How to achieve color space conversion in php

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

_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() ); } }

_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() ); } }

_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)

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()); } }

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()); } }

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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