这篇文章主要介绍了PHP如何对图片处理，帮助大家更好的利用PHP处理图片，感兴趣的朋友可以了解下。
图片处理函数功能：缩放、剪切、相框、水印、锐化、旋转、翻转、透明度、反色处理并保存历史记录的思路：当有图片有改动时自动生成一张新图片
1、转Base64编码
/*** 获取图片的Base64编码(不支持url)* @param $img_file 传入本地图片地址* @return string*/function imgToBase64($img_file) {$img_base64 = '';if (file_exists($img_file)) {$app_img_file = $img_file; // 图片路径$img_info = getimagesize($app_img_file); // 取得图片的大小，类型等//echo '<pre>' . print_r($img_info, true) . '</pre><br>';list($width, $height, $type, $attr) = getimagesize($app_img_file);$fp = fopen($app_img_file, "r"); // 图片是否可读权限if ($fp) {$filesize = filesize($app_img_file);$content = fread($fp, $filesize);$file_content = chunk_split(base64_encode($content)); // base64编码switch ($type) { //判读图片类型case 1: $img_type = "gif";break;case 2: $img_type = "jpg";break;case 3: $img_type = "png";break;}$img_base64 = 'data:image/png;base64,' . $file_content;//合成图片的base64编码}fclose($fp);}else{return $img_file;}return $img_base64; //返回图片的base64} |
2、图片旋转
/*** 图片旋转* @param $src 图片地址* @param $direction 1顺时针90 2 逆时针90* @return string*/function imgturn($src, $direction = 1){$ext = pathinfo($src)['extension'];switch ($ext) {case 'gif':$img = imagecreatefromgif($src);break;case 'jpg':case 'jpeg':$img = imagecreatefromjpeg($src);break;case 'png':$img = imagecreatefrompng($src);break;default:die('图片格式错误!');break;}$width = imagesx($img);$height = imagesy($img);$img2 = imagecreatetruecolor($height, $width);//顺时针旋转90度if($direction == 1){for ($x = 0; $x < $width; $x++) {for($y=0; $y<$height; $y++) {imagecopy($img2, $img, $height - 1 - $y, $x, $x, $y, 1, 1);}}}else if($direction == 2) {//逆时针旋转90度for ($x = 0; $x < $height; $x++) {for($y = 0; $y < $width; $y++) {imagecopy($img2, $img, $x, $y, $width - 1 - $y, $x, 1, 1);}}}switch ($ext) {case 'jpg':case "jpeg":imagejpeg($img2, $src, 100);break;case "gif":imagegif($img2, $src, 100);break;case "png":imagepng($img2, $src, 100);break;default:die('图片格式错误!');break;}imagedestroy($img);imagedestroy($img2);} |
3、图片压缩
/*** 图片压缩处理* @param string $sFile 源图片路径* @param int $iWidth 自定义图片宽度* @param int $iHeight 自定义图片高度* @return string 压缩后的图片路径*/function getThumb($sFile, $iWidth, $iHeight){//图片公共路径$public_path = '';//判断该图片是否存在if(!file_exists($public_path . $sFile)) return $sFile;list($width, $height, $type, $attr) = getimagesize($sFile);if($width < $height){imgturn($sFile, 2);}//判断图片格式(图片文件后缀)$extend = explode("." , $sFile);$attach_fileext = strtolower($extend[count($extend) - 1]);if (!in_array($attach_fileext, array('jpg','png','jpeg'))){return '';}//压缩图片文件名称$sFileNameS = str_replace("." . $attach_fileext, "_" . $iWidth . '_' . $iHeight . '.' . $attach_fileext, $sFile);//判断是否已压缩图片，若是则返回压缩图片路径if(file_exists($public_path . $sFileNameS)){return $sFileNameS;}//生成压缩图片，并存储到原图同路径下resizeImage($public_path . $sFile, $public_path . $sFileNameS, $iWidth, $iHeight);if(!file_exists($public_path . $sFileNameS)){return $sFile;}return $sFileNameS;} |
4、生成目标图片
/*** 生成图片* @param string $im 源图片路径* @param string $dest 目标图片路径* @param int $maxwidth 生成图片宽* @param int $maxheight 生成图片高*/function resizeImage($im, $dest, $maxwidth, $maxheight) {$img = getimagesize($im);switch ($img[2]) {case 1:$im = @imagecreatefromgif($im);break;case 2:$im = @imagecreatefromjpeg($im);break;case 3:$im = @imagecreatefrompng($im);break;}$pic_width = imagesx($im);$pic_height = imagesy($im);$resizewidth_tag = false;$resizeheight_tag = false;if (($maxwidth && $pic_width > $maxwidth) || ($maxheight && $pic_height > $maxheight)) {if ($maxwidth && $pic_width > $maxwidth) {$widthratio = $maxwidth / $pic_width;$resizewidth_tag = true;}if ($maxheight && $pic_height > $maxheight) {$heightratio = $maxheight / $pic_height;$resizeheight_tag = true;}if ($resizewidth_tag && $resizeheight_tag) {if ($widthratio < $heightratio){$ratio = $widthratio;}else{$ratio = $heightratio;}}if ($resizewidth_tag && !$resizeheight_tag){$ratio = $widthratio;}if ($resizeheight_tag && !$resizewidth_tag){$ratio = $heightratio;}$newwidth = $pic_width * $ratio;$newheight = $pic_height * $ratio;if (function_exists("imagecopyresampled")) {$newim = imagecreatetruecolor($newwidth, $newheight);imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $pic_width, $pic_height);} else {$newim = imagecreate($newwidth, $newheight);imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $pic_width, $pic_height);}imagejpeg($newim, $dest);imagedestroy($newim);} else {imagejpeg($im, $dest);}} |
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