GDLuminanceSource.php

<?php


namespace Zxing;

/**
 * This class is used to help decode images from files which arrive as GD Resource
 * It does not support rotation.
 *
 *
 *
 */
final class GDLuminanceSource extends LuminanceSource
{
    public $luminances;
    private $dataWidth;
    private $dataHeight;
    private $left;
    private $top;
    private $gdImage;

    public function __construct(
        $gdImage,
        $dataWidth,
        $dataHeight,
        $left = null,
        $top = null,
        $width = null,
        $height = null
    ) {
        if (!$left && !$top && !$width && !$height) {
            $this->GDLuminanceSource($gdImage, $dataWidth, $dataHeight);

            return;
        }
        parent::__construct($width, $height);
        if ($left + $width > $dataWidth || $top + $height > $dataHeight) {
            throw new \InvalidArgumentException("Crop rectangle does not fit within image data.");
        }
        $this->luminances = $gdImage;
        $this->dataWidth  = $dataWidth;
        $this->dataHeight = $dataHeight;
        $this->left       = $left;
        $this->top        = $top;
    }

    public function GDLuminanceSource($gdImage, $width, $height)
    {
        parent::__construct($width, $height);

        $this->dataWidth  = $width;
        $this->dataHeight = $height;
        $this->left       = 0;
        $this->top        = 0;
        $this->$gdImage   = $gdImage;


// In order to measure pure decoding speed, we convert the entire image to a greyscale array
// up front, which is the same as the Y channel of the YUVLuminanceSource in the real app.
        $this->luminances = [];
        //$this->luminances = $this->grayScaleToBitmap($this->grayscale());

        $array = [];
        $rgb   = [];

        for ($j = 0; $j < $height; $j++) {
            for ($i = 0; $i < $width; $i++) {
                $argb  = imagecolorat($this->$gdImage, $i, $j);
                $pixel = imagecolorsforindex($this->$gdImage, $argb);
                $r     = $pixel['red'];
                $g     = $pixel['green'];
                $b     = $pixel['blue'];
                if ($r == $g && $g == $b) {
// Image is already greyscale, so pick any channel.

                    $this->luminances[] = $r;//(($r + 128) % 256) - 128;
                } else {
// Calculate luminance cheaply, favoring green.
                    $this->luminances[] = ($r + 2 * $g + $b) / 4;//(((($r + 2 * $g + $b) / 4) + 128) % 256) - 128;
                }
            }
        }

        /*
        for ($y = 0; $y < $height; $y++) {
            $offset = $y * $width;
            for ($x = 0; $x < $width; $x++) {
                $pixel = $pixels[$offset + $x];
                $r = ($pixel >> 16) & 0xff;
                $g = ($pixel >> 8) & 0xff;
                $b = $pixel & 0xff;
                if ($r == $g && $g == $b) {
// Image is already greyscale, so pick any channel.

                    $this->luminances[(int)($offset + $x)] = (($r+128) % 256) - 128;
                } else {
// Calculate luminance cheaply, favoring green.
                    $this->luminances[(int)($offset + $x)] =  (((($r + 2 * $g + $b) / 4)+128)%256) - 128;
                }



            }
        */
        //}
        //   $this->luminances = $this->grayScaleToBitmap($this->luminances);
    }

//@Override
    public function getRow($y, $row = null)
    {
        if ($y < 0 || $y >= $this->getHeight()) {
            throw new \InvalidArgumentException('Requested row is outside the image: ' . $y);
        }
        $width = $this->getWidth();
        if ($row == null || count($row) < $width) {
            $row = [];
        }
        $offset = ($y + $this->top) * $this->dataWidth + $this->left;
        $row    = arraycopy($this->luminances, $offset, $row, 0, $width);

        return $row;
    }

//@Override
    public function getMatrix()
    {
        $width  = $this->getWidth();
        $height = $this->getHeight();

// If the caller asks for the entire underlying image, save the copy and give them the
// original data. The docs specifically warn that result.length must be ignored.
        if ($width == $this->dataWidth && $height == $this->dataHeight) {
            return $this->luminances;
        }

        $area        = $width * $height;
        $matrix      = [];
        $inputOffset = $this->top * $this->dataWidth + $this->left;

// If the width matches the full width of the underlying data, perform a single copy.
        if ($width == $this->dataWidth) {
            $matrix = arraycopy($this->luminances, $inputOffset, $matrix, 0, $area);

            return $matrix;
        }

// Otherwise copy one cropped row at a time.
        $rgb = $this->luminances;
        for ($y = 0; $y < $height; $y++) {
            $outputOffset = $y * $width;
            $matrix       = arraycopy($rgb, $inputOffset, $matrix, $outputOffset, $width);
            $inputOffset  += $this->dataWidth;
        }

        return $matrix;
    }

//@Override
    public function isCropSupported()
    {
        return true;
    }

//@Override
    public function crop($left, $top, $width, $height)
    {
        return new GDLuminanceSource($this->luminances,
            $this->dataWidth,
            $this->dataHeight,
            $this->left + $left,
            $this->top + $top,
            $width,
            $height);
    }
}