Thinkphp 生成固定宽高像素的图片处理类
jerry thinkphp 2015年11月18日
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//-----------ImageCheck.class.php------------------
<?
/*
php缩略图函数：
等比例无损压缩，可填充补充色
主持格式：bmp 、jpg 、gif、png
param:
@srcimage : 要缩小的图片
@dstimage : 要保存的图片
@dst_width: 缩小宽
@dst_height: 缩小高
@backgroundcolor: 补充色 如：#FFFFFF 支持 6位 不支持3位
*/
class ImageCheck{
public function imagezoom($srcimage,$dstimage,$dst_width,$dst_height,$backgroundcolor ){
// 中文件名乱码
if ( PHP_OS == 'WINNT' ) {
$srcimage = iconv('UTF-8','GBK',$srcimage);
$dstimage = iconv('UTF-8','GBK',$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)));
//echo $srcimage;
imagefill($dstimg, 0, 0, $color);
//dump(getimagesize($srcimage));
if ( !$arr=getimagesize($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($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',
'bmp' => 'imagebmp'
);
$suffix = strtolower(array_pop(explode('.', $dstimage ) ) );
if (!in_array($suffix,array_keys($arr))) {
echo "保存的文件名错误";
exit;
} else {
eval( $arr[$suffix] . '($dstimg, "'.$dstimage.'");' );
}
imagejpeg($dstimg,$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];
}else if( 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( $ret );
}
//***********************************************************
public function imagecreatefrombmp($filename){
if (! $f1 = fopen($filename,"rb")) return FALSE;
$FILE = unpack("vfile_type/Vfile_size/Vreserved/Vbitmap_offset", fread($f1,14));
if ($FILE['file_type'] != 19778) return FALSE;
$BMP = unpack('Vheader_size/Vwidth/Vheight/vplanes/vbits_per_pixel'.'/Vcompression/Vsize_bitmap/Vhoriz_resolution'.'/Vvert_resolution/Vcolors_used/Vcolors_important', fread($f1,40));
$BMP['colors'] = pow(2,$BMP['bits_per_pixel']);
if ($BMP['size_bitmap'] == 0) $BMP['size_bitmap'] = $FILE['file_size'] - $FILE['bitmap_offset'];
$BMP['bytes_per_pixel'] = $BMP['bits_per_pixel']/8;
$BMP['bytes_per_pixel2'] = ceil($BMP['bytes_per_pixel']);
$BMP['decal'] = ($BMP['width']*$BMP['bytes_per_pixel']/4);
$BMP['decal'] -= floor($BMP['width']*$BMP['bytes_per_pixel']/4);
$BMP['decal'] = 4-(4*$BMP['decal']);
if ($BMP['decal'] == 4) $BMP['decal'] = 0;
$PALETTE = array();
if ($BMP['colors'] < 16777216)
{
$PALETTE = unpack('V'.$BMP['colors'], fread($f1,$BMP['colors']*4));
}
$IMG = fread($f1,$BMP['size_bitmap']);
$VIDE = chr(0);
$res = imagecreatetruecolor($BMP['width'],$BMP['height']);
$P = 0;
$Y = $BMP['height']-1;
while ($Y >= 0)
{
$X=0;
while ($X < $BMP['width'])
{
if ($BMP['bits_per_pixel'] == 24)
$COLOR = unpack("V",substr($IMG,$P,3).$VIDE);
else if ($BMP['bits_per_pixel'] == 16){
$COLOR = unpack("n",substr($IMG,$P,2));
$COLOR[1] = $PALETTE[$COLOR[1]+1];
}else if ($BMP['bits_per_pixel'] == 8){
$COLOR = unpack("n",$VIDE.substr($IMG,$P,1));
$COLOR[1] = $PALETTE[$COLOR[1]+1];
}else if ($BMP['bits_per_pixel'] == 4){
$COLOR = unpack("n",$VIDE.substr($IMG,floor($P),1));
if (($P*2)%2 == 0) $COLOR[1] = ($COLOR[1] >> 4) ; else $COLOR[1] = ($COLOR[1] & 0x0F);
$COLOR[1] = $PALETTE[$COLOR[1]+1];
}else if ($BMP['bits_per_pixel'] == 1){
$COLOR = unpack("n",$VIDE.substr($IMG,floor($P),1));
if (($P*8)%8 == 0) $COLOR[1] = $COLOR[1] >>7;
elseif (($P*8)%8 == 1) $COLOR[1] = ($COLOR[1] & 0x40)>>6;
elseif (($P*8)%8 == 2) $COLOR[1] = ($COLOR[1] & 0x20)>>5;
elseif (($P*8)%8 == 3) $COLOR[1] = ($COLOR[1] & 0x10)>>4;
elseif (($P*8)%8 == 4) $COLOR[1] = ($COLOR[1] & 0x8)>>3;
elseif (($P*8)%8 == 5) $COLOR[1] = ($COLOR[1] & 0x4)>>2;
elseif (($P*8)%8 == 6) $COLOR[1] = ($COLOR[1] & 0x2)>>1;
elseif (($P*8)%8 == 7) $COLOR[1] = ($COLOR[1] & 0x1);
$COLOR[1] = $PALETTE[$COLOR[1]+1];
}else
return FALSE;
imagesetpixel($res,$X,$Y,$COLOR[1]);
$X++;
$P += $BMP['bytes_per_pixel'];
}
$Y--;
$P+=$BMP['decal'];
}
fclose($f1);
return $res;
}
//*********************************BMP保存函数*************************************************
public function imagebmp ($im, $fn = false){
if (!$im) return false;
if ($fn === false) $fn = 'php://output';
$f = fopen ($fn, "w");
if (!$f) return false;
$biWidth = imagesx ($im);
$biHeight = imagesy ($im);
$biBPLine = $biWidth * 3;
$biStride = ($biBPLine + 3) & ~3;
$biSizeImage = $biStride * $biHeight;
$bfOffBits = 54;
$bfSize = $bfOffBits + $biSizeImage;
fwrite ($f, 'BM', 2);
fwrite ($f, pack ('VvvV', $bfSize, 0, 0, $bfOffBits));
fwrite ($f, pack ('VVVvvVVVVVV',40,$biWidth, $biHeight,1,24,0, $biSizeImage,0,0,0,0));
$numpad = $biStride - $biBPLine;
for ($y = $biHeight - 1; $y >= 0; --$y)
{
for ($x = 0; $x < $biWidth; ++$x)
{
$col = imagecolorat ($im, $x, $y);
fwrite ($f, pack ('V', $col), 3);
}
for ($i = 0; $i < $numpad; ++$i)
{
fwrite ($f, pack ('C', 0));
}
fclose ($f);
return true;
}
}
}
?>
//----------调用-------------------------
$image=new ImageCheck();
$image->imagezoom("./Common/upload/news/20130712/liu.jpg","./Common/upload/news/20130712/liu.jpg",100,100,"#FFFFFF");
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