Imatest InfoDR (Information-based Dynamic Range) refers to the Imatest module and test charts designed to measure C4 information capacity over a wide range of illumination — especially for low light. This page, Using InfoDR, Part 2 — describes how to analyze the InfoDR charts in Imatest Rescharts and Color/Tone. Part 1 – Introduction – C4 Information Capacity – InfoDR chart versions – Lighting – Measuring illumination Photograph (framing)  Part 2 – Open, Select, & Read – Setup window – Results – Information-related displays Comparison with traditional DR – More settings – Auto mode – Color/Tone  Related pages Using InfoDR, Part 1 — describes the InfoDR charts and how to […]

Imatest InfoDR (Information-based Dynamic Range) refers to an Imatest module and a set of test charts designed to measure C4 information capacity over a wide range of illumination — especially for low light. This page, Part 1, describes the InfoDR charts and how to photograph them. Part 1 – Introduction – C4 Information Capacity – InfoDR chart versions – Lighting – Measuring illumination Photograph (framing) – Appendix: InfoDR chart design  Part 2 – Open, Select, & Read – Setup window – Results – Information-related displays – More settings  Related pages Using InfoDR, Part 1 — describes the InfoDR charts and how to photograph them. Using InfoDR, Part 2 — describes how to analyze the […]

Create test chart files for high quality inkjet prints or screen display News — Imatest 25.1 (pilot program):  m x n grayscale or color charts can now be created using selectable density steps or reference files (identical to those used in Color/Tone). Imatest 24.2:  Test charts can now create high quality screen displays.         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 […]

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 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 […]

From the Imatest main window, click on SFR or Rescharts on the upper left. SFR allows you to analyze multiple regions and to run batches of files. Rescharts (1. Slanted-edge SFR) allows you to analyze single regions in a highly-interactive interface. ISO 12233:2000 chart images, which have contrasty (≥40:1) slanted-edges, can be downloaded from dpreview.com reviews, typically in the last page titled “Compared to…,” and from Imaging-resource.com reviews, typically on the page labeled “sample images.” We no longer recommend such high contrast images, because saturation can lead to inaccurate results. 4:1 or 10:1 contrast images are much preferred. Image file […]

Running Rescharts slanted-edge modules (Interactive and Auto mode settings) Imatest Rescharts slanted edge modules— SFRplus, eSFR ISO, SFRreg, and Checkerboard— perform highly automated measurements of several key image quality factors using specially-designed test charts. This document shows how to run these modules in Rescharts and how to save settings for automated runs.  Four introductory pages —  SFRplus, eSFR ISO, SFRreg, and Checkerboard — describe each module and explain how to obtain and photograph the chart.  Rescharts Results Part 3 and Part 4 illustrate the results. Selecting files – Setup window – ROI selection & analysis – Edge ID files – Speeding up runs […]

Interactive measurement of vignetting and sensor nonuniformity Flatfield-Interactive measures image nonuniformity, which can be caused by the lens, the sensor, and the lighting— the same parameters measured by Flatfield— in an interactive interface that can be updated in near-realtime. It can also  photo response nonuniformity (PRNU) derived from the EMVA 1288 standard, ISO 18844 flare (veiling glare), and more. Flatfield-Interactive can display pixel and color shading contour plots, pixel level histograms, hot and dead pixels, grid and grid contour plots, and much more. The table below contains a complete list of displays. Many of the features are also described in Using […]

Imatest eSFR ISO results Imatest eSFR ISO performs highly automated measurements of several key image quality factors using one of three versions of the ISO 12233:2017 Edge SFR chart: Standard, Enhanced, or Extended or the Extended ISO 12233:2023 . 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, measured from the grayscale patches surrounding the center of the chart, includes all types of noise calculated by Color/Tone Interactive and Color/Tone Auto (standard pixel noise, […]

Running eSFR ISO – Rescharts eSFR ISO – eSFR ISO setup window – Speeding up – More Settings window – Secondary Readouts – Gamma – Auto mode settings – Warnings – eSFR ISO summary Running eSFR ISO Imatest eSFR ISO performs highly automated measurements of several key image quality factors using one of three versions of the ISO 12233:2017 Edge SFR chart: Standard, Enhanced, or Extended or the Extended ISO 12233:2023 Edge SFR chart. This document shows how to run eSFR ISO in Rescharts and how to save settings for automated runs. Part 1 introduced eSFR ISO and explained how […]

