Mizuho Ogino

<p>By uploading a PDF attachment, this plugin convert the cover page to jpeg and attach it as a post thumbnail file. It also allows displaying a thumbnail icon and inserting PDF link with a cover image into the editor.</p>
<h4>Available only for WordPress 4.0+, also only on the server which  ImageMagick and GhostScript are installed.</h4>
<p>This plugin hooks to the media editor and generates the first page image of PDF by using ImageMagick with GhostScript. It requires no setup, just activate the plugin via the admin install page. Allow to set a PDF as an image.</p>
<h4>How it works</h4>
<p>This Plugin replaces and extends the following features.</p>
<ul>
<li>Generate cover image of PDF by using ImageMagick. Generated Image has different size variations and is attached to PDF.</li>
<li>Register Generated Image as Featured Image (post-thumbnail) of PDF.</li>
<li>Display Generated Image as icon instead of Mime-type Icon in Admin Page.</li>
<li>Hide Generated Image file itself in Media Library. (v1.2 or later)</li>
<li>Replace link text with JPG when inserting PDF to Text Editor.</li>
<li>Delete Generated Image when deleting PDF from Media Library.</li>
<li>Allow to manage and output Generated Image and PDF on manually in template file. (see Other Notes.)</li>
<li>Allow to set PDF as Featured Image and to use functions in the same way as image file. (v1.2 or later, see Other Notes.)</li>
<li>Allow to control maximum size of Generated Image and other default settings in Plugin Page. (v1.3.4 or later)</li>
</ul>
<h4>Generated Items</h4>
<p>A generated image file is registered as post children of a PDF file and it has different size variations. Files build a tree like below.</p>
<ul>
<li>my-file.pdf (Your PDF)
<ul>
<li>my-file-pdf.jpg (Generated Cover Image of Your PDF)
<ul>
<li>my-file-pdf-1024×768.jpg (Large Size)</li>
<li>my-file-pdf-300×225.jpg (Medium Size)</li>
<li>my-file-pdf-150×150.jpg (Thumbnail size)</li>
<li>…(And Your Custom File Sizes)</li>
</ul>
</li>
</ul>
</li>
</ul>
<h4>Insert HTML into the editor</h4>
<p>Select a PDF file in the Media Uploader and insert it into the the editor. An output HTML is automatically rewritten like below.</p>
<pre><code><a class="link-to-pdf" title="dummy-pdf" href="http://exmaple.com/wp-content/uploads/2015/01/dummy-pdf.pdf" target="_blank"><img width="227" height="320" class="size-medium wp-image-9999 thumb-of-pdf" src="http://exmaple.com/wp-content/uploads/2015/01/dummy-pdf-pdf-227x320.jpg" alt="thumbnail-of-dummy-pdf" /></a>
</code></pre>
<p>*If you are using a document viewer plugin (like GDE) and want insert html which is made by it, select “Default (Title)” of “media” selector.</p>
<h4>Get thumbnail in template file</h4>
<p>A generated image ID is stored in [‘_thumbnail_id’] custom field of a PDF attachment post. An image ID is exportable by using get_post_thumbnail_id($your_pdf_id) or get_post_meta($your_pdf_id, ‘_thumbnail_id’, true) functions in a template file.</p>
<pre><code>$pdf_id = 'your PDF file ID';
if ( $thumbnail_id = get_post_thumbnail_id( $pdf_id ) ) {
echo '<a class="pdf-link image-link" href="'.wp_get_attachment_url( $pdf_id ).'" title="'.esc_attr( get_the_title( $pdf_id ) ).'" target="_blank">'.wp_get_attachment_image ( $thumbnail_id, 'medium' ).'</a>';
}
</code></pre>
<p>Or more simply, you can call images and link to PDF files by wp_get_attachment_image($your_pdf_id, $size) and wp_get_attachment_link($your_pdf_id, $size) functions. (v1.2 or later) *If the plugin is deactivated, this function just will return empty.</p>
<pre><code>$pdf_id = 'your PDF file ID';
echo wp_get_attachment_image ( $pdf_id, 'medium' );
echo wp_get_attachment_link ( $pdf_id, 'medium' );
</code></pre>
<p>If you call all PDFs that are attached to the post. You can get them by get_posts function.</p>
<p>Examples.<br />
Dynamically get PDFs that are attached to the post.</p>
<pre><code><?php
$pdfs = get_posts( 'posts_per_page=-1&post_type=attachment&post_mime_type=application/pdf&post_parent='.$post->ID );
if( $pdfs ): foreach( $pdfs as $pdf ):
  $thumbnail_id = get_post_thumbnail_id( $pdf->ID );
  if( $thumbnail_id ):
    echo '<li>';
    echo '<a href="'wp_get_attachment_url( $pdf->ID )'" class="link-to-pdf">';
    echo wp_get_attachment_image ( $thumbnail_id, 'medium' );
    echo '</a>';
    echo '</li>';
  endif;
endforeach; endif;
?>
</code></pre>
<h4>Set PDF thumbnail as Featured Image</h4>
<p>The plugin support you to set PDF as Featured Image. (v1.2 or later)<br />
Strictly explaining, when you set a PDF as Featured Image, the plugin automatically set the thumbnail which is registered with this PDF.<br />
You can call thumbnail by using get_the_post_thumbnail function.</p>
