public function count($force = false)
{
if (!$this->count_set || $force) {
$npix = 0;
// Select the fastest way (i.e. with the fewest iterations) to count
// the number of pixels contained in this vbox.
if ($this->volume() > count($this->histo)) {
// Iterate over the histogram if the size of this histogram is lower than the vbox volume
foreach ($this->histo as $rgb => $count) {
$rgb_array = ColorThief::getColorsFromIndex($rgb, 0, ColorThief::SIGBITS);
if ($this->contains($rgb_array, 0)) {
$npix += $count;
}
}
} else {
// Or iterate over points of the vbox if the size of the histogram is greater than the vbox volume
for ($i = $this->r1; $i <= $this->r2; $i++) {
for ($j = $this->g1; $j <= $this->g2; $j++) {
for ($k = $this->b1; $k <= $this->b2; $k++) {
$index = ColorThief::getColorIndex($i, $j, $k);
if (isset($this->histo[$index])) {
$npix += $this->histo[$index];
}
}
}
}
}
$this->count = $npix;
$this->count_set = true;
}
return $this->count;
}
