protected function Face_Detector::compute_ii in Image Focus Crop 7

Same name and namespace in other branches

1. 6 php-facedetection/FaceDetector.php \Face_Detector::compute_ii()

1 call to Face_Detector::compute_ii()

Face_Detector::get_img_stats in php-facedetection/FaceDetector.php

File

php-facedetection/FaceDetector.php, line 107

Class

Face_Detector

Code

protected function compute_ii($canvas, $image_width, $image_height) {
  $ii_w = $image_width + 1;
  $ii_h = $image_height + 1;
  $ii = array();
  $ii2 = array();
  for ($i = 0; $i < $ii_w; $i++) {
    $ii[$i] = 0;
    $ii2[$i] = 0;
  }
  for ($i = 1; $i < $ii_h - 1; $i++) {
    $ii[$i * $ii_w] = 0;
    $ii2[$i * $ii_w] = 0;
    $rowsum = 0;
    $rowsum2 = 0;
    for ($j = 1; $j < $ii_w - 1; $j++) {
      $rgb = ImageColorAt($canvas, $j, $i);
      $red = $rgb >> 16 & 0xff;
      $green = $rgb >> 8 & 0xff;
      $blue = $rgb & 0xff;
      $grey = 0.2989 * $red + 0.587 * $green + 0.114 * $blue >> 0;

      // this is what matlab uses
      $rowsum += $grey;
      $rowsum2 += $grey * $grey;
      $ii_above = ($i - 1) * $ii_w + $j;
      $ii_this = $i * $ii_w + $j;
      $ii[$ii_this] = $ii[$ii_above] + $rowsum;
      $ii2[$ii_this] = $ii2[$ii_above] + $rowsum2;
    }
  }
  return array(
    'ii' => $ii,
    'ii2' => $ii2,
  );
}