/**
* Calculates and stores requested pixel's Delta E in relation to comparison pixel
*
* @since 2.0
* @param SLIRImage $image
* @param integer $xA x-axis position of pixel to calculate
* @param integer $yA y-axis position of pixel to calculate
* @param integer $xMove number of pixels to move on the x-axis to find comparison pixel
* @param integer $yMove number of pixels to move on the y-axis to find comparison pixel
* @return boolean
*/
private function calculateDelta(SLIRImage $image, $xA, $yA, $xMove, $yMove)
{
$xB = $xA + $xMove;
$yB = $yA + $yMove;
// Pixel is outside of the image, so we cant't calculate the Delta E
if ($xB < 0 || $xB >= $image->getWidth() || $yB < 0 || $yB >= $image->getHeight()) {
return null;
}
if (!isset($this->colors[$xA][$yA][self::PIXEL_LAB])) {
$this->loadPixelInfo($image, $xA, $yA);
}
if (!isset($this->colors[$xB][$yB][self::PIXEL_LAB])) {
$this->loadPixelInfo($image, $xB, $yB);
}
$delta = $this->deltaE($this->colors[$xA][$yA][self::PIXEL_LAB], $this->colors[$xB][$yB][self::PIXEL_LAB]);
$this->colors[$xA][$yA][self::PIXEL_DELTA_E]["d{$xMove}{$yMove}"] = $delta;
$xBMove = $xMove * -1;
$yBMove = $yMove * -1;
$this->colors[$xB][$yB][self::PIXEL_DELTA_E]["d{$xBMove}{$yBMove}"] =& $this->colors[$xA][$yA][self::PIXEL_DELTA_E]["d{$xMove}{$yMove}"];
return true;
}
/**
* @since 2.0
* @param SLIRImage $image
* @return integer
*/
public function getCropY(SLIRImage $image)
{
return round(($image->getHeight() - $image->getCropHeight()) / 2);
}