如何在WordPress 3中锐化发布缩略图

Question

我使用的是Wordpress 3的默认缩略图功能，可以为我的帖子添加各种大小的缩略图。现在我面临的问题是缩小的缩略图变得非常模糊。

在.NET中，我知道如何锐化图像，这对缩略图非常有用，所以我现在正在寻找一种方法来为Wordpress（显然，在PHP中）做到这一点。

我真的很吮吸PHP，所以任何帮助真的很感激！

Answer 1

我认为这是您的答案：http://vikjavev.no/computing/ump.php, 但是，您需要更改wp中的thumbnailer创建者脚本。

Answer 2

我使用ResizeThumbnails的修改版本。这样，您就可以重新生成您的所有模糊的图像，它也需要未来的护理上传的图片：

<?php 

/* 

************************************************************************** 

Plugin Name: Regenerate Thumbnails 
Plugin URI: http://www.viper007bond.com/wordpress-plugins/regenerate-thumbnails/ 
Description: Allows you to regenerate all thumbnails after changing the thumbnail sizes. 
Version:  2.2.3 
Author:  Viper007Bond 
Author URI: http://www.viper007bond.com/ 

************************************************************************** 

Copyright (C) 2008-2011 Viper007Bond 

This program is free software: you can redistribute it and/or modify 
it under the terms of the GNU General Public License as published by 
the Free Software Foundation, either version 3 of the License, or 
(at your option) any later version. 

This program is distributed in the hope that it will be useful, 
but WITHOUT ANY WARRANTY; without even the implied warranty of 
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
GNU General Public License for more details. 

You should have received a copy of the GNU General Public License 
along with this program. If not, see <http://www.gnu.org/licenses/>. 

**************************************************************************/ 

class RegenerateThumbnails { 
    var $menu_id; 

    // Plugin initialization 
    function RegenerateThumbnails() { 
     // Load up the localization file if we're using WordPress in a different language 
     // Place it in this plugin's "localization" folder and name it "regenerate-thumbnails-[value in wp-config].mo" 
     load_plugin_textdomain('regenerate-thumbnails', false, '/regenerate-thumbnails/localization'); 

     add_action('admin_menu',        array(&$this, 'add_admin_menu')); 
     add_action('admin_enqueue_scripts',     array(&$this, 'admin_enqueues')); 
     add_action('wp_ajax_regeneratethumbnail',    array(&$this, 'ajax_process_image')); 
     add_filter('media_row_actions',      array(&$this, 'add_media_row_action'), 10, 2); 
     //add_filter('bulk_actions-upload',      array(&$this, 'add_bulk_actions'), 99); // A last minute change to 3.1 makes this no longer work 
     add_action('admin_head-upload.php',     array(&$this, 'add_bulk_actions_via_javascript')); 
     add_action('admin_action_bulk_regenerate_thumbnails', array(&$this, 'bulk_action_handler')); // Top drowndown 
     add_action('admin_action_-1',       array(&$this, 'bulk_action_handler')); // Bottom dropdown (assumes top dropdown = default value) 

     // Allow people to change what capability is required to use this plugin 
     $this->capability = apply_filters('regenerate_thumbs_cap', 'manage_options'); 
    } 


    // Register the management page 
    function add_admin_menu() { 
     $this->menu_id = add_management_page(__('Regenerate Thumbnails', 'regenerate-thumbnails'), __('Regen. Thumbnails', 'regenerate-thumbnails'), $this->capability, 'regenerate-thumbnails', array(&$this, 'regenerate_interface')); 
    } 


    // Enqueue the needed Javascript and CSS 
    function admin_enqueues($hook_suffix) { 
     if ($hook_suffix != $this->menu_id) 
      return; 

     // WordPress 3.1 vs older version compatibility 
     if (wp_script_is('jquery-ui-widget', 'registered')) 
      wp_enqueue_script('jquery-ui-progressbar', plugins_url('jquery-ui/jquery.ui.progressbar.min.js', __FILE__), array('jquery-ui-core', 'jquery-ui-widget'), '1.8.6'); 
     else 
      wp_enqueue_script('jquery-ui-progressbar', plugins_url('jquery-ui/jquery.ui.progressbar.min.1.7.2.js', __FILE__), array('jquery-ui-core'), '1.7.2'); 

     wp_enqueue_style('jquery-ui-regenthumbs', plugins_url('jquery-ui/redmond/jquery-ui-1.7.2.custom.css', __FILE__), array(), '1.7.2'); 
    } 


