# Logarithmic wedges: an improved design

We introduce the logarithmic wedge pattern, which has several significant advantages over the widely-used hyperbolic wedges found in ISO 12233 charts (current and older versions), eSFR ISO charts, and others. Logarithmic wedges will be supported in eSFR ISO charts starting with Imatest 2022.1.

The key advantage of the logarithmic wedges is that frequency decades or octaves occupy the same amount of space, as they do in most frequency response curves, for example in Bode plots. This enables them to accommodate a wider range of image resolutions than Hyperbolic wedges, which are linear in frequency (where $$frequency = n_{bars}/(pattern\ width)$$, which can result in the highest frequencies occupying a large portion of the real estate.

# Using images of noise to estimate image processing behavior for image quality evaluation

In the 2021 Electronic Imaging conference (held virtually) we presented a paper that introduced the concept of the noise image, based on the understanding that since noise varies over the image surface, noise itself forms an image, and hence can be measured anywhere, not just in flat patches.

You can download the full paper (in the original PDF format) here.

# Introducing MTS-RM-NIR

The Imatest Modular Test Stand Reflective Module now integrates with Metaphase NIR lights to allow fast, efficient testing in NIR wavelengths.

# Real-time focusing with Imatest Master direct data acquisition

Speed up your testing with real-time focusing in Imatest Master 2020.2.

Recent speed improvements allow for real-time focusing and allow users to analyze images from two types of sources:

Although the majority of images traditionally analyzed by Imatest have been from files (JPG, PNG, etc.), three modules, which can perform a majority of Imatest’s analyses, support direct data acquisition, and can be used for realtime analysis.

# Image Quality Testing for Webcams

Webcams are an increasingly vital tool for working remotely and staying connected with friends and loved ones. As such, webcam sales have experienced significant growth. We all know good and bad quality images when we see them, but quantifying a camera’s performance is critical for making design choices, sourcing components, and performing quality control. Developing these devices presents challenges common to the development of consumer cameras. (more…)

# Correcting Misleading Image Quality Measurements

We discuss several common image quality measurements that are often misinterpreted, so that bad images are falsely interpreted as good, and we describe how to obtain valid measurements.

# Describing and Sampling the LED Flicker Signal

High-frequency flickering light sources such as pulse-width modulated LEDs can cause image sensors to record incorrect levels. We describe a model with a loose set of assumptions (encompassing multi-exposure HDR schemes) which can be used to define the Flicker Signal, a continuous function of time based on the phase relationship between the light source and exposure window. (more…)

# Validation Methods for Geometric Camera Calibration

Camera-based advanced driver-assistance systems (ADAS) require the mapping from image coordinates into world coordinates to be known. The process of computing that mapping is geometric calibration. This paper provides a series of tests that may be used to assess the goodness of the geometric calibration

# Measuring camera Shannon information capacity with a Siemens star image

Shannon information capacity, which can be expressed as bits per pixel or megabits per image, is an excellent figure of merit for predicting camera performance for a variety of machine vision applications, including medical and automotive imaging systems.

# Verification of Long-Range MTF Testing Through Intermediary Optics

Measuring the MTF of an imaging system at its operational working distance is useful for understanding the system’s use case performance. (more…)

# Imatest EI Presentations Now Online

The research papers presented at this year’s Electronic Imaging Symposium (EI 2020) by Imatest engineers are now available. (more…)

# Making Dynamic Range Measurements Robust Against Flare Light

### Introduction

A camera’s Dynamic Range (DR) is the range of tones in a scene that can be reproduced with adequate contrast and good signal-to-noise ratio (SNR). Camera DR is often limited by flare light, which is stray light in the image, primarily caused by reflections between lens elements. Flare light reduces DR by fogging images; i.e., washing out detail in dark areas. (more…)

# Imatest and Furonteer Reduce Camera Intrinsic Calibration Time with Automated Machines

BOULDER, CO – JUNE 25TH, 2019 — Imatest, a global image quality testing solution provider, partnered with Furonteer, an automation equipment manufacturer, in early 2019 to provide production machines for geometric calibration of single and multicamera devices. (more…)

# P2020 Automotive Engineering Technology May 2019

Imatest attended the P2020 meeting on May 13 and 14, 2019 in Ann Arbor, Michigan. Paul Romancyzk, PhD., Senior Imaging Scientist, and Rob Sumner, Lead Engineer, represented Imatest. Paul co-led the discussion on Color Separation within the Image Quality for Machine Vision subgroup.

# Understanding collimator MTF loss using bronze and golden sample testing

by Henry Koren, inspired by Paul Romanczyk, edited by Norman Koren

Not all MTF measurement systems will necessarily provide the same results. The quality of the test target can impact the measurements you obtain. Long distance tests are ideally performed at the hyperfocal distance, where there is enough depth of field to have acceptable focus at infinity. (more…)

# Imatest at IEEE P2020

Imatest sent two engineers to the IEEE P2020 Automotive Imaging Quality face-to-face meeting in Dusseldorf, Germany this past February in 2019. The IEEE P2020 standard, which is still in development, aims to define KPIs and test procedures to address the many challenges relevant (and often unique) to automotive imaging. (more…)

# Reducing the cross-lab variation of image quality metrics

### Abstract

As imaging test labs seek to obtain objective performance scores of camera systems, many factors can skew the results. (more…)

# Considerations when evaluating a Near Infrared camera

Recent growth in the automotive and security industries has increased the number of cameras designed for viewing both Near Infrared (NIR) and visible wavelengths of light. NIR illumination is invisible to the human eye and can light a dark scene without being visible or annoying. (more…)