我想在Imagepress中使用ImageMagick对某个缩略图大小进行一些自定义处理，超出正常的Wordpress功能，我不太清楚如何去做。
所以我添加了我的新缩略图大小：
add_image_size( 'new-thumb', 100, 100 );
然后这就是我不知道应该在哪里进入的地方。在缩略图的最终副本保存在Wordpress中之前，我想对其进行一些自定义处理。我想要的基本伪代码是：
The_hook_or_action_that_fires_when_a_thumbnail_is_saved() {
if (<Thumbnail Being Generated> == 'new-thumb') {
$thumb_file = 'the thumbnail image we are about to save';
$thumbfile = 'do some imagemagic stuff here';
}
save_thumbnail;
}
我可以处理imagemagick的东西，但我不知道如何/在哪里将这个自定义缩略图处理挂钩到。
任何建议都将不胜感激！
答案 0 :(得分：7)
在我的图书馆中，我有以下内容：
非常有趣的拇指名称和裁剪的操作。检查此链接中的原始Q＆amp; A。
使用：
使用：
wp_generate_attachment_metadata 使用：
使用：
使用：
wp_handle_upload_prefilter wp_handle_upload和L#466 upload_dir 答案 1 :(得分：7)
感谢@brasofilo指出我正确的方向......
我捅了一下，想出了这个。您可以挂钩到wp_generate_attachment_metadata并进行一些图像处理。我尝试做的基础是将图像调整为特定尺寸（“品牌”缩略图），然后将该缩略图的画布展开为静态高度和宽度，并带有白色背景。
如果有人有类似的情况，我想我会粘贴一些代码。可以清除它以删除每种图像类型的补充。此代码的一个问题是，如果原始图像大小小于所需的缩略图大小，则不会生成（这是WordPress功能）。
add_image_size( 'brands', 200, 168 );
add_filter('wp_generate_attachment_metadata','replace_uploaded_image');
function replace_uploaded_image($image_data) {
// if there is no brands image : return
if ( !isset($image_data['sizes']['brands']) )
return $image_data;
//Set our desired static height / width (200px * 168px)
$staticWidth = 200;
$staticHeight = 168;
// paths to the uploaded image and the large image
$upload_dir = wp_upload_dir();
$brands_image_location = $upload_dir['path'] . '/' . $image_data['sizes']['brands']['file'];
// set our temp image file
$brands_image_location_tmp = "$brands_image_location.tmp";
// get the attributes of the source image
list($imageWidth, $imageHeight, $imageType, $imageAttr) = getimagesize($brands_image_location);
// there are different php functions depending on what type of image it is, so check the type
switch($imageType) {
//GIF
case 1:
//Create a 200x168 white canvas
$newimage=imagecreatetruecolor($staticWidth,$staticHeight);
$white=imagecolorallocate($newimage, 255, 255, 255);
imagefill($newimage,0,0,$white);
//Calculate where the image should start so its centered
if($imageWidth == $staticWidth) { $x_pos = 0; } else { $x_pos = round( ($staticWidth - $imageWidth) / 2 ); }
if($imageHeight == $staticHeight) { $y_pos = 0; } else { $y_pos = round( ($staticHeight - $imageHeight) / 2 ); }
//Copy the source image to the new canvas
$src = imagecreatefromgif($brands_image_location);
imagecopy($newimage, $src, $x_pos, $y_pos, 0, 0, $imageWidth, $imageHeight);
imagegif($newimage,$brands_image_location_tmp);
// delete the uploaded image
unlink($brands_image_location);
// rename the temporary brands image
rename($brands_image_location_tmp, $brands_image_location);
// update image metadata and return them
$image_data['sizes']['brands']['width'] = $staticWidth;
$image_data['sizes']['brands']['height'] = $staticHeight;
break;
//JPG
case 2:
//Create a 200x168 white canvas
$newimage=imagecreatetruecolor($staticWidth,$staticHeight);
$white=imagecolorallocate($newimage, 255, 255, 255);
imagefill($newimage,0,0,$white);
//Calculate where the image should start so its centered
if($imageWidth == $staticWidth) { $x_pos = 0; } else { $x_pos = round( ($staticWidth - $imageWidth) / 2 ); }
if($imageHeight == $staticHeight) { $y_pos = 0; } else { $y_pos = round( ($staticHeight - $imageHeight) / 2 ); }
//Copy the source image to the new canvas
$src = imagecreatefromjpeg($brands_image_location);
imagecopy($newimage, $src, $x_pos, $y_pos, 0, 0, $imageWidth, $imageHeight);
imagejpeg($newimage,$brands_image_location_tmp);
// delete the uploaded image
unlink($brands_image_location);
// rename the temporary brands image
rename($brands_image_location_tmp, $brands_image_location);
// update image metadata and return them
$image_data['sizes']['brands']['width'] = $staticWidth;
$image_data['sizes']['brands']['height'] = $staticHeight;
break;
//PNG
case 3:
//Create a 200x168 white canvas
$newimage=imagecreatetruecolor($staticWidth,$staticHeight);
$white=imagecolorallocate($newimage, 255, 255, 255);
imagefill($newimage,0,0,$white);
//Calculate where the image should start so its centered
if($imageWidth == $staticWidth) { $x_pos = 0; } else { $x_pos = round( ($staticWidth - $imageWidth) / 2 ); }
if($imageHeight == $staticHeight) { $y_pos = 0; } else { $y_pos = round( ($staticHeight - $imageHeight) / 2 ); }
//Copy the source image to the new canvas
$src = imagecreatefrompng($brands_image_location);
imagecopy($newimage, $src, $x_pos, $y_pos, 0, 0, $imageWidth, $imageHeight);
imagepng($newimage,$brands_image_location_tmp);
// delete the uploaded image
unlink($brands_image_location);
// rename the temporary brands image
rename($brands_image_location_tmp, $brands_image_location);
// update image metadata and return them
$image_data['sizes']['brands']['width'] = $staticWidth;
$image_data['sizes']['brands']['height'] = $staticHeight;
break;
}
return $image_data;
}
答案 2 :(得分：2)
我想建议更改，以使其与缩略图重新生成插件一起使用
$upload_dir = wp_upload_dir();
$brands_image_location = $upload_dir['basedir'].'/'.dirname($image_data['file']) . '/' . $image_data['sizes']['brands']['file'];
$brands_image_location = $brands_image_location.'.tmp';
之所以如此，是因为wp_upload_dir返回当前年月的路径，但一些以前上传的图片可能有不同的路径。