/* * Copyright 2007 ZXing authors * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /*namespace com.google.zxing.common {*/ /** *
This class implements a perspective transform in two dimensions. Given four source and four * destination points, it will compute the transformation implied between them. The code is based * directly upon section 3.4.2 of George Wolberg's "Digital Image Warping"; see pages 54-56.
* * @author Sean Owen */ export default class PerspectiveTransform { constructor(a11 /*float*/, a21 /*float*/, a31 /*float*/, a12 /*float*/, a22 /*float*/, a32 /*float*/, a13 /*float*/, a23 /*float*/, a33 /*float*/) { this.a11 = a11; this.a21 = a21; this.a31 = a31; this.a12 = a12; this.a22 = a22; this.a32 = a32; this.a13 = a13; this.a23 = a23; this.a33 = a33; } static quadrilateralToQuadrilateral(x0 /*float*/, y0 /*float*/, x1 /*float*/, y1 /*float*/, x2 /*float*/, y2 /*float*/, x3 /*float*/, y3 /*float*/, x0p /*float*/, y0p /*float*/, x1p /*float*/, y1p /*float*/, x2p /*float*/, y2p /*float*/, x3p /*float*/, y3p /*float*/) { const qToS = PerspectiveTransform.quadrilateralToSquare(x0, y0, x1, y1, x2, y2, x3, y3); const sToQ = PerspectiveTransform.squareToQuadrilateral(x0p, y0p, x1p, y1p, x2p, y2p, x3p, y3p); return sToQ.times(qToS); } transformPoints(points) { const max = points.length; const a11 = this.a11; const a12 = this.a12; const a13 = this.a13; const a21 = this.a21; const a22 = this.a22; const a23 = this.a23; const a31 = this.a31; const a32 = this.a32; const a33 = this.a33; for (let i = 0; i < max; i += 2) { const x = points[i]; const y = points[i + 1]; const denominator = a13 * x + a23 * y + a33; points[i] = (a11 * x + a21 * y + a31) / denominator; points[i + 1] = (a12 * x + a22 * y + a32) / denominator; } } transformPointsWithValues(xValues, yValues) { const a11 = this.a11; const a12 = this.a12; const a13 = this.a13; const a21 = this.a21; const a22 = this.a22; const a23 = this.a23; const a31 = this.a31; const a32 = this.a32; const a33 = this.a33; const n = xValues.length; for (let i = 0; i < n; i++) { const x = xValues[i]; const y = yValues[i]; const denominator = a13 * x + a23 * y + a33; xValues[i] = (a11 * x + a21 * y + a31) / denominator; yValues[i] = (a12 * x + a22 * y + a32) / denominator; } } static squareToQuadrilateral(x0 /*float*/, y0 /*float*/, x1 /*float*/, y1 /*float*/, x2 /*float*/, y2 /*float*/, x3 /*float*/, y3 /*float*/) { const dx3 = x0 - x1 + x2 - x3; const dy3 = y0 - y1 + y2 - y3; if (dx3 === 0.0 && dy3 === 0.0) { // Affine return new PerspectiveTransform(x1 - x0, x2 - x1, x0, y1 - y0, y2 - y1, y0, 0.0, 0.0, 1.0); } else { const dx1 = x1 - x2; const dx2 = x3 - x2; const dy1 = y1 - y2; const dy2 = y3 - y2; const denominator = dx1 * dy2 - dx2 * dy1; const a13 = (dx3 * dy2 - dx2 * dy3) / denominator; const a23 = (dx1 * dy3 - dx3 * dy1) / denominator; return new PerspectiveTransform(x1 - x0 + a13 * x1, x3 - x0 + a23 * x3, x0, y1 - y0 + a13 * y1, y3 - y0 + a23 * y3, y0, a13, a23, 1.0); } } static quadrilateralToSquare(x0 /*float*/, y0 /*float*/, x1 /*float*/, y1 /*float*/, x2 /*float*/, y2 /*float*/, x3 /*float*/, y3 /*float*/) { // Here, the adjoint serves as the inverse: return PerspectiveTransform.squareToQuadrilateral(x0, y0, x1, y1, x2, y2, x3, y3).buildAdjoint(); } buildAdjoint() { // Adjoint is the transpose of the cofactor matrix: return new PerspectiveTransform(this.a22 * this.a33 - this.a23 * this.a32, this.a23 * this.a31 - this.a21 * this.a33, this.a21 * this.a32 - this.a22 * this.a31, this.a13 * this.a32 - this.a12 * this.a33, this.a11 * this.a33 - this.a13 * this.a31, this.a12 * this.a31 - this.a11 * this.a32, this.a12 * this.a23 - this.a13 * this.a22, this.a13 * this.a21 - this.a11 * this.a23, this.a11 * this.a22 - this.a12 * this.a21); } times(other) { return new PerspectiveTransform(this.a11 * other.a11 + this.a21 * other.a12 + this.a31 * other.a13, this.a11 * other.a21 + this.a21 * other.a22 + this.a31 * other.a23, this.a11 * other.a31 + this.a21 * other.a32 + this.a31 * other.a33, this.a12 * other.a11 + this.a22 * other.a12 + this.a32 * other.a13, this.a12 * other.a21 + this.a22 * other.a22 + this.a32 * other.a23, this.a12 * other.a31 + this.a22 * other.a32 + this.a32 * other.a33, this.a13 * other.a11 + this.a23 * other.a12 + this.a33 * other.a13, this.a13 * other.a21 + this.a23 * other.a22 + this.a33 * other.a23, this.a13 * other.a31 + this.a23 * other.a32 + this.a33 * other.a33); } }