php method to implement color space conversion: first create a PHP sample file; then create "HSL, HSV, RGB color space"; finally implement it through "protected function tearDown(){...}" and other methods Convert.
The operating environment of this article: windows7 system, PHP7.1 version, DELL G3 computer
How does php achieve color space conversion?
PHP realizes RGB, HSL, HSV color space conversion
<?php
/**
* HSL色彩空间描述
* @author shizhuolin
*/
class HSL {
/**
* 色相 0-360
* @var float
*/
protected $_hue;
/**
* 饱和度 0-1
* @var float
*/
protected $_saturation;
/**
* 亮度 0-1
* @var float
*/
protected $_lightness;
/**
* 构造HSL色彩空间描述
* @param float $hue
* @param float $saturation
* @param float $lightness
*/
public function __construct($hue=0, $saturation=0, $lightness=0) {
$this->_hue = $hue;
$this->_saturation = $saturation;
$this->_lightness = $lightness;
}
/**
* 获取色相
* @return float
*/
public function getHue() {
return $this->_hue;
}
/**
* 获取饱和度
* @return float
*/
public function getSaturation() {
return $this->_saturation;
}
/**
* 获取亮度
* @return float
*/
public function getLightness() {
return $this->_lightness;
}
/**
* 获取RGB形式色彩空间描述
* @return RGB
*/
public function toRGB() {
$h = $this->getHue();
$s = $this->getSaturation();
$l = $this->getLightness();
if ($s == 0) {
require_once 'RGB.php';
return new RGB($l, $l, $l);
}
$q = $l < 0.5 ? $l * (1 + $s) : $l + $s - ($l * $s);
$p = 2 * $l - $q;
$hk = $h / 360;
$tR = $hk + (1 / 3);
$tG = $hk;
$tB = $hk - (1 / 3);
$tR = $this->getTC($tR);
$tG = $this->getTC($tG);
$tB = $this->getTC($tB);
$tR = $this->getColorC($tR, $p, $q);
$tG = $this->getColorC($tG, $p, $q);
$tB = $this->getColorC($tB, $p, $q);
require_once 'RGB.php';
return new RGB($tR, $tG, $tB);
}
private function getColorC($tc, $p, $q) {
if ($tc < (1 / 6)) {
return $p + (($q - $p) * 6 * $tc );
} else if ((1 / 6) <= $tc && $tc < 0.5) {
return $q;
} else if (0.5 <= $tc && $tc < (2 / 3)) {
return $p + (($q - $p) * 6 * (2 / 3 - $tc) );
} else {
return $p;
}
}
private function getTC($c) {
if ($c < 0)
$c++;
if ($c > 1)
$c--;
return $c;
}
/**
* 获取 array形式HSL色彩描述
* @return array
*/
public function toArray() {
return array(
'hue' => $this->getHue(),
'saturation' => $this->getSaturation(),
'lightness' => $this->getLightness()
);
}
}
<?php
/**
* HSV色彩空间描述
* @author shizhuolin
*/
class HSV {
/**
* 色相 0-260
* @var float
*/
protected $_hue;
/**
* 饱和度 0-1
* @var float
*/
protected $_saturation;
/**
* 色调 0-1
* @var float
*/
protected $_value;
/**
* 构造
* @param float $hue 色相
* @param float $saturation 饱和度
* @param float $value 色调
*/
public function __construct($hue=0, $saturation=0, $value=0) {
$this->_hue = $hue;
$this->_saturation = $saturation;
$this->_value = $value;
}
/**
* 获取色相 0-360
* @return float
*/
public function getHue() {
return $this->_hue;
}
/**
* 获取饱和度 0-1
* @return float
*/
public function getSaturation() {
return $this->_saturation;
}
/**
* 获取色调 0-1
* @return float
*/
public function getValue() {
return $this->_value;
}
/**
* 返回该色彩在RGB色彩空间的描述
* @return RGB
*/
public function toRGB() {
$hue = $this->getHue();
$saturation = $this->getSaturation();
$value = $this->getValue();
$hi = floor($hue / 60) % 6;
$f = $hue / 60 - $hi;
$p = $value * (1 - $saturation);
$q = $value * (1 - $f * $saturation);
$t = $value * (1 - (1 - $f) * $saturation);
switch ($hi) {
case 0:
$red = $value;
$green = $t;
$blue = $p;
break;
case 1:
$red = $q;
$green = $value;
