Thêm đoạn dưới vào funtion.php
// Make sure featured images are enabled
add_theme_support( ‘post-thumbnails’ );
// Add featured image sizes
add_image_size( ‘featured-large’, 640, 294, true ); // width, height, crop
add_image_size( ‘featured-small’, 320, 147, true );
// Add other useful image sizes for use through Add Media modal
add_image_size( ‘medium-akasa’, 640, 480 );
// Register the three useful image sizes for use in Add Media modal
add_filter( ‘image_size_names_choose’, ‘wpshout_custom_sizes’ );
function wpshout_custom_sizes( $sizes ) {
return array_merge( $sizes, array(
‘medium-akasa’ => __( ‘Featured Akasa’ ),
) );
}
Dùng plugin này để cắt lại toàn bộ ảnh theo kích thước mới
Tham khảo: https://wpshout.com/wordpress-custom-image-sizes/