Imatest’s charts and software allow you, our users, to measure the characteristics and parameters of your imaging system. Quite often these measurements are used simply as metrics of image quality, to indicate the limits of the performance you can expect from your system or to predict the quality of the images it can take.
Some of the results Imatest can give you, however, are immediately actionable. Some results we supply can be used to directly improve the test image –and subsequent ones taken by the same system in the wild, of course– by correcting the error which was measured. No new components need to be purchased, no judgement calls need to be made- sometimes the solution to a problem can be found with a mathematical model and a little computation. Once you measure such parameters with Imatest you can correct for them, thereby minimizing (or completely removing) their effect. This is an aspect of tuning the image processing pipeline, which is usually done by a dedicated Image Signal Processing (ISP) chip in a device to transform raw sensor data into an appropriate image.
At Imatest, we informally call this “closing the loop”, because it completes the cycle from the camera-under-test to measurement and back to the camera (in the form of some adjustment).
Today, we’re going to illustrate how to take radial distortion measurements from Imatest and use them to correct the distortion out of images taken with that camera (without buying a new lens). (more…)