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