KC custom image size support.php

//register field
array(
  'type'			=> 'text',
  'label'			=> __( 'Image Size', 'uniqlo' ),
  'name'			=> 'image_size',
  'value'			=> '570x290-crop',
  'description'   => __(' Set the image size: "full", "thumbnail", "medium", "large", "390x450-crop" or ex:500x250', 'uniqlo'),
),

// custom image size
$size_array = array('full', 'medium', 'large', 'thumbnail','570x290-crop');

$data_image = '';
if( in_array( $image_size, $size_array ) ){
  $data_image = wp_get_attachment_image( $image_id, $image_size);
}else{
  $img_full = wp_get_attachment_image_src( $image_id, 'full' )[0];
  $custom_img_url = kc_tools::createImageSize( $img_full, $image_size );
  $img_alt = get_post_meta( $image_id, '_wp_attachment_image_alt', true);

  $data_image = '<img src="'.$custom_img_url.'" alt="'.$img_alt.'" >';
}