$luminances
$luminances
This class is used to help decode images from files which arrive as GD Resource It does not support rotation.
getMatrix() : \Zxing\A
Fetches luminance data for the underlying bitmap. Values should be fetched using: {@code int luminance = array[y * width + x] & 0xff}
row-major 2D array of luminance values. Do not use result.length as it may be larger than width * height bytes on some platforms. Do not modify the contents of the result.
crop(mixed $left, mixed $top, mixed $width, mixed $height) : \Zxing\A
Returns a new object with cropped image data. Implementations may keep a reference to the original data rather than a copy. Only callable if isCropSupported() is true.
| mixed | $left | |
| mixed | $top | |
| mixed | $width | |
| mixed | $height |
cropped version of this object.
getRow(mixed $y, mixed $row = null) : array
Fetches one row of luminance data from the underlying platform's bitmap. Values range from 0 (black) to 255 (white). Because Java does not have an unsigned byte type, callers will have to bitwise and with 0xff for each value. It is preferable for implementations of this method to only fetch this row rather than the whole image, since no 2D Readers may be installed and getMatrix() may never be called.
| mixed | $y | ; The row to fetch, which must be in [0,getHeight()) |
| mixed | $row | ; An optional preallocated array. If null or too small, it will be ignored. Always use the returned object, and ignore the .length of the array. |
An array containing the luminance data.
<?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);
}
}