$blue = $p;
break;
case 2:
$red = $p;
$green = $value;
$blue = $t;
break;
case 3:
$red = $p;
$green = $q;
$blue = $value;
break;
case 4:
$red = $t;
$green = $p;
$blue = $value;
break;
case 5:
$red = $value;
$green = $p;
$blue = $q;
break;
default:
throw new ErrorException('HSV Conversion RGB failure!');
break;
};
require_once 'RGB.php';
return new RGB($red, $green, $blue);
}
/**
* 返回数组形式表达
* @return array
*/
public function toArray() {
return array(
'hue' => $this->getHue(),
'saturation' => $this->getSaturation(),
'value' => $this->getValue()
);
}
}
<?php
/**
* RGB色彩空间描述
* @author shizhuolin
*/
class RGB {
/**
* 红色 0-1
* @var float
*/
protected $_red;
/**
* 绿色 0-1
* @var float
*/
protected $_green;
/**
* 蓝色 0-1
* @var float
*/
protected $_blue;
/**
* 以初始值构造
* @param float $red 红色0-1
* @param float $green 绿色0-1
* @param float $blue 蓝色0-1
*/
public function __construct($red = 0, $green = 0, $blue = 0) {
$this->_red = $red;
$this->_green = $green;
$this->_blue = $blue;
}
/**
* 获取红色分量
* @return float
*/
public function getRed() {
return $this->_red;
}
/**
* 获取绿色分量
* @return float
*/
public function getGreen() {
return $this->_green;
}
/**
* 获取蓝色分量
* @return float
*/
public function getBlue() {
return $this->_blue;
}
/**
* 返回该色彩的HSL空间描述
* @return HSL
*/
public function toHSL() {
$r = $this->getRed();
$g = $this->getGreen();
$b = $this->getBlue();
$rgb = array($r, $g, $b);
$max = max($rgb);
$min = min($rgb);
$diff = $max - $min;
if ($max == $min) {
$h = 0;
} else if ($max == $r && $g >= $b) {
$h = 60 * (($g - $b) / $diff);
} else if ($max == $r && $g < $b) {
$h = 60 * (($g - $b) / $diff) + 360;
} else if ($max == $g) {
$h = 60 * (($b - $r) / $diff) + 120;
} else if ($max == $b) {
$h = 60 * (($r - $g) / $diff) + 240;
} else {
throw new ErrorException("RGB conversion HSL failure!");
}
$l = ($max + $min) / 2;
if ($l == 0 || $max == $min) {
$s = 0;
} else if (0 < $l && $l <= 0.5) {
$s = $diff / (2 * $l);
} else if ($l > 0.5) {
$s = $diff / (2 - 2 * $l);
} else {
throw new ErrorException("RGB conversion HSL failure!");
}
require_once 'HSL.php';
return new HSL($h, $s, $l);
}
/**
* 返回此色彩的HSV空间描述
* @return HSV
*/
public function toHSV() {
$red = $this->getRed();
$green = $this->getGreen();
$blue = $this->getBlue();
$rgb = array($red, $green, $blue);
$max = max($rgb);
$min = min($rgb);
$diff = $max - $min;
/* 计算色相 */
if ($max == $min) {
$hue = 0;
} else if ($max == $red && $green >= $blue) {
$hue = 60 * (($green - $blue) / $diff);
} else if ($max == $red && $green < $blue) {
$hue = 60 * (($green - $blue) / $diff) + 360;
} else if ($max == $green) {
$hue = 60 * (($blue - $red) / $diff) + 120;
} else if ($max == $blue) {
$hue = 60 * (($red - $green) / $diff) + 240;
} else {
throw new ErrorException("compute hue failure!");
}
/* 计算饱和度 */
if ($max == 0) {
$saturation = 0;
} else {
$saturation = 1 - $min / $max;
}
/* 计算色调 */
$value = $max;
require_once 'HSV.php';
return new HSV($hue, $saturation, $value);
}
/**
* 返回该色彩的数组表现形式
*/
public function toArray() {
return array(
'red' => $this->getRed(),
'green' => $this->getGreen(),
'blue' => $this->getBlue()
);
}
}
Effect test (requires phpunit support)
<?php
require_once dirname(__FILE__) . '/../../color/RGB.php';
require_once dirname(__FILE__) . '/../../color/HSL.php';
require_once dirname(__FILE__) . '/../../color/HSV.php';
/**
* Test class for HSL.
* Generated by PHPUnit on 2011-11-29 at 16:56:17.
