PlanarYUVLuminanceSource.php

<?php
/*
 * Copyright 2009 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

namespace Zxing;

/**
 * This object extends LuminanceSource around an array of YUV data returned from the camera driver,
 * with the option to crop to a rectangle within the full data. This can be used to exclude
 * superfluous pixels around the perimeter and speed up decoding.
 *
 * It works for any pixel format where the Y channel is planar and appears first, including
 * YCbCr_420_SP and YCbCr_422_SP.
 *
 * @author dswitkin@google.com (Daniel Switkin)
 */
final class PlanarYUVLuminanceSource extends LuminanceSource {

private static  $THUMBNAIL_SCALE_FACTOR = 2;

private $yuvData;
private $dataWidth;
private $dataHeight;
private $left;
private $top;

public function __construct($yuvData,
$dataWidth,
$dataHeight,
$left,
$top,
$width,
$height,
$reverseHorizontal) {
parent::__construct($width, $height);

if ($left + $width > $dataWidth || $top + $height > $dataHeight) {
throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
}

    $this->yuvData = $yuvData;
    $this->dataWidth = $dataWidth;
    $this->dataHeight = $dataHeight;
    $this->left = $left;
    $this->top = $top;
    if ($reverseHorizontal) {
        $this->reverseHorizontal($width, $height);
    }
  }

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

    $area = $width * $height;
    $matrix = array();//new byte[area];
    $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->yuvData, $inputOffset, $matrix, 0, $area);
        return $matrix;
    }

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

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

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

  public function renderThumbnail() {
$width = intval($this->getWidth() / self::$THUMBNAIL_SCALE_FACTOR);
    $height = intval($this->getHeight() / self::$THUMBNAIL_SCALE_FACTOR);
    $pixels = array();//new int[width * height];
    $yuv = $this->yuvData;
    $inputOffset = $this->top * $this->dataWidth + $this->left;

    for ($y = 0; $y < $height; $y++) {
    $outputOffset = $y * $width;
      for ($x = 0; $x < $width; $x++) {
        $grey = intval32bits($yuv[$inputOffset + $x * self::$THUMBNAIL_SCALE_FACTOR] & 0xff);
        $pixels[$outputOffset + $x] = intval32bits(0xFF000000 | ($grey * 0x00010101));
      }
      $inputOffset += $this->dataWidth * self::$THUMBNAIL_SCALE_FACTOR;
    }
    return $pixels;
  }

  /**
   * @return width of image from {@link #renderThumbnail()}
   */
    /*
  public int getThumbnailWidth() {
    return getWidth() / THUMBNAIL_SCALE_FACTOR;
  }*/

  /**
   * @return height of image from {@link #renderThumbnail()}
   */
    /*
  public int getThumbnailHeight() {
    return getHeight() / THUMBNAIL_SCALE_FACTOR;
  }

  private void reverseHorizontal(int width, int height) {
    byte[] yuvData = this.yuvData;
    for (int y = 0, rowStart = top * dataWidth + left; y < height; y++, rowStart += dataWidth) {
        int middle = rowStart + width / 2;
      for (int x1 = rowStart, x2 = rowStart + width - 1; x1 < middle; x1++, x2--) {
            byte temp = yuvData[x1];
        yuvData[x1] = yuvData[x2];
        yuvData[x2] = temp;
      }
    }
  }
*/
}