# LensDistortionData A description of estimated lens distortion that can be used to rectify images. ``` struct LensDistortionData ``` ## Overview See also: `AVCameraCalibrationData` Example of a per-pixel undistort function using this data: ``` func undistortPoint(lensDistortionData: LensDistortionData, imageSize: SIMD2, point: SIMD2) -> SIMD2 { // The lookup table holds the relative radial magnification for n linearly spaced radii. // The first position corresponds to radius = 0 // The last position corresponds to the largest radius found in the image. // Determine the maximum radius. let opticalCenter: SIMD2 = lensDistortionData.center let deltaXMax: Float = max(opticalCenter.x, imageSize.x - opticalCenter.x) let deltaYMax: Float = max(opticalCenter.y, imageSize.y - opticalCenter.y) let radiusMax: Float = sqrt(deltaXMax * deltaXMax + deltaYMax * deltaYMax) // Determine the vector from the optical center to the given point. let centerToPoint: SIMD2 = point - opticalCenter // Determine the radius of the given point. let pointRadius: Float = length(centerToPoint) // Look up the relative radial magnification to apply in the provided lookup table var magnification: Float = 1.0 let radialLut = lensDistortionData.radialLookupTable if pointRadius < radiusMax { // Linear interpolation based on piecewise linear function of normalized radius let value = pointRadius * Float(radialLut.count - 1) / radiusMax let index = Int(value) let fraction = value - Float(index) let magLeft = radialLut[index] let magRight = radialLut[index + 1] magnification = ( 1.0 - fraction ) * magLeft + fraction * magRight } else { magnification = radialLut[radialLut.count - 1] } // Apply radial magnification let centerToRectifiedPoint: SIMD2 = centerToPoint + magnification * centerToPoint // Construct output return opticalCenter + centerToRectifiedPoint } ``` ## Topics ### Initializers [`init(center: SIMD2, radialLookupTable: [Float])`](/documentation/RealityKit/LensDistortionData/init(center:radialLookupTable:)) Initializes a new immutable data structure describing lens distortion estimation. ### Instance Properties [`let center: SIMD2`](/documentation/RealityKit/LensDistortionData/center) The center pixel of the radial distortion mapping. [`let radialLookupTable: [Float]`](/documentation/RealityKit/LensDistortionData/radialLookupTable) A linear interpolation lookup table from the `center` to the maximum distance corner of the image. This describes the magnification of radius at a given radius. This is the same structure as `lensDistortionLookupTable` in `AVCameraCalibrationData` and can be used in a similar manner, with the data already converted into a float array. ## Relationships ### Conforms To [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`Sendable`](/documentation/Swift/Sendable) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)