*/
class HSLTest extends PHPUnit_Framework_TestCase {
/**
* @var HSL
*/
protected $object;
/**
* Sets up the fixture, for example, opens a network connection.
* This method is called before a test is executed.
*/
protected function setUp() {
$this->object = new HSL(120, 1, 0.75);
}
/**
* Tears down the fixture, for example, closes a network connection.
* This method is called after a test is executed.
*/
protected function tearDown() {
}
/**
* @todo Implement testGetHue().
*/
public function testGetHue() {
$this->assertEquals(120, $this->object->getHue());
}
/**
* @todo Implement testGetSaturation().
*/
public function testGetSaturation() {
$this->assertEquals(1, $this->object->getSaturation());
}
/**
* @todo Implement testGetLightness().
*/
public function testGetLightness() {
$this->assertEquals(0.75, $this->object->getLightness());
}
/**
* @todo Implement testToRGB().
*/
public function testToRGB() {
$this->assertEquals(new RGB(0.5, 1, 0.5), $this->object->toRGB());
}
/**
* @todo Implement testToArray().
*/
public function testToArray() {
$this->assertEquals(array(
'hue' => 120,
'saturation' => 1,
'lightness' => 0.75
), $this->object->toArray());
}
}
<?php
require_once dirname(__FILE__) . '/../../color/RGB.php';
require_once dirname(__FILE__) . '/../../color/HSL.php';
require_once dirname(__FILE__) . '/../../color/HSV.php';
/**
* Test class for HSV.
* Generated by PHPUnit on 2011-11-29 at 16:49:00.
*/
class HSVTest extends PHPUnit_Framework_TestCase {
/**
* @var HSV
*/
protected $object;
/**
* Sets up the fixture, for example, opens a network connection.
* This method is called before a test is executed.
*/
protected function setUp() {
$this->object = new HSV(120, 0.5, 1);
}
/**
* Tears down the fixture, for example, closes a network connection.
* This method is called after a test is executed.
*/
protected function tearDown() {
}
/**
* @todo Implement testGetHue().
*/
public function testGetHue() {
$this->assertEquals(120, $this->object->getHue());
}
/**
* @todo Implement testGetSaturation().
*/
public function testGetSaturation() {
$this->assertEquals(0.5, $this->object->getSaturation());
}
/**
* @todo Implement testGetValue().
*/
public function testGetValue() {
$this->assertEquals(1, $this->object->getValue());
}
/**
* @todo Implement testToRGB().
*/
public function testToRGB() {
$this->assertEquals(new RGB(0.5, 1, 0.5), $this->object->toRGB());
}
/**
* @todo Implement testToArray().
*/
public function testToArray() {
$this->assertEquals(array(
'hue' => 120,
'saturation' => 0.5,
'value' => 1
), $this->object->toArray());
}
}
<?php
require_once dirname(__FILE__) . '/../../color/RGB.php';
require_once dirname(__FILE__) . '/../../color/HSL.php';
require_once dirname(__FILE__) . '/../../color/HSV.php';
/**
* Test class for RGB.
* Generated by PHPUnit on 2011-11-29 at 16:38:54.
*/
class RGBTest extends PHPUnit_Framework_TestCase {
/**
* @var RGB
*/
protected $object;
/**
* Sets up the fixture, for example, opens a network connection.
* This method is called before a test is executed.
*/
protected function setUp() {
$this->object = new RGB(0.5, 1, 0.5);
}
/**
* Tears down the fixture, for example, closes a network connection.
* This method is called after a test is executed.
*/
protected function tearDown() {
}
/**
* @todo Implement testGetRed().
*/
public function testGetRed() {
$this->assertEquals(0.5, $this->object->getRed());
}
/**
* @todo Implement testGetGreen().
*/
public function testGetGreen() {
$this->assertEquals(1, $this->object->getGreen());
}
/**
* @todo Implement testGetBlue().
*/
public function testGetBlue() {
$this->assertEquals(0.5, $this->object->getBlue());
}
/**
* @todo Implement testToHSL().
*/
public function testToHSL() {
$this->assertEquals(new HSL(120, 1, 0.75), $this->object->toHSL());
}
/**
* @todo Implement testToHSV().
*/
public function testToHSV() {
$this->assertEquals(new HSV(120, 0.5, 1), $this->object->toHSV());
}
/**
* @todo Implement testToArray().
*/
public function testToArray() {
$this->assertEquals(array(
'red' => 0.5,
'green' => 1,
'blue' => 0.5
), $this->object->toArray());
}
}Recommended study: "PHP Video Tutorial"
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