zhphp framework (二十四) 图片类 image

<?php
/**
* Created by JetBrains PhpStorm.
* User: 张华
* Date: 14-3-8
* Time: 下午12:21
* QQ: 746502560@qq.com
* To change this template use File | Settings | File Templates.
*/

final class image {
private $srcimage;
private  $dstimage;
/**
* php缩略图函数  等比例无损压缩，可填充补充色
* @param $srcimage 要缩小的图片
* @param $dstimage 要保存的图片
* @param $dst_width 缩小的宽度
* @param $dst_height 缩小的高度
* @param $backgroundcolor 补充颜色 默认为 白色
*/
public   function imagezoom( $srcimage, $dstimage,  $dst_width, $dst_height, $backgroundcolor='#ffffff' ) {
$this->fileNameGbk($srcimage, $dstimage);
$dstimg = imagecreatetruecolor( $dst_width, $dst_height );
$color = imagecolorallocate($dstimg
, hexdec(substr($backgroundcolor, 1, 2))
, hexdec(substr($backgroundcolor, 3, 2))
, hexdec(substr($backgroundcolor, 5, 2))
);
imagefill($dstimg, 0, 0, $color);

if ( !$arr=getimagesize($this->srcimage) ) {
echo "要生成缩略图的文件不存在";
exit;
}

$src_width = $arr[0];
$src_height = $arr[1];
$srcimg = null;
$method = $this->getcreatemethod( $this->srcimage );
if ( $method ) {
eval( '$srcimg = ' . $method . ';' );
}

$dst_x = 0;
$dst_y = 0;
$dst_w = $dst_width;
$dst_h = $dst_height;
if ( ($dst_width / $dst_height - $src_width / $src_height) > 0 ) {
$dst_w = $src_width * ( $dst_height / $src_height );
$dst_x = ( $dst_width - $dst_w ) / 2;
} elseif ( ($dst_width / $dst_height - $src_width / $src_height) < 0 ) {
$dst_h = $src_height * ( $dst_width / $src_width );
$dst_y = ( $dst_height - $dst_h ) / 2;
}

imagecopyresampled($dstimg, $srcimg, $dst_x
, $dst_y, 0, 0, $dst_w, $dst_h, $src_width, $src_height);

// 保存格式
$arr = array( 'jpg' => 'imagejpeg' , 'jpeg' => 'imagejpeg', 'png' => 'imagepng' , 'gif' => 'imagegif');
$suffix = strtolower( array_pop(explode('.', $this->dstimage ) ) );
if (!in_array($suffix, array_keys($arr)) ) {
echo "保存的文件名错误";
exit;
} else {
eval( $arr[$suffix] . '($dstimg, "'.$this->dstimage.'");' );
}

imagejpeg($dstimg, $this->dstimage);
imagedestroy($dstimg);
imagedestroy($srcimg);

}

public  function getcreatemethod( $file ) {
$arr = array(
'474946' => "imagecreatefromgif('$file')"
, 'FFD8FF' => "imagecreatefromjpeg('$file')"
, '424D' => "imagecreatefrombmp('$file')"
, '89504E' => "imagecreatefrompng('$file')"
);
$fd = fopen( $file, "rb" );
$data = fread( $fd, 3 );

$data = $this->str2hex($data);

if ( array_key_exists( $data, $arr ) ) {
return $arr[$data];
} elseif ( array_key_exists( substr($data, 0, 4), $arr ) ) {
return $arr[substr($data, 0, 4)];
} else {
return false;
}
}

public  function str2hex( $str ) {
$ret = "";

for( $i = 0; $i < strlen( $str ) ; $i++ ) {
$ret .= ord($str[$i]) >= 16 ? strval( dechex( ord($str[$i]) ) )
: '0'. strval( dechex( ord($str[$i]) ) );
}
return strtoupper( $ret );
}

/**
* 解决中文乱码问题
* @param $srcimage
* @param $dstimage
*/
public  function fileNameGbk($srcimage, $dstimage){
if ( PHP_OS == 'WINNT' ) {
$srcimage = iconv('UTF-8', 'GBK', $srcimage);
$dstimage = iconv('UTF-8', 'GBK', $dstimage);
}
$this->srcimage=$srcimage;
$this->dstimage=$dstimage;
}
}