woocommerce Product Image Sizes

add_filter( 'woocommerce_get_image_size_gallery_thumbnail', 'cg_woocommerce_image_size_gallery_thumbnail', 99 );
function cg_woocommerce_image_size_gallery_thumbnail( $size ) {
    return array(
        'width'  => 800,
        'height' => 800,
        'crop'   => 1,
    );
}