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 in boldface. [IT] Cyan Cyan background: Figure settings. (Figures are used infrequently for IT.) [f] Gray Gray background: For interactive operation. No effect on IT. Clear Clear background: Results details (units, scaling, etc.) […]

Lens aberrations, diffraction, and defocus (or focus error) are basic factors that limit lens sharpness. They are described in the following sections. Lens aberrations – Diffraction – Pixel response limits and Q – Visualizing Q – Defocus  Lens (Optical) Aberrations Imperfections in optical systems arise from a number of causes that include different bending of light at different wavelengths, the inability of spherical surfaces (or even ashperes) to provide clear images over large fields of view, changes in focus for light rays that don’t pass through the center of the lens, and many more (i.e., coma, stigmatism, spherical aberration, and […]

In January 2013 Imatest released the Spilled Coins test chart, which is an improved version of the Dead Leaves chart for measuring a camera’s fine texture response. (It’s available in the Imatest Store in both monochrome and color versions.) Shortly afterwards, Jason Cope of our partner company Image Quality Labs found an anomalous result and called me to find out what was wrong. When I looked at the image I realized that he’d done the test correctly. He had found an image whose processing defeated the intent of the dead leaves chart, which is to accurately measure a camera’s texture […]

Tables to help you navigate Imatest modules and charts Imatest is a complex, rich application involving a great many image quality factors, modules, and test charts. The tables below, for Quality Factor, Module, and Test chart are designed to help navigate the site. A Table of contents is also available. Image quality factors – Modules – Test charts – Test images  Algorithms – Suppliers Image quality factors Image quality factors have their own page. A brief list of recommended test charts is given in the FAQ. Quality factor Charts Module Comments Camera, lens Color accuracy X-Rite ColorChecker (24-patch) Colorcheck, Color/Tone […]

Related pages Dynamic Range  a comprehensive introduction: strongly affected by flare light. Veiling glare (lens flare)  describes several measurement techniques, including the new Contrast Resolution method. Making Dynamic Range Measurements Robust Against Flare Light         Introduction – Background – The Contrast Resolution chart – Photographing & analyzing – Tonal response and SNR – Visualization – Visual analysis – Contrast Resolution Dynamic Range – Tone mapped results – Flare Mask & two-image measurement – Summary – Verification – References    Introduction This page describes the Imatest Contrast Resolution chart and analysis (supported by Imatest 5.0+), which is designed to measure […]

including raw (image sensor), chroma, and visual noise as well as several types of Dynamic Range calculation 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 Dynamic Range – a general introduction with links to Imatest modules that calculate it. Noise in Photographic Images – a basic introduction Color Correction Matrix (CCM) Calculate a matrix (usually 3×3) for correcting image colors (often from RAW images)   Color/Tone Setup (formerly Multicharts: Imatest ‘s interactive module for measuring most well-known color and grayscale charts), Color/Tone Auto (formerly Multitest: the batch-capable […]

Introduction  |  Measurement  |  Modules  |  Demosaicing Purple fringing – CA correction for non-tangential edges Introduction Chromatic aberration (CA) is one of several aberrations that degrade lens performance. (Others include coma, astigmatism, spherical aberration, and curvature of field.) It occurs because the index of refraction of glass varies with the wavelength of light, i.e., glass bends different colors by different amounts. This phenomenon is called dispersion. It appears as color fringing, most visibly on tangential edges near the boundaries of the image. It is sometimes confused with another effect, which we call pixel shift— a color channel offset that is […]

Obtain and photograph chart –  Lighting – Distance – Exposure – Tips – Links Imatest Checkerboard performs highly automated measurements of sharpness (expressed as Spatial Frequency Response (SFR), Lateral Chromatic Aberration, and optical distortion from images of checkerboard patterns (with a recommended tilt angle of ~5-8 degrees for sharpness measurements). The primary advantages of Checkerboard are: Compared to Imatest’s other automatically-detected sharpness modules:  It is relatively insensitive to framing. You can zoom in or out as much as you like, as long as there are detectable corner features.  Compared to the Distortion (legacy) module:  It works with highly-distorted (fisheye lens) images. Calculations are more accurate, and it contains all results […]

For more information on how to use INI files in Imatest IT, we recommend the Imatest INI File Reference This document was created by running checkerboard in Imatest 5.2.0. ALPHA on 30-May-2019 22:57:20. 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 in boldface. [IT] Cyan Cyan background: Figure settings. (Figures are used infrequently for IT.) [f] Gray Gray background: For […]