<pre><code>echo get_the_post_thumbnail ( $post->ID, 'medium' );
</code></pre>
<p>May you want pdf file from the post thumbnail.</p>
<pre><code>$thumb_id = get_post_thumbnail_id ( $post->ID );
$pdf_id = get_post( $thumb_id )->post_parent;
if ( $pdf_id && get_post_mime_type ( $pdf_id ) === 'application/pdf' ){
  $pdf = get_post($pdf_id);
  echo '<a class="link-to-pdf" href="'.wp_get_attachment_url($pdf_id).'" title="'.esc_html($pdf->post_title).'" target="_blank">'.get_the_post_thumbnail().'</a>'."\n";
}
</code></pre>
<h4>Display attachment data with in caption</h4>
<p>The plugin allows you to insert [caption] short-code into the post content area as when insert an image. If you want to display attachment title, description, file type, file size and so on, use img_caption_shortcode filter in your functions.php.<br />
Here’s an example code…<br />
    function add_attachment_data_in_caption( $empty, $attr, $content ) {<br />
        $attr = shortcode_atts( array( ‘id’=>”, ‘align’=>’alignnone’, ‘width’=>”, ‘caption’=>” ), $attr );<br />
        if ( 1 > (int) $attr[‘width’] || empty( $attr[‘caption’] ) ) return ”;<br />
        if ( $attr[‘id’] ) {<br />
            $attr[‘id’] = ‘id=”‘ . esc_attr( $attr[‘id’] ) . ‘” ‘;<br />
            $attachment_id = explode(‘_’, $attr[‘id’]);<br />
            $attachment_id = $attachment_id[1];// get attachment id<br />
            if( get_post_mime_type ( $attachment_id ) === ‘application/pdf’ ){<br />
                $attachment = get_post( $attachment_id );<br />
                $bytes = filesize( get_attached_file( $attachment->ID ) );<br />
                if ($bytes >= 1073741824) $bytes = number_format($bytes / 1073741824, 2). ‘ GB’;<br />
                elseif ($bytes >= 1048576) $bytes = number_format($bytes / 1048576, 2). ‘ MB’;<br />
                elseif ($bytes >= 1024) $bytes = number_format($bytes / 1024, 2). ‘ KB’;<br />
                elseif ($bytes > 1) $bytes = $bytes. ‘ bytes’;<br />
                elseif ($bytes == 1) $bytes = $bytes. ‘ byte’;<br />
                else $bytes = ‘0 bytes’;<br />
                $attr[‘caption’] =<br />
                  ‘title : ‘ .$attachment->post_title. ‘<br />‘ . // title<br />
                  ‘caption : ‘ .$attr[‘caption’]. ‘<br />‘ .// caption<br />
                  ‘size : ‘ .$bytes. ‘<br />‘ . // file size<br />
                  ‘filetype : ‘ .get_post_mime_type ( $attachment_id ). ‘<br />‘ . // file type<br />
                  ‘description : ‘ .$attachment->post_content. ‘<br />‘; // description<br />
            }<br />
        }</p>
<pre><code>    return 
      '<div ' .$attr['id']. 'class="wp-caption ' .esc_attr( $attr['align'] ). '" style="max-width: ' .( 10 + (int) $attr['width'] ). 'px;">' .
      do_shortcode( $content ). '<p class="wp-caption-text">' .$attr['caption']. '</p>' .
      '</div>';
}
add_filter('img_caption_shortcode', 'add_attachment_data_in_caption', 10, 3);
</code></pre>
<h4>Generate thumbnails of all PDFs in the media library</h4>
<p>You can generate thumbnails of any already-uploaded PDFs.<br />
Activate the plugin and Click “Generate Thumbnails Now” link in “settings”. (v1.3.3 or later)</p>
<h4>Change attachment link attributes</h4>
<pre><code>function pigen_filter_attachment_link ( $html, $attach_id, $attach_url, $attach_output ){
  $attach_title = get_the_title( $attach_id );
  $html = '<a class="link-to-pdf" href="'.$attach_url.'" rel="attachment wp-att-' .esc_attr($attach_id). '" title="'.esc_attr( $attach_title ).'" target="_blank">' .$attach_output. '</a>';
  return $html;
};
add_filter( 'pigen_filter_attachment_link', 'pigen_filter_attachment_link', 10, 4 );
</code></pre>
<h4>Change thumbnail attributes</h4>
<pre><code>function pigen_filter_attachment_output ( $attach_output, $thumbnail_id, $thumbnail, $size, $align ){
  $attach_output =  '<img src="'. $thumbnail[0] .'" alt="'.get_post_meta( $thumbnail_id, '_wp_attachment_image_alt', true ).'" width="'. $thumbnail[1] .'" height="'. $thumbnail[2] .'" class="'.( $align ? 'align' .$align. ' ' : '' ). 'size-' .esc_attr( $size ). ' wp-image-'.$thumbnail_id.'" />';
  return $attach_output;
};
add_filter( 'pigen_filter_attachment_output', 'pigen_filter_attachment_output', 10, 5 );
</code></pre>
<h4>Modify imageMagick’s Settings</h4>
<p>Filters allow you to add your own modify imageMagick’s behaviour by hooking.</p>
<p>Sample usage for imageMagick user.</p>
<pre><code>function pigen_filter_convert_file_basename( $file_basename ){
  $file_basename = str_replace( '.jpg', '.png', $file_basename );
  return $file_basename;
};
add_filter( 'pigen_filter_convert_file_basename', 'pigen_filter_convert_file_basename' );

