在用于增益补偿的回调函数中，将hi_stitching_gain_param.calulate_gain_callback.hist_config字段转换为hi_stitching_histogram_param结构体，可参见转换示例代码。

typedef struct {
    hi_u32 pic_index;
    hi_u32 overlap_pic_index;
    hi_vpc_histogram_config histogram_info;
} hi_stitching_histogram_param;

成员名称	描述
pic_index	输入图片编号。
overlap_pic_index	当直方图统计类型hi_stitching_histogram_type为OVERLAP_HISTOGRAM 时，overlap_pic_index参数表示与输入图片有重叠区域的图片的编号。
histogram_info	直方图统计结果。

hi_stitching_histogram_param *hisData = (hi_stitching_histogram_param *)hist_config;