    // Add a "Regenerate Thumbnails" link to the media row actions 
    function add_media_row_action($actions, $post) { 
     if ('image/' != substr($post->post_mime_type, 0, 6) || ! current_user_can($this->capability)) 
      return $actions; 

     $url = wp_nonce_url(admin_url('tools.php?page=regenerate-thumbnails&goback=1&ids=' . $post->ID), 'regenerate-thumbnails'); 
     $actions['regenerate_thumbnails'] = '<a href="' . esc_url($url) . '" title="' . esc_attr(__("Regenerate the thumbnails for this single image", 'regenerate-thumbnails')) . '">' . __('Regenerate Thumbnails', 'regenerate-thumbnails') . '</a>'; 

     return $actions; 
    } 


    // Add "Regenerate Thumbnails" to the Bulk Actions media dropdown 
    function add_bulk_actions($actions) { 
     $delete = false; 
     if (! empty($actions['delete'])) { 
      $delete = $actions['delete']; 
      unset($actions['delete']); 
     } 

     $actions['bulk_regenerate_thumbnails'] = __('Regenerate Thumbnails', 'regenerate-thumbnails'); 

     if ($delete) 
      $actions['delete'] = $delete; 

     return $actions; 
    } 


    // Add new items to the Bulk Actions using Javascript 
    // A last minute change to the "bulk_actions-xxxxx" filter in 3.1 made it not possible to add items using that 
    function add_bulk_actions_via_javascript() { 
     if (! current_user_can($this->capability)) 
      return; 
?> 
     <script type="text/javascript"> 
      jQuery(document).ready(function($){ 
       $('select[name^="action"] option:last-child').before('<option value="bulk_regenerate_thumbnails"><?php echo esc_attr(__('Regenerate Thumbnails', 'regenerate-thumbnails')); ?></option>'); 
      }); 
     </script> 
<?php 
    } 


    // Handles the bulk actions POST 
    function bulk_action_handler() { 
     if (empty($_REQUEST['action']) || ('bulk_regenerate_thumbnails' != $_REQUEST['action'] && 'bulk_regenerate_thumbnails' != $_REQUEST['action2'])) 
      return; 

     if (empty($_REQUEST['media']) || ! is_array($_REQUEST['media'])) 
      return; 

     check_admin_referer('bulk-media'); 

     $ids = implode(',', array_map('intval', $_REQUEST['media'])); 

     // Can't use wp_nonce_url() as it escapes HTML entities 
     wp_redirect(add_query_arg('_wpnonce', wp_create_nonce('regenerate-thumbnails'), admin_url('tools.php?page=regenerate-thumbnails&goback=1&ids=' . $ids))); 
     exit(); 
    } 


    // The user interface plus thumbnail regenerator 
    function regenerate_interface() { 
     global $wpdb; 

     ?> 

<div id="message" class="updated fade" style="display:none"></div> 

<div class="wrap regenthumbs"> 
    <h2><?php _e('Regenerate Thumbnails', 'regenerate-thumbnails'); ?></h2> 

<?php 

     // If the button was clicked 
     if (! empty($_POST['regenerate-thumbnails']) || ! empty($_REQUEST['ids'])) { 
      // Capability check 
      if (! current_user_can($this->capability)) 
       wp_die(__('Cheatin&#8217; uh?')); 

      // Form nonce check 
      check_admin_referer('regenerate-thumbnails'); 

      // Create the list of image IDs 
      if (! empty($_REQUEST['ids'])) { 
       $images = array_map('intval', explode(',', trim($_REQUEST['ids'], ','))); 
       $ids = implode(',', $images); 
      } else { 
       // Directly querying the database is normally frowned upon, but all 
       // of the API functions will return the full post objects which will 
       // suck up lots of memory. This is best, just not as future proof. 
       if (! $images = $wpdb->get_results("SELECT ID FROM $wpdb->posts WHERE post_type = 'attachment' AND post_mime_type LIKE 'image/%' ORDER BY ID DESC")) { 
        echo ' <p>' . sprintf(__("Unable to find any images. Are you sure <a href='%s'>some exist</a>?", 'regenerate-thumbnails'), admin_url('upload.php?post_mime_type=image')) . "</p></div>"; 
        return; 
       } 

