The SFRplus test chart can be used with the SFRplus module in Imatest 3.2 or later to measure MTF, lateral chromatic aberration, distortion, and tonal response. The SFRplus module features fully automated region-of-interest detection. The SFRplus chart offers significant advantages over commonly used charts such as the ISO 12233 chart, including 1) much less wasted area, 2) the ability to produce a map of sharpness over the sensor surface, 3) better measurement accuracy due to the lower contrast, and 4) full support for automated testing.

Ideal for evaluation response of digital systems to the slanted sharp edge function and used for MTF analysis. 

For measurement of sharpness, the main driver of variation is noise. A powerful noise reduction technique called modified apodization is available for slanted-edge measurements (SFR, SFRplus, eSFR ISO and SFRreg). This technique makes virtually no difference in low-noise images, but it can significantly improve measurement accuracy for noisy images, especially at high spatial frequencies (f > Nyquist/2). It is applied when the MTF noise reduction (modified apodization) checkbox is checked in the SFR input dialog box or the SFRplus or eSFR ISO More settings window.

New infrared test charts and analysis software modernize testing of infrared cameras Once viewed as exotic devices, infrared camera systems have moved into the mainstream in many industries, particularly in security and defense. From night-vision helmets, scopes, and security cameras to ballistic missile tracking telescopes, IR cameras have become as commonplace as they are mission-critical. As with other advanced technologies, quality control is key to successful development and application of IR camera systems, with the quality of the image itself being paramount to most organizations.

Now Available – Infrared Test Charts Imatest’s new Infrared SFRplus test charts support testing of visible light through Medium Wavelength Infrared (MWIR). The large charts have a sturdy aluminum substrate and are suitable for outdoor field testing, as well as lab testing. Details here.

Version 3.4.1 of Imatest Master, IT, and IS is now available and includes optimizations to SFR and SFRPlus that drastically reduce processing time for computing MTF (sharpness). Depending on options and settings, results are delivered in half the time or better. Download the latest version today: www.imatest.com/download

Imatest versions Imatest Studio, with everything individual photographers need to test their cameras, lenses, and printers. Imatest Master, the full-featured industrial-strength version for professionals and imaging system developers. Comparision between versions SFR Studio Master Edge and MTF (SFR) plot Chromatic aberration plot Batch runs (multiple input files)   SFR Any Angle: Calculate MTF for any edge angle.   Display edge and MTF for R, B, and B channels, in addition to Y (luminance) channel   Colorcheck Studio Master Tonal response and noise analyses for B&W patches La*b* color error and Color analysis Batch runs (multiple input files)   User-supplied reference […]

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Sharpness Noise Dynamic-Range Color-Accuracy Distortion Uniformity Chromatic Aberration Veiling Glare Color Moire Artifacts Compression Print Dmax Print Color Gamut Links Image quality is one of those concepts that is greater than the sum of its parts. But you can’t ignore the parts if your goal is to produce images of the highest quality. Every image quality factor counts. This page introduces the key image quality factors, describes how Imatest™ measures them, and explains what, if anything, can be done to improve them. It is a guide to Imatest organized by image quality factor. Additional information can be found under Tour […]

Sharpness is arguably the most important single image quality factor: it determines the amount of detail an image can convey. The image on the upper right illustrates the effects of reduced sharpness (from running Image Processing with one of the Gaussian filters set to 0.7 sigma). Device or system sharpness is measured as a Spatial Frequency Response (SFR), also called Modulation Transfer Function (MTF). MTF is the contrast at a given spatial frequency (measured in cycles or line pairs per distance) relative to low frequencies. The 50% MTF frequency correlates well with perceived sharpness— much better than the old vanishing […]