Für die functions.php oder für das Plugin Code Snippets:

/* Automatically set the image Title, Alt-Text, Caption & Description upon upload
————————————————————————————–*/
add_action( ‚add_attachment‘, ‚my_set_image_meta_upon_image_upload‘ );
function my_set_image_meta_upon_image_upload( $post_ID ) {

// Check if uploaded file is an image, else do nothing

if ( wp_attachment_is_image( $post_ID ) ) {

$my_image_title = get_post( $post_ID )->post_title;

// Sanitize the title: remove hyphens, underscores & extra spaces:
$my_image_title = preg_replace( ‚%\s*[-_\s]+\s*%‘, ‚ ‚, $my_image_title );

// Sanitize the title: capitalize first letter of every word (other letters lower case):
$my_image_title = ucwords( strtolower( $my_image_title ) );

// Create an array with the image meta (Title, Caption, Description) to be updated
// Note: comment out the Excerpt/Caption or Content/Description lines if not needed
$my_image_meta = array(
‚ID‘ => $post_ID, // Specify the image (ID) to be updated
‚post_title‘ => $my_image_title, // Set image Title to sanitized title
// ‚post_excerpt‘ => $my_image_title, Set image Caption (Excerpt) to sanitized title
// ‚post_content‘ => $my_image_title, // Set image Description (Content) to sanitized title
);

// Set the image Alt-Text
update_post_meta( $post_ID, ‚_wp_attachment_image_alt‘, $my_image_title );

// Set the image meta (e.g. Title, Excerpt, Content)
wp_update_post( $my_image_meta );

}
}