In order to calculate FoV in units of distance (cm) a chart geometrical distance has to be entered into the Rescharts More settings window.
Countour plot vs parametir cplot iso#
Both results are included in CSV and JSON results (for all modules that calculate distortion).įield of view (FoV) is calculated for SFRplus, Checkerboard, and eSFR ISO by applying the distortion model equation to the top, side, and diagonal (always r = 1) of the image.
Countour plot vs parametir cplot tv#
The selection affects only graphic displays (ISO TV distortion = SMIA TV distortion ⁄ 2). You can make the selection on the left side of the Options II window (button on the lower-right of the Imatestmain window). Imatest 5.1+ allows you to select between traditional TV distortion (now a part of several ISO standards, including ISO 16505) and SMIA TV distortion. In the SMIA definition, both A and B are bottom-to-top distances. In the traditional definition, TV distortion is the change (Δ) of the center-to-top distance divided by by the bottom-to-top distance. The same definition appears in “Measurement and analysis of the performance of film and television camera lenses” published by the European Broadcasting Union (EBU).Īt Imatest we have traditionally used the SMIA definition, which has been widely adopted in the mobile imaging industry, because it is self-consistent. The traditional definition, shown on the right, has been adapted from the publication “Optical Terms,” published by Fujinon. SMIA TV distortion is twice as large (2X) as traditional TV distortion, now included in several standards. Instead it is calculated from the distortion coefficients using the selected equation, and using virtual horizontal lines located 1% of the image height below the top and above the bottom of the image.
\(r_u = \arctan(10 p_1 r_d )/(10 p_1 ) \ \ p_1 0 is pincushion < 0 is barrel.Īlgorithm: SMIA TV Distortion is not actually calculated from the upper and lower bars, whose locations can vary considerably in different images. r is normalized to the center-to-corner distance. In the equations which apply to several modules, r d is the distorted (measured) radius normalized to the center-to-corner distance.
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