Imatest 5.1 has important new capabilities for measuring and correcting MTF degradation caused by test charts. These new capabilities are far easier to understand and apply than CQI. Chart quality calculator Compensating camera MTF measurements for chart and sensor MTF As a result of the improved measurements, the Chart Quality Index measurement has been deprecated. The Chart Finder is an interactive web page that can help you select the appropriate chart size and media. It contains results from this page, but without the math. Summary In order to determine the suitability of a test chart is for measuring the performance of a […]

Imatest lets you use the measured test chart modulation transfer function (MTF) to Determine the suitability of a test chart, which is characterized by size (height), print media, and printing technology, for camera MTF measurements where the camera is characterized by the number of vertical pixels. This can help determine whether a test chart is appropriate for a specific application.  Increase the accuracy of MTF measurements by dividing the measured camera MTF by the chart MTF projected on the image sensor. This is equivalent to deconvolution in spatial domain. This technique is described in Compensating camera MTF measurements for chart and […]

Postprocessor for viewing summaries of SFR, SFRplus, Checkerboard, and eSFR ISO results News — Imatest 25.1 (available in an alpha version before it is released)  Batchview has been significantly upgraded and refreshed. JSON files can now be used as input, in addition to CSV. Files can be combined for easier comparison between different groups of results. Automatic scaling (local or global for multiple images) is much more robust. Manual scaling should be unnecessary. Several results have been added, most importantly information metrics C_4, C_max, SNRi, and Edge Location standard deviation (σ). The y (vertical) axis can be logarithmic, as well […]

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. Related pages Auto Exposure in Stepchart Autofocus Speed in SFR Auto White balance in Colorcheck 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 […]

Analyses & Output – INI settings – Chart Definition Files – Chart Definition Utility – Video Analysis   INI file fields relevant to Arbitrary Charts The following INI fields are currently exposed to the user to control the behavior of the Arbitrary Charts module and its output. They have been organized here by topic, but do not need to be in any particular order or grouping in your INI file itself.    [arbcharts] section Slanted-edge Analysis     Texture Analysis   Star Analysis   Wedge Analysis   Uniformity Grid Analysis   Color/Tone/Noise   Circle Detection   Perceptual metrics   Video Analysis   […]

Analyses & Output – INI settings – Chart Definition Files – Chart Definition Utility – Video Analysis   Combine all the features you need to analyze into a single chart Introduction The Imatest™ Arbitrary Charts module analyzes images of custom test charts. A chart-definition file (typically user defined) is needed to describe the chart layout to Imatest software. The Arbitrary Charts module will automatically locate and analyze target features when an observed image of a chart is loaded along with the corresponding definition file.    This module allows users to get a number of measurements out of custom, legacy, or competitors’ charts which […]

Introduction to Acutance and SQF   Acutance and Subjective Quality Factor (SQF) are measures of perceived print or display sharpness. SQF was used for years in the photographic industry but has remained unfamiliar to most photographers. Acutance is a relatively new measurement from the IEEE Camera Phone Image Quality (CPIQ) group. Both are metrics which incorporate the effects of The imaging system: The Modulation Transfer Function (MTF) of the camera as a measurement of its intrinsic sharpness. The viewer: The human eye’s sensitivity to each spatial frequency modeled with a Contrast Sensitivity Function (CSF). The viewing conditions: The image display height […]

View Release Notes   For beginners: We recommend these web pages for getting started: Introduction to the new Imatest Main Window (New in 2021.2) Image Quality Factors – Using Imatest – Getting started – Imatest Updates and Features  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 […]

Join us and other automotive imaging industry experts on October 8-10 in Barcelona, Spain. We will present our advanced testing methods and algorithms for validating the quality of automotive cameras. Passes are free for OEM & Tier 1 Automotive industry companies or register for early bird pricing by August 23rd.  AutoSens Europe Website Book Pass Tutorial by Norman Koren Tuesday 8th October – 14:00 CEST – Room 6 Information Metrics for Performance and Optimization of Machine Vision Systems See also Image Information Metrics. Visit Imatest’s Booth #334 for Demonstrations Leader SFR-Fit MTF Measurement Software SFR-Fit is camera resolution measurement software that measures MTF (Modulation […]

Published January 30 2015, updated July 26 2024 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 […]

Standards: ISO 8600-1 2015: Part 1 — General requirements ISO 8600-2 2015: Part 2 — Particular requirements for rigid bronchoscopes ISO 8600-3 2019: Part 3 — Determination of field of view and direction of view of endoscopes with optics ISO 8600-4 2015: Part 4 — Determination of maximum width of insertion portion ISO 8600-5 2020: Part 5 — Determination of optical resolution of rigid endoscopes with optics ISO 8600-6 2020: Part 6 — Vocabulary ISO 8600-7 2012: Part 7 — Basic requirements for medical endoscopes of water-resistant type ISO 8600-8:2021: Endoscopes — Part 8: Particular requirements for capsule endoscopes Technical […]