       // Generate the list of IDs 
       $ids = array(); 
       foreach ($images as $image) 
        $ids[] = $image->ID; 
       $ids = implode(',', $ids); 
      } 

      echo ' <p>' . __("Please be patient while the thumbnails are regenerated. This can take a while if your server is slow (inexpensive hosting) or if you have many images. Do not navigate away from this page until this script is done or the thumbnails will not be resized. You will be notified via this page when the regenerating is completed.", 'regenerate-thumbnails') . '</p>'; 

      $count = count($images); 

      $text_goback = (! empty($_GET['goback'])) ? sprintf(__('To go back to the previous page, <a href="%s">click here</a>.', 'regenerate-thumbnails'), 'javascript:history.go(-1)') : ''; 
      $text_failures = sprintf(__('All done! %1$s image(s) were successfully resized in %2$s seconds and there were %3$s failure(s). To try regenerating the failed images again, <a href="%4$s">click here</a>. %5$s', 'regenerate-thumbnails'), "' + rt_successes + '", "' + rt_totaltime + '", "' + rt_errors + '", esc_url(wp_nonce_url(admin_url('tools.php?page=regenerate-thumbnails&goback=1'), 'regenerate-thumbnails') . '&ids=') . "' + rt_failedlist + '", $text_goback); 
      $text_nofailures = sprintf(__('All done! %1$s image(s) were successfully resized in %2$s seconds and there were 0 failures. %3$s', 'regenerate-thumbnails'), "' + rt_successes + '", "' + rt_totaltime + '", $text_goback); 
?> 


    <noscript><p><em><?php _e('You must enable Javascript in order to proceed!', 'regenerate-thumbnails') ?></em></p></noscript> 

    <div id="regenthumbs-bar" style="position:relative;height:25px;"> 
     <div id="regenthumbs-bar-percent" style="position:absolute;left:50%;top:50%;width:300px;margin-left:-150px;height:25px;margin-top:-9px;font-weight:bold;text-align:center;"></div> 
    </div> 

    <p><input type="button" class="button hide-if-no-js" name="regenthumbs-stop" id="regenthumbs-stop" value="<?php _e('Abort Resizing Images', 'regenerate-thumbnails') ?>" /></p> 

    <h3 class="title"><?php _e('Debugging Information', 'regenerate-thumbnails') ?></h3> 

    <p> 
     <?php printf(__('Total Images: %s', 'regenerate-thumbnails'), $count); ?><br /> 
     <?php printf(__('Images Resized: %s', 'regenerate-thumbnails'), '<span id="regenthumbs-debug-successcount">0</span>'); ?><br /> 
     <?php printf(__('Resize Failures: %s', 'regenerate-thumbnails'), '<span id="regenthumbs-debug-failurecount">0</span>'); ?> 
    </p> 

    <ol id="regenthumbs-debuglist"> 
     <li style="display:none"></li> 
    </ol> 

    <script type="text/javascript"> 
    // <![CDATA[ 
     jQuery(document).ready(function($){ 
      var i; 
      var rt_images = [<?php echo $ids; ?>]; 
      var rt_total = rt_images.length; 
      var rt_count = 1; 
      var rt_percent = 0; 
      var rt_successes = 0; 
      var rt_errors = 0; 
      var rt_failedlist = ''; 
      var rt_resulttext = ''; 
      var rt_timestart = new Date().getTime(); 
      var rt_timeend = 0; 
      var rt_totaltime = 0; 
      var rt_continue = true; 

      // Create the progress bar 
      $("#regenthumbs-bar").progressbar(); 
      $("#regenthumbs-bar-percent").html("0%"); 

      // Stop button 
      $("#regenthumbs-stop").click(function() { 
       rt_continue = false; 
       $('#regenthumbs-stop').val("<?php echo $this->esc_quotes(__('Stopping...', 'regenerate-thumbnails')); ?>"); 
      }); 

      // Clear out the empty list element that's there for HTML validation purposes 
      $("#regenthumbs-debuglist li").remove(); 

