ColorThief\ColorThief::loadImage PHP Method

    private static function loadImage($sourceImage, $quality, array $area = null)
    {
        $loader = new ImageLoader();
        $image = $loader->load($sourceImage);
        $startX = 0;
        $startY = 0;
        $width = $image->getWidth();
        $height = $image->getHeight();
        if ($area) {
            $startX = isset($area['x']) ? $area['x'] : 0;
            $startY = isset($area['y']) ? $area['y'] : 0;
            $width = isset($area['w']) ? $area['w'] : $width - $startX;
            $height = isset($area['h']) ? $area['h'] : $height - $startY;
            if ($startX + $width > $image->getWidth() || $startY + $height > $image->getHeight()) {
                throw new \InvalidArgumentException("Area is out of image bounds.");
            }
        }
        $pixelCount = $width * $height;
        // Store the RGB values in an array format suitable for quantize function
        // SplFixedArray is faster and more memory-efficient than normal PHP array.
        $pixelArray = new SplFixedArray(ceil($pixelCount / $quality));
        $size = 0;
        for ($i = 0; $i < $pixelCount; $i = $i + $quality) {
            $x = $startX + $i % $width;
            $y = (int) ($startY + $i / $width);
            $color = $image->getPixelColor($x, $y);
            if (static::isClearlyVisible($color) && static::isNonWhite($color)) {
                $pixelArray[$size++] = static::getColorIndex($color->red, $color->green, $color->blue, 8);
                // TODO : Compute directly the histogram here ? (save one iteration over all pixels)
            }
        }
        $pixelArray->setSize($size);
        // Don't destroy a resource passed by the user !
        // TODO Add a method in ImageLoader to know if the image should be destroy (or to know the detected image source type)
        if (is_string($sourceImage)) {
            $image->destroy();
        }
        return $pixelArray;
    }