How to implement image format conversion in php-PHP Problem-php.cn

How to implement image format conversion in php

coldplay.xixi

Release： 2023-03-05 07:30:01

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php method to implement image format conversion: first convert and save in [test.png], the code is [transform_image($url, 'png', './test.png')]; then convert The binary result is returned directly.

How to implement image format conversion in php

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php implementation pictures Method of format conversion:

During the development process, there will always be some requirements that require conversion of image formats. For example, gif to png, jpg to png

If you have recently used a certain platform's image file recognition, but it does not support the gif format, then you need to process the gif into png, etc.

Depends on

php extends gd and exif

implementation

/**
 * 图片格式转换
 * @param string $image_path 文件路径或url
 * @param string $to_ext 待转格式，支持png,gif,jpeg,wbmp,webp,xbm
 * @param null|string $save_path 存储路径，null则返回二进制内容，string则返回true|false
 * @return boolean|string $save_path是null则返回二进制内容，是string则返回true|false
 * @throws Exception 
 * @author klinson <klinson@163.com>
 */
function transform_image($image_path, $to_ext = &#39;png&#39;, $save_path = null)
{
  if (! in_array($to_ext, [&#39;png&#39;, &#39;gif&#39;, &#39;jpeg&#39;, &#39;wbmp&#39;, &#39;webp&#39;, &#39;xbm&#39;])) {
    throw new \Exception(&#39;unsupport transform image to &#39; . $to_ext);
  }
  switch (exif_imagetype($image_path)) {
    case IMAGETYPE_GIF :
      $img = imagecreatefromgif($image_path);
      break;
    case IMAGETYPE_JPEG :
    case IMAGETYPE_JPEG2000:
      $img = imagecreatefromjpeg($image_path);
      break;
    case IMAGETYPE_PNG:
      $img = imagecreatefrompng($image_path);
      break;
    case IMAGETYPE_BMP:
    case IMAGETYPE_WBMP:
      $img = imagecreatefromwbmp($image_path);
      break;
    case IMAGETYPE_XBM:
      $img = imagecreatefromxbm($image_path);
      break;
    case IMAGETYPE_WEBP: //(从 PHP 7.1.0 开始支持)
      $img = imagecreatefromwebp($image_path);
      break;
    default :
      throw new \Exception(&#39;Invalid image type&#39;);
  }
  $function = &#39;image&#39;.$to_ext;
  if ($save_path) {
    return $function($img, $save_path);
  } else {
    $tmp = __DIR__.&#39;/&#39;.uniqid().&#39;.&#39;.$to_ext;
    if ($function($img, $tmp)) {
      $content = file_get_contents($tmp);
      unlink($tmp);
      return $content;
    } else {
      unlink($tmp);
      throw new \Exception(&#39;the file &#39;.$tmp.&#39; can not write&#39;);
    }
  }
}

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use

// 转换后保存在test.png
transform_image($url, &#39;png&#39;, &#39;./test.png&#39;);
transform_image($filepath, &#39;png&#39;, &#39;./test.png&#39;);
// 转换后二进制结果直接返回
transform_image($url, &#39;png&#39;);
transform_image($filepath, &#39;png&#39;);

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