function pigen_filter_convert_imageMagick( $imageMagick, $before_name, $after_name, $max_width, $max_height ){
  $imageMagick = "convert -density 150 -quality 80 -background black -flatten {$max_width}x{$max_height} {$before_name} {$after_name}";
  return $imageMagick;
};
add_filter( 'pigen_filter_convert_imageMagick', 'pigen_filter_convert_imageMagick', 10, 5 );
</code></pre>
<p>Sample usage for imagick extension user.</p>
<pre><code>function pigen_filter_convert_file_basename( $file_basename ){
  $file_basename = str_replace( '.jpg', '.png', $file_basename );
  return $file_basename;
};
add_filter( 'pigen_filter_convert_file_basename', 'pigen_filter_convert_file_basename' );

function pigen_filter_convert_imagick( $imagick ){
  $imagick->setImageBackgroundColor( 'black' );
  $imagick->setCompressionQuality( 80 );
  $imagick->setImageFormat( 'png' );
return $imagick;
};
add_filter( 'pigen_filter_convert_imagick', 'pigen_filter_convert_imagick' );
</code></pre>
<h4>Automatically save image/PDF as featured image</h4>
<p>Automatically set PDF thumbnail as featured image.</p>
<pre><code>function save_pdf_thumb_as_featuredimage ( $post_id ) { 
    if ( wp_is_post_revision( $post_id ) ) return; 
    if ( get_post_type( $post_id ) !== 'post' ) return; // set your post type
    if ( get_post_meta( $post_id, '_thumbnail_id', true ) ) return; // post already has featured image
    $attaches = get_posts ( 'post_parent='.$post_id.'&numberposts=-1&post_type=attachment&post_mime_type=application/pdf&orderby=menu_order&order=ASC' );
    if ( $attaches ): foreach( $attaches as $attach ):
        if ( $thumb_id = get_post_meta( $attach->ID, '_thumbnail_id', true ) ){ // if pdf has thumbnail
            update_post_meta( $post_id, '_thumbnail_id', $thumb_id );
            break;
        }
    endforeach; endif;
}
add_action( 'save_post', 'save_pdf_thumb_as_featuredimage' );
</code></pre>
<p>Automatically set first image/PDF as featured image.</p>
<pre><code>function save_thumbnail_as_featuredimage ( $post_id ) { 
    if ( wp_is_post_revision( $post_id ) ) return;
    if ( get_post_type( $post_id ) !== 'post' ) return; // set your post type
    if ( get_post_meta( $post_id, '_thumbnail_id', true ) ) return; // post already has featured image
    $args = array(
        'post_parent' => $post_id,
        'post_type' => 'attachment',
        'numberposts' => -1,
        'post_status' => null,
        'orderby' => 'menu_order date',
        'order' => 'ASC ASC'
    );
    $attaches = get_posts($args);
    if ( $attaches ): foreach( $attaches as $attach ):
        if ( $attach->post_mime_type == 'application/pdf' ){
            if ( $thumb_id = get_post_meta( $attach->ID, '_thumbnail_id', true ) ){ // if pdf has thumbnail
                update_post_meta( $post_id, '_thumbnail_id', $thumb_id );
                break;
            }
        } elseif ( preg_match("/^image\//", $attach->post_mime_type ) ) {
            update_post_meta( $post_id, '_thumbnail_id', $attach->ID );
            break;
        }
    endforeach; endif;
}
add_action( 'save_post', 'save_thumbnail_as_featuredimage' );
</code></pre>


PDF Image Generator

Also ties in really nicely with the media uploader, the image is set as the 'icon' field of the attachment, as one would want. PS The feature for generating images for existing pdfs is at the bottom of the settings - scroll down to see (unlike me the first time)!

