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   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   Perceptual metrics   Module operation and misc.   [api] section   […]

Analyses & Output – INI settings – Chart Definition Files – Chart Definition Utility   Data outputs from the Arbitrary Charts Module are different from other modules in Imatest: Only JSON files are output, not CSV or XML. The structure of JSON is substantially different than other modules.  If several images are run in a batch, results from all images may be contained in a single JSON. Since the Arbitrary Charts Module is based on the concept of a custom layout of features, there is no fixed structure to the measurement results that the Module produces. Instead, the module simply produces […]

Analyses & Output – INI settings – Chart Definition Files – Chart Definition Utility   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 are unsupported […]

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 […]

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 that […]

Imatest 4.5+   The Checkerboard Module is strongly recommended for distortion measurements because its corner detection algorithm is much more accurate and it is tolerant of large amounts of optical distortion, which can cause the Distortion module to fail. Checkerboard, which calculates distortion, MTF, and lateral chromatic aberration is Imatest’s primary recommended means of calculating optical distortion. The Distortion module will be removed after the 22.2 release and is not recommended for new work. If you are using it, we recommend avoiding the grid (line) pattern because it is much fussier than the checkerboard: thin lines may fail to be detected; thick lines reduce […]

Table of Contents Intro to stray light (flare) How to test for stray light Setting up for stray light testing Physical set up and alignment Test environment Test coverage: extent and sampling Image data Imatest’s hardware solution for stray light testing Imatest Motorized Gimbal Broadband Halogen Fiber Optic Illuminator (Benchtop Setup)  Imatest configurable light source Imatest Motorized Test Stand Imatest Blackout Curtain Fixture   Intro to Stray Light (Flare) What is stray light and how is it measured? Stray light, also known as flare, is any light that reaches the detector (i.e., the image sensor) other than through the designed […]

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 […]

Analysis of wedge patterns with the  Imatest Wedge and eSFR ISO modules News  2021.2 —  Logarithmic wedges: a superior design describes the advantages of logarithmic wedges, which have a much better distribution of spatial frequencies than hyperbolic wedges, allowing a larger maximum/minimum frequency ratio. Supported by Imatest (automatically detected) since 2021, but (as of May 2022) not currently included in standard eSFR ISO charts (though available on request).  2020.2 —  Calculations were greatly sped up in order to improve performance of direct image acquisition. During the testing of the speedup with direct acquisition, we found that Wedge results were unstable during […]

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 […]

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 […]

Photographing the chart – Running Stepchart – Settings – Output – Temporal noise Auto-exposure – Saving – Dynamic range (DR) – DR definitions – Algorithm   Stepchart measures the tonal response, noise, dynamic range, and ISO sensitivity of digital cameras and scanners using Reflective grayscale step charts such as the Kodak Q-13 and Q-14 Gray Scales, which have a single row of patches (a linear arrangement), or charts such as the ISO-14524 or ISO-15739 charts, with non-linear (multiple rows; may be circular) patch arrangements, shown below, or Transmissive (backlit) grayscale step charts such as the Imatest 36-patch Dynamic Range or 36-patch […]

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 […]

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 […]

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 with two light and two dark quadrants). Unlike standard test charts, these patterns do not need to be located on a flat (planar) surface. Since Region of Interest (ROI) detection is automatic, they may be positioned where needed. Depending on the image source, they offer several advantages. You can Test images at infinity distance (or any distance of choice) using a compact projection system such as a collimator […]

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 […]

Imatest SFRplus results Imatest SFRplus performs highly automated measurements of several key image quality factors using the specially-designed SFRplus test chart. Unlike most other modules, the user never has to manually select Regions of Interest (ROIs). Image quality factors include Sharpness, expressed as Spatial Frequency Response (SFR), also known as the Modulation Transfer Function (MTF), Noise, Lateral Chromatic Aberration, Distortion (with nearly as detailed output as the Distortion module). Described in detail here. Tonal response (again, with less detail than Stepchart; no noise statistics) Color accuracy, when used with an SFRplus that contains the optional color pattern, located above the […]

The SFRplus chart: description and how to photograph it Slanted-edge test – Advantages – Obtain chart – Framing – No bars – Lighting Distance – Exposure – Tips – Links Watch on YouTube. Download 1080p/720p/540p. Purchase SFRplus Test Charts from the Imatest Store. Imatest SFRplus performs highly automated measurements of several key image quality factors using a specially-designed test chart that may be purchased from the Imatest store (recommended) or printed on a high-quality inkjet printer. The user does not need to manually select Regions of Interest (ROIs). Image quality factors include Sharpness, expressed as Spatial Frequency Response (SFR), also known as Modulation Transfer Function (MTF), which can be mapped over the entire image, Noise (limited: […]