自定义消息Image赋值、CompressedImage赋值

自定义消息中的有Image 、compressedImage类型怎么赋值

    sensor_msgs::ImagePtr msg = cv_bridge::CvImage(std_msgs::Header(),"bgr8",out_mat).toImageMsg(); 
    raw_image_data.raw_image=*msg;

    sensor_msgs::CompressedImagePtr img_bridge = cv_bridge::CvImage(std_msgs::Header(),"bgr8",out_mat).toCompressedImageMsg();
    raw_image_data.compressedImage =*img_bridge;