/**
* Get the distance from this point to point $q
* @param OpticsPoint $q
* @return float
*/
public function distanceTo(OpticsPoint $q)
{
$sumMe = array();
for ($i = $this->_optics->getPointDimensions() - 1; $i >= 0; $i--) {
$sumMe[] = pow($this->getPointDimension($i) - $q->getPointDimension($i), 2);
}
return sqrt(array_sum($sumMe));
}
/**
* Haversine (Earth, Miles)
* Point should be array(Lat, Long)
* @link en.wikipedia.org/wiki/Haversine_formula
* @param OpticsSpherePoint $q
*/
public function distanceTo(OpticsPoint $q)
{
//Check for 0 distance
$first = $this->getPointDimension();
$second = $q->getPointDimension();
if ($first === $second) {
return 0;
}
$first[0] = 0.01745 * $first[0];
$second[0] = 0.01745 * $second[0];
$a = sin(($second[0] - $first[0]) / 2.0);
$b = sin(0.01745 * ($second[1] - $first[1]) / 2.0);
return 7926.3352 * asin(sqrt($a * $a + cos($first[0]) * cos($second[0]) * $b * $b));
}
/**
* Color Distance CeiDe2000
* Based on:
* @link http://www.ece.rochester.edu/~gsharma/ciede2000/ciede2000noteCRNA.pdf
* @param OpticsColorPoint $q
*/
public function distanceTo(OpticsPoint $q)
{
//Check for 0 distance
if ($this->getPointDimension() === $q->getPointDimension()) {
return 0;
}
$kl = $kc = $kh = 1.0;
$barL = ($this->l + $q->l) / 2.0;
//(Numbers corrispond to http://www.ece.rochester.edu/~gsharma/ciede2000/ciede2000noteCRNA.pdf eq)
//2
$helperB1Sq = pow($this->b, 2);
$helperB2Sq = pow($q->b, 2);
$c1 = sqrt(pow($this->a, 2) + $helperB1Sq);
$c2 = sqrt(pow($q->a, 2) + $helperB2Sq);
//3
$barC = ($c1 + $c2) / 2.0;
//4
$helperPow7 = sqrt(pow($barC, 7) / (pow($barC, 7) + 6103515625));
$g = 0.5 * (1 - $helperPow7);
//5
$primeA1 = (1 + $g) * $this->a;
$primeA2 = (1 + $g) * $q->a;
//6
$primeC1 = sqrt(pow($primeA1, 2) + $helperB1Sq);
$primeC2 = sqrt(pow($primeA2, 2) + $helperB2Sq);
//7
if ($this->b === 0 && $primeA1 === 0) {
$primeH1 = 0;
} else {
$primeH1 = (atan2($this->b, $primeA1) + 2 * M_PI) * (180 / M_PI);
}
if ($q->b === 0 && $primeA2 === 0) {
$primeH2 = 0;
} else {
$primeH2 = (atan2($q->b, $primeA2) + 2 * M_PI) * (180 / M_PI);
}
//8
$deltaLPrime = $q->l - $this->l;
//9
$deltaCPrime = $primeC2 - $primeC1;
//10
$helperH = $primeH2 - $primeH1;
if ($primeC1 * $primeC2 === 0) {
$deltahPrime = 0;
} else {
if (abs($helperH) <= 180) {
$deltahPrime = $helperH;
} else {
if ($helperH > 180) {
$deltahPrime = $helperH - 360.0;
} else {
if ($helperH < -180) {
$deltahPrime = $helperH + 360.0;
} else {
throw new Exception('Invalid delta h\'');
}
}
}
}
//11
$deltaHPrime = 2 * sqrt($primeC1 * $primeC2) * sin($deltahPrime / 2.0 * (M_PI / 180));
//12
$barLPrime = ($this->l + $q->l) / 2.0;
//13
$barCPrime = ($primeC1 + $primeC2) / 2.0;
//14
$helperH = abs($primeH1 - $primeH2);
if ($primeC1 * $primeC2 === 0) {
$barHPrime = $primeH1 + $primeH2;
} else {
if ($helperH <= 180) {
$barHPrime = ($primeH1 + $primeH2) / 2.0;
} else {
if ($helperH > 180 && $primeH1 + $primeH2 < 360) {
$barHPrime = ($primeH1 + $primeH2 + 360) / 2.0;
} else {
if ($helperH > 180 && $primeH1 + $primeH2 >= 360) {
$barHPrime = ($primeH1 + $primeH2 - 360) / 2.0;
} else {
throw new Exception('Invalid bar h\'');
}
}
}
}
//15
$t = 1 - 0.17 * cos(($barHPrime - 30) * (M_PI / 180)) + 0.24 * cos(2 * $barHPrime * (M_PI / 180)) + 0.32 * cos((3 * $barHPrime + 6) * (M_PI / 180)) - 0.2 * cos((4 * $barHPrime - 63) * (M_PI / 180));
//16
$deltaTheta = 30 * exp(-1 * pow(($barHPrime - 275) / 25, 2));
//17
$rc = 2 * $helperPow7;
//18
$slHelper = pow($barLPrime - 50, 2);
$sl = 1 + 0.015 * $slHelper / sqrt(20 + $slHelper);
//19
$sc = 1 + 0.046 * $barCPrime;
//20
$sh = 1 + 0.015 * $barCPrime * $t;
//21
$rt = -1 * sin(2 * $deltaTheta * (M_PI / 180)) * $rc;
//22
$deltaESquared = pow($deltaLPrime / ($kl * $sl), 2) + pow($deltaCPrime / ($kc * $sc), 2) + pow($deltaHPrime / ($kh * $sh), 2) + $rt * ($deltaCPrime / ($kc * $sc)) * ($deltaHPrime / ($kh * $sh));
$deltaE = sqrt($deltaESquared);
return $deltaE;
}