PerspectiveTransformEngine class

Production-grade perspective transform engine implementing 4-point homography via Direct Linear Transform (DLT) with bilinear interpolation.

Inspired by OpenCV's cv::getPerspectiveTransform() + cv::warpPerspective() and Scanbot SDK's document perspective correction pipeline.

This engine:

  1. Computes the 3×3 homography matrix from 4 source → 4 destination point pairs
  2. Applies inverse mapping with bilinear interpolation for artifact-free warping
  3. Provides utility methods for coordinate mapping and ROI extraction

Properties

hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Static Methods

computeDocumentHomography(DocumentCorners corners, {required int outputWidth, required int outputHeight}) → Float64List
Computes the homography to warp a detected document quadrilateral to a flat rectangle of specified dimensions.
computeHomography(List<Offset> src, List<Offset> dst) → Float64List
Computes a 3×3 homography matrix mapping 4 source points to 4 destination points using the Direct Linear Transform (DLT) algorithm.
homographyToMatrix4(Float64List h) → Matrix4
Converts a Float64List homography to a Flutter Matrix4 for use in CustomPainter transforms and widget rendering.
transformPoint(Float64List homography, Offset point) → Offset
Maps a single point through the homography transformation.
warpDocument(Uint8List gray, int srcWidth, int srcHeight, DocumentCorners corners, {int? outputWidth, int? outputHeight}) → PerspectiveWarpResult
Warps a document image from detected quad corners to a flat rectangle.
warpPerspective(Uint8List gray, int srcWidth, int srcHeight, Float64List homography, int dstWidth, int dstHeight, {int backgroundColor = 255}) → Uint8List
Warps a grayscale image using the given homography matrix with bilinear interpolation for sub-pixel accuracy.