PHP缩略图等比例无损压缩，可填充空白区域补充色_php技巧

 <BR><?php <BR>error_reporting( E_ALL ); <BR>// 测试 <BR>imagezoom('1.jpg', '2.jpg', 400, 300, '#FFFFFF'); <BR>/* <BR>php缩略图函数： <BR>等比例无损压缩，可填充补充色 author: 华仔 <BR>主持格式： <BR>bmp 、jpg 、gif、png <BR>param: <BR>@srcimage : 要缩小的图片 <BR>@dstimage : 要保存的图片 <BR>@dst_width: 缩小宽 <BR>@dst_height: 缩小高 <BR>@backgroundcolor: 补充色 如：#FFFFFF 支持 6位 不支持3位 <BR>*/ <BR>function imagezoom( $srcimage, $dstimage, $dst_width, $dst_height, $backgroundcolor ) { <BR>// 中文件名乱码 <BR>if ( PHP_OS == 'WINNT' ) { <BR>$srcimage = iconv('UTF-8', 'GBK', $srcimage); <BR>$dstimage = iconv('UTF-8', 'GBK', $dstimage); <BR>} <BR>$dstimg = imagecreatetruecolor( $dst_width, $dst_height ); <BR>$color = imagecolorallocate($dstimg <BR>, hexdec(substr($backgroundcolor, 1, 2)) <BR>, hexdec(substr($backgroundcolor, 3, 2)) <BR>, hexdec(substr($backgroundcolor, 5, 2)) <BR>); <BR>imagefill($dstimg, 0, 0, $color); <BR>if ( !$arr=getimagesize($srcimage) ) { <BR>echo "要生成缩略图的文件不存在"; <BR>exit; <BR>} <BR>$src_width = $arr[0]; <BR>$src_height = $arr[1]; <BR>$srcimg = null; <BR>$method = getcreatemethod( $srcimage ); <BR>if ( $method ) { <BR>eval( '$srcimg = ' . $method . ';' ); <BR>} <BR>$dst_x = 0; <BR>$dst_y = 0; <BR>$dst_w = $dst_width; <BR>$dst_h = $dst_height; <BR>if ( ($dst_width / $dst_height - $src_width / $src_height) > 0 ) { <BR>$dst_w = $src_width * ( $dst_height / $src_height ); <BR>$dst_x = ( $dst_width - $dst_w ) / 2; <BR>} elseif ( ($dst_width / $dst_height - $src_width / $src_height) < 0 ) { <BR>$dst_h = $src_height * ( $dst_width / $src_width ); <BR>$dst_y = ( $dst_height - $dst_h ) / 2; <BR>} <BR>imagecopyresampled($dstimg, $srcimg, $dst_x <BR>, $dst_y, 0, 0, $dst_w, $dst_h, $src_width, $src_height); <BR>// 保存格式 <BR>$arr = array( <BR>'jpg' => 'imagejpeg' <BR>, 'jpeg' => 'imagejpeg' <BR>, 'png' => 'imagepng' <BR>, 'gif' => 'imagegif' <BR>, 'bmp' => 'imagebmp' <BR>); <BR>$suffix = strtolower( array_pop(explode('.', $dstimage ) ) ); <BR>if (!in_array($suffix, array_keys($arr)) ) { <BR>echo "保存的文件名错误"; <BR>exit; <BR>} else { <BR>eval( $arr[$suffix] . '($dstimg, "'.$dstimage.'");' ); <BR>} <BR>imagejpeg($dstimg, $dstimage); <BR>imagedestroy($dstimg); <BR>imagedestroy($srcimg); <BR>} <BR>function getcreatemethod( $file ) { <BR>$arr = array( <BR>'474946' => "imagecreatefromgif('$file')" <BR>, 'FFD8FF' => "imagecreatefromjpeg('$file')" <BR>, '424D' => "imagecreatefrombmp('$file')" <BR>, '89504E' => "imagecreatefrompng('$file')" <BR>); <BR>$fd = fopen( $file, "rb" ); <BR>$data = fread( $fd, 3 ); <BR>$data = str2hex( $data ); <BR>if ( array_key_exists( $data, $arr ) ) { <BR>return $arr[$data]; <BR>} elseif ( array_key_exists( substr($data, 0, 4), $arr ) ) { <BR>return $arr[substr($data, 0, 4)]; <BR>} else { <BR>return false; <BR>} <BR>} <BR>function str2hex( $str ) { <BR>$ret = ""; <BR>for( $i = 0; $i < strlen( $str ) ; $i++ ) { <BR>$ret .= ord($str[$i]) >= 16 ? strval( dechex( ord($str[$i]) ) ) <BR>: '0'. strval( dechex( ord($str[$i]) ) ); <BR>} <BR>return strtoupper( $ret ); <BR>} <BR>// BMP 创建函数 php本身无 <BR>function imagecreatefrombmp($filename) <BR>{ <BR>if (! $f1 = fopen($filename,"rb")) return FALSE; <BR>$FILE = unpack("vfile_type/Vfile_size/Vreserved/Vbitmap_offset", fread($f1,14)); <BR>if ($FILE['file_type'] != 19778) return FALSE; <BR>$BMP = unpack('Vheader_size/Vwidth/Vheight/vplanes/vbits_per_pixel'. <BR>'/Vcompression/Vsize_bitmap/Vhoriz_resolution'. <BR>'/Vvert_resolution/Vcolors_used/Vcolors_important', fread($f1,40)); <BR>$BMP['colors'] = pow(2,$BMP['bits_per_pixel']); <BR>if ($BMP['size_bitmap'] == 0) $BMP['size_bitmap'] = $FILE['file_size'] - $FILE['bitmap_offset']; <BR>$BMP['bytes_per_pixel'] = $BMP['bits_per_pixel']/8; <BR>$BMP['bytes_per_pixel2'] = ceil($BMP['bytes_per_pixel']); <BR>$BMP['decal'] = ($BMP['width']*$BMP['bytes_per_pixel']/4); <BR>$BMP['decal'] -= floor($BMP['width']*$BMP['bytes_per_pixel']/4); <BR>$BMP['decal'] = 4-(4*$BMP['decal']); <BR>if ($BMP['decal'] == 4) $BMP['decal'] = 0; <BR>$PALETTE = array(); <BR>if ($BMP['colors'] < 16777216) <BR>{ <BR>$PALETTE = unpack('V'.$BMP['colors'], fread($f1,$BMP['colors']*4)); <BR>} <BR>$IMG = fread($f1,$BMP['size_bitmap']); <BR>$VIDE = chr(0); <BR>$res = imagecreatetruecolor($BMP['width'],$BMP['height']); <BR>$P = 0; <BR>$Y = $BMP['height']-1; <BR>while ($Y >= 0) <BR>{ <BR>$X=0; <BR>while ($X < $BMP['width']) <BR>{ <BR>if ($BMP['bits_per_pixel'] == 24) <BR>$COLOR = unpack("V",substr($IMG,$P,3).$VIDE); <BR>elseif ($BMP['bits_per_pixel'] == 16) <BR>{ <BR>$COLOR = unpack("n",substr($IMG,$P,2)); <BR>$COLOR[1] = $PALETTE[$COLOR[1]+1]; <BR>} <BR>elseif ($BMP['bits_per_pixel'] == 8) <BR>{ <BR>$COLOR = unpack("n",$VIDE.substr($IMG,$P,1)); <BR>$COLOR[1] = $PALETTE[$COLOR[1]+1]; <BR>} <BR>elseif ($BMP['bits_per_pixel'] == 4) <BR>{ <BR>$COLOR = unpack("n",$VIDE.substr($IMG,floor($P),1)); <BR>if (($P*2)%2 == 0) $COLOR[1] = ($COLOR[1] >> 4) ; else $COLOR[1] = ($COLOR[1] & 0x0F); <BR>$COLOR[1] = $PALETTE[$COLOR[1]+1]; <BR>} <BR>elseif ($BMP['bits_per_pixel'] == 1) <BR>{ <BR>$COLOR = unpack("n",$VIDE.substr($IMG,floor($P),1)); <BR>if (($P*8)%8 == 0) $COLOR[1] = $COLOR[1] >>7; <BR>elseif (($P*8)%8 == 1) $COLOR[1] = ($COLOR[1] & 0x40)>>6; <BR>elseif (($P*8)%8 == 2) $COLOR[1] = ($COLOR[1] & 0x20)>>5; <BR>elseif (($P*8)%8 == 3) $COLOR[1] = ($COLOR[1] & 0x10)>>4; <BR>elseif (($P*8)%8 == 4) $COLOR[1] = ($COLOR[1] & 0x8)>>3; <BR>elseif (($P*8)%8 == 5) $COLOR[1] = ($COLOR[1] & 0x4)>>2; <BR>elseif (($P*8)%8 == 6) $COLOR[1] = ($COLOR[1] & 0x2)>>1; <BR>elseif (($P*8)%8 == 7) $<p style="color:transparent">本文来源gao!%daima.com搞$代*!码$网3</p><strong>搞代gaodaima码</strong>COLOR[1] = ($COLOR[1] & 0x1); <BR>$COLOR[1] = $PALETTE[$COLOR[1]+1]; <BR>} <BR>else <BR>return FALSE; <BR>imagesetpixel($res,$X,$Y,$COLOR[1]); <BR>$X++; <BR>$P += $BMP['bytes_per_pixel']; <BR>} <BR>$Y--; <BR>$P+=$BMP['decal']; <BR>} <BR>fclose($f1); <BR>return $res; <BR>} <BR>// BMP 保存函数，php本身无 <BR>function imagebmp ($im, $fn = false) <BR>{ <BR>if (!$im) return false; <BR>if ($fn === false) $fn = 'php://output'; <BR>$f = fopen ($fn, "w"); <BR>if (!$f) return false; <BR>$biWidth = imagesx ($im); <BR>$biHeight = imagesy ($im); <BR>$biBPLine = $biWidth * 3; <BR>$biStride = ($biBPLine + 3) & ~3; <BR>$biSizeImage = $biStride * $biHeight; <BR>$bfOffBits = 54; <BR>$bfSize = $bfOffBits + $biSizeImage; <BR>fwrite ($f, 'BM', 2); <BR>fwrite ($f, pack ('VvvV', $bfSize, 0, 0, $bfOffBits)); <BR>fwrite ($f, pack ('VVVvvVVVVVV', 40, $biWidth, $biHeight, 1, 24, 0, $biSizeImage, 0, 0, 0, 0)); <BR>$numpad = $biStride - $biBPLine; <BR>for ($y = $biHeight - 1; $y >= 0; --$y) <BR>{ <BR>for ($x = 0; $x < $biWidth; ++$x) <BR>{ <BR>$col = imagecolorat ($im, $x, $y); <BR>fwrite ($f, pack ('V', $col), 3); <BR>} <BR>for ($i = 0; $i < $numpad; ++$i) <BR>fwrite ($f, pack ('C', 0)); <BR>} <BR>fclose ($f); <BR>return true; <BR>} <BR>?> <BR>

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