corresponding module (SFRplus, eSFR ISO, or Checkerboard), and interpret the results. The three […]

Related web pages Using Color/Tone Interactive (Multicharts) – Interactive analysis of color & grayscale test charts Using Color/Tone Auto – Fixed (batch-capable) analysis of color & grayscale test charts Color/Tone / eSFR ISO Noise – including chroma, sensor (RAW), and visual noise Dynamic Range – a general introduction with links to Imatest modules that calculate it. Color Correction Matrix (CCM) Calculate a matrix (usually 3×3) for correcting image colors (often from RAW images)   Patch order In addition to linear step charts (which have a single row of patches), three Imatest modules— Stepchart, Color/Tone Interactive (formerly Multicharts), and Color/Tone Auto (formerly Multitest)— can analyze the tonal response and […]

Spanish language translation: Glosario en Espanol Aliasing   Low frequency artifacts, sometimes quite disturbing, that appear when the image sensor receives significant signal energy above the Nyquist frequency. Color aliasing in Bayer sensors can be particularly troublesome. “Moire fringing” is a type of aliasing. See diagram in Nyquist frequency, below. Controlled by means of Anti-Aliasing (Optical Lowpass) Filters, which blur the image slightly (a classic tradeoff).  Aperture   The circular opening at the center of a lens that admits light. Generally specified by the f-stop (f-number), which is the focal length divided by the aperture diameter. A large aperture corresponds […]

Imatest Glosario Par Pablo Ruiz Garcia Aliasing. Elementos de baja frecuencia, a veces muy molestos, que aparecen cuando la energía de la señal alcanza al sensor digital por encima de la frecuencia Nyquist. El efecto de flecos moire son un tipo de alilasing. Aberración cromática. Es una característica de la lente que provoca que las distintas longitudes de onda formen foco en distintos puntos. Existen dos tipos; longitudinal, donde los diferentes colores forman su foco en planos distintos. Y, lateral, donde la longitud focal de la lente, por lo tanto la ampliación, es diferente para cada color. La aberración cromática […]

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 […]

Gamma is the exponent of the equation that relates scene luminance with image pixel level. When the raw output of the image sensor, which is linear, is converted to image file pixels for a standard color space, the equation below is applied (very approximately, as we’ll explain below). pixel level = (RAW pixel level)gamma_camera ~= exposuregamma_camera      (1) When an image file is sent to a display (a monitor or print), Output luminance = (pixel level)gamma_display      (2) The total system gamma is gamma_camera * gamma_display.  Standard values of display gamma are 1.8 for older color spaces used in the Macintosh and 2.2 […]

Postprocessor for SFRplus, Checkerboard, and eSFR ISO for analyzing image quality factors that require multiple images: Curvature of field, Longitudinal (Axial) Chromatic Aberration, & more Introduction to FocusField FocusField is a postprocessor for displaying camera test results from batches of images acquired at different distances and/or with different focus settings (also with different apertures), then analyzed by SFRplus, Checkerboard, or eSFR ISO  batch runs. (These modules are preferred because magnification, and hence distance, can be derived from the image.) It can display Depth of Field (DoF), Curvature of field, Longitudinal (axial) chromatic aberration, and Lens focal length (when used with the motorized […]

Find the sharpest files in a batch Thanks for Andrea Nivini for suggesting this module. New in Imatest 5.2: A major redesign of Find Sharp Files. A summary plot is available. Results can be shown in an easy-to-read Table format. Results can be saved in CSV and JSON files.   Find Sharpest Files lets you quickly and conveniently rank the sharpness of a set of images. It works on any image— it doesn’t have to be a test chart. It runs much faster than any of the standardized sharpness measurements (slanted-edge, star, etc.). There are a number of situations where this capability […]