// ────────────────────────────────────────────────────────────────────────
// OCR Labels Report + Clear Button
// ────────────────────────────────────────────────────────────────────────
add_action( 'admin_menu', function(){
    add_submenu_page(
        'edit.php?post_type=image',   // parent: Images CPT
        'OCR Labels',                 // page title
        'OCR Labels',                 // menu title
        'manage_options',             // capability
        'image-ocr-labels',           // menu slug
        'stoxo_render_ocr_report'     // callback
    );
}, 20 );

/**
 * Render the OCR report table, thumbnails, and a “Clear All” form.
 */
function stoxo_render_ocr_report() {
    // handle “Clear All” action
    if ( isset( $_POST['stoxo_clear_ocr'] ) && check_admin_referer( 'stoxo_clear_ocr_action', 'stoxo_clear_ocr_nonce' ) ) {
        global $wpdb;
        // delete all posts’ _ocr_labels meta
        delete_post_meta_by_key( '_ocr_labels' );
        echo '<div class="notice notice-success is-dismissible"><p>All OCR labels cleared.</p></div>';
    }

    // fetch only posts that have non-empty _ocr_labels
    $posts = get_posts( [
        'post_type'      => 'image',
        'posts_per_page' => -1,
        'meta_query'     => [
            [
                'key'     => '_ocr_labels',
                'compare' => 'EXISTS',
            ],
            [
                'key'     => '_ocr_labels',
                'value'   => '',
                'compare' => '!=',
            ],
        ],
    ] );

    echo '<div class="wrap">';
    echo '<h1>OCR Labels <span class="subtitle">(' . count( $posts ) . ' items)</span></h1>';

    // “Clear All” button
    echo '<form method="post" style="margin-bottom:1.5em;">';
    wp_nonce_field( 'stoxo_clear_ocr_action', 'stoxo_clear_ocr_nonce' );
    echo '<input type="submit" name="stoxo_clear_ocr" class="button button-secondary" value="Clear All OCR Labels" onclick="return confirm(\'Are you sure you want to remove all OCR labels?\');">';
    echo '</form>';

    echo '<table class="widefat fixed striped">';
    echo '<thead><tr>';
    echo '<th style="width:80px;">Thumb</th>';
    echo '<th style="width:60px;">ID</th>';
    echo '<th>Title</th>';
    echo '<th>OCR Text</th>';
    echo '<th style="width:100px;">Actions</th>';
    echo '</tr></thead>';
    echo '<tbody>';

    if ( empty( $posts ) ) {
        echo '<tr><td colspan="5" style="text-align:center;">No OCR labels found.</td></tr>';
    } else {
        foreach ( $posts as $p ) {
            $text = get_post_meta( $p->ID, '_ocr_labels', true );
            // get thumbnail HTML at 150×150
            $thumb = has_post_thumbnail( $p->ID )
                ? get_the_post_thumbnail( $p->ID, [150,150], ['style'=>'width:75px;height:75px;object-fit:cover;border:1px solid #ccc;'] )
                : '<div style="width:75px;height:75px;background:#f1f1f1;border:1px solid #ccc;line-height:75px;text-align:center;color:#999;">No<br>Thumb</div>';
            printf(
                '<tr>
                    <td>%1$s</td>
                    <td>%2$u</td>
                    <td><a href="%5$s">%3$s</a></td>
                    <td><pre style="white-space:pre-wrap; max-width:400px;">%4$s</pre></td>
                    <td>
                        <a class="button button-small" href="%5$s">Edit</a><br>
                        <a class="button button-small" onclick="return confirm(\'Trash this post?\');" href="%6$s">Trash</a>
                    </td>
                </tr>',
                $thumb,
                $p->ID,
                esc_html( get_the_title( $p->ID ) ),
                esc_html( $text ),
                esc_url( admin_url( 'post.php?post=' . $p->ID . '&action=edit' ) ),
                esc_url( get_delete_post_link( $p->ID ) )
            );
        }
    }

    echo '</tbody></table>';
    echo '</div>';
}
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /var/www/html/wp-content/mu-plugins/ocr-scan.php:1) in <b>/var/www/html/wp-includes/pluggable.php</b> on line <b>1450</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /var/www/html/wp-content/mu-plugins/ocr-scan.php:1) in <b>/var/www/html/wp-includes/pluggable.php</b> on line <b>1453</b><br />