Direct image acquisition allows images to be captured directly from a variety of devices without first being stored as files. It has several important applications. Introduction – Direct data reload for realtime analysis – Signal averaging By continuously reloading images, it can be used for realtime (or near-realtime) image analysis, where “realtime” means that analysis appears to be instant in the timeframe of human perception. It is especially valuable for focusing with slanted-edges (which can be analyzed faster than other MTF patterns) or with cropped areas of arbitrary images.   It is very useful for signal averaging — a technique […]

Analyze images of the Calibrite (X-Rite) Colorchecker Note:  Colorcheck is a legacy module, no longer recommended for new work. Use Color/Tone Interactive or Auto instead. Introduction – Photographing the chart – Running Colorcheck – Settings – Output Fig. 1. Grayscale tonal response & noise – Fig. 2. Noise detail – Fig. 3. a*b* color error  Saturation-corrected – FIg. 4. Color analysis – Fig. 5. Temporal noise – Saving results    Related:  Color/Tone Interactive — Color/Tone Auto — Colorcheck/Color/Tone Appendix —  Color/Tone/eSFR ISO Noise Wikipedia: Color difference    Introduction Colorcheck analyzes images of the well-known Calibrite (formerly X-RiteTM) ColorChecker®* (available from the Imatest Store) […]

Selecting files – Setup window – ROI selection & analysis area – Edge ID Files More settings window – Secondary Readout  – Settings area – Auto mode window Warnings – Clipping – Summary    Using Checkerboard Part 1 – Checkerboard patterns and how to photograph them Running Checkerboard (Interactive and Auto mode settings) Imatest Checkerboard performs highly automated measurements of sharpness (expressed as Spatial Frequency Response (SFR), also known as Modulation Transfer Function (MTF)), Lateral Chromatic Aberration , and optical distortion from tilted checkerboard images.The primary advantage of Checkerboard is that the field of view, i.e., the framing, does not need to be tied to the chart size (as it […]

The Pass/Fail monitor (introduced In Imatest 4.0) provides a real-time indication of whether a device has passed or failed a test. It saves the trouble of digging through results— in figures or CSV or JSON files. Key features: It can stay open while modules run, displaying results immediately after calculations are complete. It works best on systems with a high resolution screen or dual screens. It interfaces with most Imatest analysis modules. It can be extremely valuable for developing and testing Pass/Fail criteria for Imatest IT (Industrial Testing). It can call several utilities for helping with this process. It displays […]

Test Charts creates test chart files for printing on high quality inkjet printers. This page focuses on Scalable Vector Graphics (SVG) charts, many of which are used for measuring sharpness (MTF) with Imatest SFR, SFRplus, eSFR ISO, Checkerboard, and SFRreg. (Bitmap charts are described elsewhere.) SVG charts can be printed any size at a printer’s maximum quality (i.e., resolution) with no limitations, and they generally require much less storage than bitmap images. The SVG charts designed for automated testing with SFRplus and eSFR ISO (based on ISO 12233:2014/2017) have numerous advantages over the familiar but obsolete ISO 12233:2000 chart. Most […]

Instructions and reference Related web pages Simatest:  Overview – Compact introduction to Simatest. Recommended for getting started. Simatest examples – Examples of how Simatest can be used. Compares simulations to measurement. Much more readable than this long page. Image Sensor Noise – measurement and modeling – using raw files for image sensor Dynamic Range and Simatest Using Color/Tone Interactive – Interactive analysis of color & grayscale test charts Color/Tone & eSFR ISO noise measurements – describes how to measure image sensor noise from raw images Dynamic Range – a general introduction with links to Imatest modules that calculate it Noise in Photographic Images – […]

Photographic scientists and engineers stress the fact that no single number satisfactorily describes the ability of a photographic system to reproduce the small-scale attributes of the subject —Leslie Stroebel,John Compton, Ira Current, Richard Zakia Basic Photographic Materials and Processes, Second edition, p. 273 (Micro-image evaluation chapter), Focal Press, 2000 News: Imatest 23.1 contains a new method for calculating the information capacity from slanted-edge patterns, which has been developed and presented in the white paper,  “Measuring Camera Information Capacity with Imatest“. The slanted-edge method is faster and more efficient than the Siemens star method, but not as good for measuring artifacts […]

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 Information capacity Other results, not derived from slanted-edges are covered in Part […]

Introduction – Using raw files – Bayer raw and RCCC files – LibRaw demosaicing (for commercial raw files)  Differences with in-camera JPEGs – Monochrome images – Bayer frequency units  DNG files – Rawview utility – Generalized Read Raw (for binary raw files)  Decompanding – Estimating image width & height – 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 […]