php等比例压缩图片(jpg,jif,png图片等比例压缩)

$maxWidth) {    $maxWidth = $maxWidth;    if($srcHeight > $maxHeight) {     $maxHeight = ($srcHeight/$srcHeight) * $maxWidth;    } else {      $maxHeight = $srcHeight;    }    return array('width' => $maxWidth,'height' => $maxHeight);   }      if($srcHeight > $maxHeight) {    $maxHeight = $maxHeight;    if($srcWidth > $maxWidth) {      $maxWidth = ($srcWidth/$srcHeight) * $maxHeight;    } else {      $maxWidth = $srcWidth;    }    return array('width' => $srcWidth,'height' => $maxHeight);   }      return array('width' => $srcWidth,'height' => $srcHeight);

 }  /**   * 等比例生成缩略图   *   * @param  String  $srcFile  原始文件路径   * @param  String  $dstFile  目标文件路径   * @param  Integer  $maxWidth  生成的目标文件的最大宽度   * @param  Integer  $maxHeight  生成的目标文件的最大高度   * @return  Boolean  生成成功则返回true，否则返回false   */  function makeThumb($srcFile, $dstFile, $maxWidth, $maxHeight) {   if ($size = getimagesize($srcFile)) {    $srcWidth = $size[0];    $srcHeight = $size[1];    $mime = $size['mime'];

   switch ($mime) {     case 'image/jpeg';      $isJpeg = true;      break;     case 'image/gif';      $isGif = true;      break;     case 'image/png';      $isPng = true;      break;     default:      return false;      break;    }    //header("Content-type:$mime");    $arr = $this->getNewSize($maxWidth, $maxHeight, $srcWidth, $srcHeight);    $thumbWidth = $arr['width'];    $thumbHeight = $arr['height'];    if (isset($isJpeg) && $isJpeg) {     $dstThumbPic = imagecreatetruecolor($thumbWidth, $thumbHeight);     $srcPic = imagecreatefromjpeg($srcFile);     imagecopyresampled($dstThumbPic, $srcPic, 0, 0, 0, 0, $thumbWidth, $thumbHeight, $srcWidth, $srcHeight);     imagejpeg($dstThumbPic, $dstFile, 100);     imagedestroy($dstThumbPic);     imagedestroy($srcPic);     return true;    } elseif (isset($isGif) && $isGif) {     $dstThumbPic = imagecreatetruecolor($thumbWidth, $thumbHeight);     //创建透明画布     imagealphablending($dstThumbPic, true);     imagesavealpha($dstThumbPic, true);     $trans_colour = imagecolorallocatealpha($dstThumbPic, 0, 0, 0, 127);     imagefill($dstThumbPic, 0, 0, $trans_colour);

    $srcPic = imagecreatefromgif($srcFile);     imagecopyresampled($dstThumbPic, $srcPic, 0, 0, 0, 0, $thumbWidth, $thumbHeight, $srcWidth, $srcHeight);     imagegif($dstThumbPic, $dstFile);     imagedestroy($dstThumbPic);     imagedestroy($srcPic);     return true;    } elseif (isset($isPng) && $isPng) {     $dstThumbPic = imagecreatetruecolor($thumbWidth, $thumbHeight);     //创建透明画布     imagealphablending($dstThumbPic, true);     imagesavealpha($dstThumbPic, true);     $trans_colour = imagecolorallocatealpha($dstThumbPic, 0, 0, 0, 127);     imagefill($dstThumbPic, 0, 0, $trans_colour);

    $srcPic = imagecreatefrompng($srcFile);     imagecopyresampled($dstThumbPic, $srcPic, 0, 0, 0, 0, $thumbWidth, $thumbHeight, $srcWidth, $srcHeight);     imagepng($dstThumbPic, $dstFile);     imagedestroy($dstThumbPic);     imagedestroy($srcPic);     return true;    } else {     return false;    }   } else {    return false;   }  } } ?>