3399prox，rockx_image_draw_rect 报错

3399prox板子，安卓版本下，使用720P尺寸的 YUV_NV12 数据，进行人脸检测。

rockx_image_t picImage;

picImage.width = 1280;
picImage.height = 720;
picImage.is_prealloc_buf = 0;
picImage.original_ratio = 1;
picImage.data = (unsigned char *) pPicBuff; // 存放 YUV 数据的 char 数组
picImage.size = 1280*720*3/2;


使用 人脸识别，进行检索操作，大致流程如下：
E/cv::error(): OpenCV(3.4.1) Error: Assertion failed (cn <= 4) in void cv::scalarToRawData(const Scalar&, void*, int, int), file /build/master_pack-android/opencv/modules/core/src/array.cpp, line 3232
E/libc++abi: terminating with uncaught exception of type cv::Exception: OpenCV(3.4.1) /build/master_pack-android/opencv/modules/core/src/array.cpp:3232: error: (-215) cn <= 4 in function void cv::scalarToRawData(const Scalar&, void*, int, int)

请问如何处理啊?