      // Called after each resize. Updates debug information and the progress bar. 
      function RegenThumbsUpdateStatus(id, success, response) { 
       $("#regenthumbs-bar").progressbar("value", (rt_count/rt_total) * 100); 
       $("#regenthumbs-bar-percent").html(Math.round((rt_count/rt_total) * 1000)/10 + "%"); 
       rt_count = rt_count + 1; 

       if (success) { 
        rt_successes = rt_successes + 1; 
        $("#regenthumbs-debug-successcount").html(rt_successes); 
        $("#regenthumbs-debuglist").append("<li>" + response.success + "</li>"); 
       } 
       else { 
        rt_errors = rt_errors + 1; 
        rt_failedlist = rt_failedlist + ',' + id; 
        $("#regenthumbs-debug-failurecount").html(rt_errors); 
        $("#regenthumbs-debuglist").append("<li>" + response.error + "</li>"); 
       } 
      } 

      // Called when all images have been processed. Shows the results and cleans up. 
      function RegenThumbsFinishUp() { 
       rt_timeend = new Date().getTime(); 
       rt_totaltime = Math.round((rt_timeend - rt_timestart)/1000); 

       $('#regenthumbs-stop').hide(); 

       if (rt_errors > 0) { 
        rt_resulttext = '<?php echo $text_failures; ?>'; 
       } else { 
        rt_resulttext = '<?php echo $text_nofailures; ?>'; 
       } 

       $("#message").html("<p><strong>" + rt_resulttext + "</strong></p>"); 
       $("#message").show(); 
      } 

      // Regenerate a specified image via AJAX 
      function RegenThumbs(id) { 
       $.ajax({ 
        type: 'POST', 
        url: ajaxurl, 
        data: { action: "regeneratethumbnail", id: id }, 
        success: function(response) { 
         if (response.success) { 
          RegenThumbsUpdateStatus(id, true, response); 
         } 
         else { 
          RegenThumbsUpdateStatus(id, false, response); 
         } 

         if (rt_images.length && rt_continue) { 
          RegenThumbs(rt_images.shift()); 
         } 
         else { 
          RegenThumbsFinishUp(); 
         } 
        }, 
        error: function(response) { 
         RegenThumbsUpdateStatus(id, false, response); 

         if (rt_images.length && rt_continue) { 
          RegenThumbs(rt_images.shift()); 
         } 
         else { 
          RegenThumbsFinishUp(); 
         } 
        } 
       }); 
      } 

      RegenThumbs(rt_images.shift()); 
     }); 
    // ]]> 
    </script> 
<?php 
     } 

     // No button click? Display the form. 
     else { 
?> 
    <form method="post" action=""> 
<?php wp_nonce_field('regenerate-thumbnails') ?> 

    <p><?php printf(__("Use this tool to regenerate thumbnails for all images that you have uploaded to your blog. This is useful if you've changed any of the thumbnail dimensions on the <a href='%s'>media settings page</a>. Old thumbnails will be kept to avoid any broken images due to hard-coded URLs.", 'regenerate-thumbnails'), admin_url('options-media.php')); ?></p> 

    <p><?php printf(__("You can regenerate specific images (rather than all images) from the <a href='%s'>Media</a> page. Hover over an image's row and click the link to resize just that one image or use the checkboxes and the &quot;Bulk Actions&quot; dropdown to resize multiple images (WordPress 3.1+ only).", 'regenerate-thumbnails '), admin_url('upload.php')); ?></p> 

    <p><?php _e("Thumbnail regeneration is not reversible, but you can just change your thumbnail dimensions back to the old values and click the button again if you don't like the results.", 'regenerate-thumbnails'); ?></p> 

    <p><?php _e('To begin, just press the button below.', 'regenerate-thumbnails '); ?></p> 

    <p><input type="submit" class="button hide-if-no-js" name="regenerate-thumbnails" id="regenerate-thumbnails" value="<?php _e('Regenerate All Thumbnails', 'regenerate-thumbnails') ?>" /></p> 

    <noscript><p><em><?php _e('You must enable Javascript in order to proceed!', 'regenerate-thumbnails') ?></em></p></noscript> 

    </form> 
<?php 
     } // End if button 
?> 
</div> 

<?php 
    } 


    // Process a single image ID (this is an AJAX handler) 
    function ajax_process_image() { 
     @error_reporting(0); // Don't break the JSON result 

     header('Content-type: application/json'); 

     $id = (int) $_REQUEST['id']; 
     $image = get_post($id); 

     if (! $image || 'attachment' != $image->post_type || 'image/' != substr($image->post_mime_type, 0, 6)) 
      die(json_encode(array('error' => sprintf(__('Failed resize: %s is an invalid image ID.', 'regenerate-thumbnails'), esc_html($_REQUEST['id']))))); 

     if (! current_user_can($this->capability)) 
      $this->die_json_error_msg($image->ID, __("Your user account doesn't have permission to resize images", 'regenerate-thumbnails')); 

