Distortion Curve

The Distortion curve describes an angular relationship between the incoming ray's angle and the imager ray's angle. This relationship is described in an *.OPTDistortion file that is interpreted by Speos to render the camera behavior.

Distortion Curve Principle

Speos algorithm is based on the pinhole camera principle.

In a pinhole camera model, the size of the image is predicted by the distance between the chief ray (ray starting from the object point passing through the center of the aperture stop) and the optical axis in the imager plane.

Knowing the relationship between incoming ray’s angle and the imager ray’s angle for each object point allows Speos to simulate the camera behavior. This angular relationship is called Distortion Curve. The Distortion Curve, basically, provides the output ray direction in relation to the input ray direction.

Note: This curve is also called the "Chief ray angle curve" or "Principal ray angle curve".

Distortion Curve File

The distortion curve (.OPTDistortion) file describes the object to image angular relationship and allows Speos to render the camera behavior.

Tip: The information needed to fill this file are usually provided by the supplier. You only need to format it.

Note: Simulation results generated with distortion curve file V2.0 (.xmp, .png, .hdr) are not rotated. Simulation results generated with distortion curve file V1.0 (.xmp, .png, .hdr) are rotated.


Line	Description	Example		Comments
1	Header	OPTIS - Optical distortion file v1.0		Version (v1.0) could be used for further file format update.
2	Comment	Created by x user with DistortionCurveGenerator, 02/12/2011 13:18:32		Users/suppliers comments. For information purposes, without any impact on simulation results.
3	Format	0		0 indicates that the distortion curve is given as a list of sample of object angle vs image angle. No other value will be supported in V1.0 version.
4	Number of samples	91
5	Object Angle vs. Image Angle	0 0.017453278 0.034906556 0.052359333 0.069813111 0.087266389 0.104719667 0.122172944 ... ... 0.261799167 0.279252444 0.296705722	0 0.0273028387171337 0.0537954641261183 0.0795296582853432 0.1045521483695 0.128905211037813 0.152627193841727 0.175752965965063 ... ... 0.342599269505361 0.361513076284991 0.3800535557331	Angle values in radian.