How is Imatest pronounced? How do I get started? Which version should I buy? How do I purchase Imatest? I purchased Imatest but didn’t receive the confirmation email with the password. What should I do? Is there a CD version? Will I receive anything in the mail? How do I install Imatest on a computer that isn’t connected to the Internet? What test charts do I need? Are they included with Imatest? What is Matlab? Do I need it to run Imatest? How often is Imatest updated? I purchased Imatest several months ago. How do I get the latest […]

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 […]