$a11
$a11
<p>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.</p>
quadrilateralToQuadrilateral(mixed $x0, mixed $y0, mixed $x1, mixed $y1, mixed $x2, mixed $y2, mixed $x3, mixed $y3, mixed $x0p, mixed $y0p, mixed $x1p, mixed $y1p, mixed $x2p, mixed $y2p, mixed $x3p, mixed $y3p) : mixed
| mixed | $x0 | |
| mixed | $y0 | |
| mixed | $x1 | |
| mixed | $y1 | |
| mixed | $x2 | |
| mixed | $y2 | |
| mixed | $x3 | |
| mixed | $y3 | |
| mixed | $x0p | |
| mixed | $y0p | |
| mixed | $x1p | |
| mixed | $y1p | |
| mixed | $x2p | |
| mixed | $y2p | |
| mixed | $x3p | |
| mixed | $y3p |
<?php
/*
* 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 Zxing\Common;
/**
* <p>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.</p>
*
* @author Sean Owen
*/
final class PerspectiveTransform
{
private $a11;
private $a12;
private $a13;
private $a21;
private $a22;
private $a23;
private $a31;
private $a32;
private $a33;
private function __construct(
$a11, $a21, $a31,
$a12, $a22, $a32,
$a13, $a23, $a33
) {
$this->a11 = $a11;
$this->a12 = $a12;
$this->a13 = $a13;
$this->a21 = $a21;
$this->a22 = $a22;
$this->a23 = $a23;
$this->a31 = $a31;
$this->a32 = $a32;
$this->a33 = $a33;
}
public static function quadrilateralToQuadrilateral(
$x0, $y0,
$x1, $y1,
$x2, $y2,
$x3, $y3,
$x0p, $y0p,
$x1p, $y1p,
$x2p, $y2p,
$x3p, $y3p
) {
$qToS = self::quadrilateralToSquare($x0, $y0, $x1, $y1, $x2, $y2, $x3, $y3);
$sToQ = self::squareToQuadrilateral($x0p, $y0p, $x1p, $y1p, $x2p, $y2p, $x3p, $y3p);
return $sToQ->times($qToS);
}
public static function quadrilateralToSquare(
$x0, $y0,
$x1, $y1,
$x2, $y2,
$x3, $y3
) {
// Here, the adjoint serves as the inverse:
return self::squareToQuadrilateral($x0, $y0, $x1, $y1, $x2, $y2, $x3, $y3)->buildAdjoint();
}
public function buildAdjoint()
{
// Adjoint is the transpose of the cofactor matrix:
return new PerspectiveTransform($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);
}
public static function squareToQuadrilateral(
$x0, $y0,
$x1, $y1,
$x2, $y2,
$x3, $y3
) {
$dx3 = $x0 - $x1 + $x2 - $x3;
$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 {
$dx1 = $x1 - $x2;
$dx2 = $x3 - $x2;
$dy1 = $y1 - $y2;
$dy2 = $y3 - $y2;
$denominator = $dx1 * $dy2 - $dx2 * $dy1;
$a13 = ($dx3 * $dy2 - $dx2 * $dy3) / $denominator;
$a23 = ($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, $a23, 1.0);
}
}
public function times($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 * $other->a33);
}
public function transformPoints(&$points, &$yValues = 0)
{
if ($yValues) {
$this->transformPoints_($points, $yValues);
return;
}
$max = count($points);
$a11 = $this->a11;
$a12 = $this->a12;
$a13 = $this->a13;
$a21 = $this->a21;
$a22 = $this->a22;
$a23 = $this->a23;
$a31 = $this->a31;
$a32 = $this->a32;
$a33 = $this->a33;
for ($i = 0; $i < $max; $i += 2) {
$x = $points[$i];
$y = $points[$i + 1];
$denominator = $a13 * $x + $a23 * $y + $a33;
$points[$i] = ($a11 * $x + $a21 * $y + $a31) / $denominator;
$points[$i + 1] = ($a12 * $x + $a22 * $y + $a32) / $denominator;
}
}
public function transformPoints_(&$xValues, &$yValues)
{
$n = count($xValues);
for ($i = 0; $i < $n; $i++) {
$x = $xValues[$i];
$y = $yValues[$i];
$denominator = $this->a13 * $x + $this->a23 * $y + $this->a33;
$xValues[$i] = ($this->a11 * $x + $this->a21 * $y + $this->a31) / $denominator;
$yValues[$i] = ($this->a12 * $x + $this->a22 * $y + $this->a32) / $denominator;
}
}
}