     $fullsizepath = get_attached_file($image->ID); 

     if (false === $fullsizepath || ! file_exists($fullsizepath)) 
      $this->die_json_error_msg($image->ID, sprintf(__('The originally uploaded image file cannot be found at %s', 'regenerate-thumbnails'), '<code>' . esc_html($fullsizepath) . '</code>')); 

     @set_time_limit(900); // 5 minutes per image should be PLENTY 

     $metadata = wp_generate_attachment_metadata($image->ID, $fullsizepath); 

     if (is_wp_error($metadata)) 
      $this->die_json_error_msg($image->ID, $metadata->get_error_message()); 
     if (empty($metadata)) 
      $this->die_json_error_msg($image->ID, __('Unknown failure reason.', 'regenerate-thumbnails')); 

     // If this fails, then it just means that nothing was changed (old value == new value) 
     wp_update_attachment_metadata($image->ID, $metadata); 

     die(json_encode(array('success' => sprintf(__('&quot;%1$s&quot; (ID %2$s) was successfully resized in %3$s seconds.', 'regenerate-thumbnails'), esc_html(get_the_title($image->ID)), $image->ID, timer_stop())))); 
    } 


    // Helper to make a JSON error message 
    function die_json_error_msg($id, $message) { 
     die(json_encode(array('error' => sprintf(__('&quot;%1$s&quot; (ID %2$s) failed to resize. The error message was: %3$s', 'regenerate-thumbnails'), esc_html(get_the_title($id)), $id, $message)))); 
    } 


    // Helper function to escape quotes in strings for use in Javascript 
    function esc_quotes($string) { 
     return str_replace('"', '\"', $string); 
    } 
} 

// Start up this plugin 
add_action('init', 'RegenerateThumbnails'); 
function RegenerateThumbnails() { 
    global $RegenerateThumbnails; 
    $RegenerateThumbnails = new RegenerateThumbnails(); 
} 

// sharpen uploaded images 
function ajx_sharpen_resized_files($resized_file) { 

    $image = wp_load_image($resized_file); 
    if (!is_resource($image)) 
     return new WP_Error('error_loading_image', $image, $file); 

    $size = @getimagesize($resized_file); 
    if (!$size) 
     return new WP_Error('invalid_image', __('Could not read image size'), $file); 
    list($orig_w, $orig_h, $orig_type) = $size; 

    switch ($orig_type) { 
     case IMAGETYPE_JPEG: 
      $matrix = array(
       array(apply_filters('sharpen_resized_corner',-1.2), apply_filters('sharpen_resized_side',-1), apply_filters('sharpen_resized_corner',-1.2)), 
       array(apply_filters('sharpen_resized_side',-1), apply_filters('sharpen_resized_center',20), apply_filters('sharpen_resized_side',-1)), 
       array(apply_filters('sharpen_resized_corner',-1.2), apply_filters('sharpen_resized_side',-1), apply_filters('sharpen_resized_corner',-1.2)), 
      ); 

      $divisor = array_sum(array_map('array_sum', $matrix)); 
      $offset = 0; 
      imageconvolution($image, $matrix, $divisor, $offset); 
      imagejpeg($image, $resized_file,apply_filters('jpeg_quality', 100, 'edit_image')); 
      break; 
     case IMAGETYPE_PNG: 
      return $resized_file; 
     case IMAGETYPE_GIF: 
      return $resized_file; 
    } 

    // we don't need images in memory anymore 
    imagedestroy($image); 

    return $resized_file; 
} 

add_filter('image_make_intermediate_size', 'ajx_sharpen_resized_files', 900); 

?> 

Answer 3

这里是解决办法，如果你的WordPress后缩略图模糊，去你的主题CSS，获取代码：

.secondary-posts .post-thumbnail 
width: 100%; 
background-color: #666; 
height: 150px; 
padding: 0; 
box-shadow: 0 0px 5px #888; 
background-repeat: no-repeat; 
background-position:center; 
background-size: 150px auto; 

（CHANGE此背景大小，以

我已经用了我们的网站和它的作品，缩略图现在尖锐的缩图箱尺寸（例如150像素），这里是结果 ：http://kresnatourjogja.com/category/jogjakarta-temple/