Super stuff. Works perfectly.

Very impressed with how quick and easy it was to get up and running with the generated pdf views.

Great Little Plugin

Generate automatically cover image of PDF by using ImageMagick. Allow user to insert PDF link with thumbnail into editor and set as Featured Image.

rainafarai

<p><strong>Raina Image Compression</strong> is a powerful WordPress plugin that automatically optimizes images during upload while giving full control over compression, output format, and metadata. It is designed for site owners who want fast-loading pages, SEO-friendly images, and a reliable system that prevents users from uploading huge, unoptimized files.<br />
The plugin works with the built-in <strong>GD library</strong> and intelligently handles <strong>JPG, PNG, and WebP</strong> formats. It can also <strong>convert non-transparent PNGs to JPG</strong>, achieving better compression without visible quality loss.</p>
<p>Ideal for multi-author sites or blogs managed by non-technical users, Raina Image Compression operates automatically in the background, optionally sends Telegram notifications, and keeps your image sizes under control.</p>
<h4>Key Features</h4>
<p><strong>Smart Image Optimization</strong><br />
– Automatically compresses JPG and PNG images.<br />
– Converts non-transparent PNGs to JPG for better performance.</p>
<p><strong>Output Mode Selection (4 available modes)</strong><br />
Choose how your images are generated after upload:<br />
– 1. JPG/PNG ONLY Compresses only JPG and PNG files.<br />
– 2. WEBP ONLY  Creates only a WebP version.<br />
– 3. JPG/PNG PRIMARY + WEBP COPY  Keeps the original JPG/PNG as the main file and creates a WebP copy in the media library.<br />
– 4. WEBP PRIMARY + JPG/PNG COPY Sets the WebP image as the primary file while retaining a JPG/PNG copy for compatibility.</p>
<p><strong>Maximum Width Control</strong><br />
Set a maximum pixel width for uploaded images to automatically resize large photos from cameras or smartphones.</p>
<p><strong>Smart JPG Size Reduction (by KB Limit)</strong><br />
When enabled, the plugin will try to reduce a JPG’s file size to stay below a specific kilobyte (KB) limit by dynamically lowering the quality level until the target is reached. ( ONLY FOR JPG and No transparent PNG )</p>
<p><strong>Compress Only from Post Editor (Optional)</strong><br />
Option to limit compression to images uploaded directly from the WordPress post editor, excluding other uploads from plugins or themes or media library.</p>
<p><strong>Post Type Filter</strong><br />
Added a new option to select which post types the plugin should apply to. If none are selected, all post types will be processed.</p>
<p><strong>Keep Original File Copy</strong><br />
Option to create a full-size copy of the original uploaded image in the media library for backup or archival purposes.</p>
<p><strong>Disable WP Auto-Generated Thumbnails</strong><br />
Option to disable WP Auto-Generated Thumbnails. Save disk space by preventing WordPress from creating unnecessary image files.</p>
<p><strong>Automatic Metadata Filling</strong><br />
Automatically fills ALT, Description, and Caption (Excerpt) fields using the parent post information — ideal for improving SEO with no extra effort.</p>
<p><strong>Admin Bar Toggle</strong><br />
Easily enable or disable compression from the WordPress admin bar without entering the settings page, handy when you want to upload images related to the theme or the builder, basically content not associated with any post type.</p>
<p><strong>Telegram Notifications (Optional)</strong><br />
If the “Notifications for Telegram” plugin is installed, you will receive a message for each processed image containing:<br />
– File name<br />
– Format<br />
– Compression ratio</p>
<p><strong>Logging</strong><br />
Can Records all compression events to the WordPress debug log (<code>wp-content/debug.log</code>) for debugging or performance tracking.</p>
<p><strong>Lightweight & Compatible</strong><br />
– Works entirely on your server with no external API, CDN or remote requests.<br />
– Fully compatible with shared hosting environments.<br />
– No third-party dependencies.</p>
<h4>Ideal Use Cases</h4>
<ul>
<li>Websites managed by non-technical users who often upload large, unoptimized images.  </li>
<li>Site owners and developers who want full control over compression settings.  </li>
<li>Blogs or news sites that require consistent image optimization without external services.  </li>
</ul>
<h4>Summary</h4>
<p>Raina Image Compression was built to solve a common problem: users uploading excessively large images that slow down websites.<br />
It works quietly in the background, optimizing every image for size, speed, and SEO — so your site stays fast, clean, and professional.</p>
<h3>License</h3>
<p>This plugin 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 2 of the License, or (at your option) any later version.</p>


Raina Image Compression

Smart automatic image optimization and compression for faster WordPress sites.

PDF Image Generator vs Raina Image Compression