stbi使用opencv Mat buffer从内存加载

目前,我使用zxing(c++端口)扫描条形码,该端口使用stbi泳load从路径读取图像:

filePath = "..\\data\\qr_t2.bmp";
int width, height, channels;
unsigned char *bytes;
bytes = stbi_load(filePath.c_str(), &width, &height, &channels, 4);
std::unique_ptr<stbi_uc, void(*)(void*)> buffer(bytes/*stbi_load(filePath.c_str(), &width, &height, &channels, 4)*/, stbi_image_free);

但是我想用stbi_load_from_memory从内存读取图像,我的图像数据是使用opencv的Mat,我的代码如下:

typedef unsigned char BYTE;

Mat img_barcode = imread("..\\data\\qr_t2.bmp", 1);
int width = img_barcode.cols;
int height = img_barcode.rows;
BYTE *pImg;
int nFlag = img_barcode .channels() * 8;//bits of one pixel

int nBytes = width * height * nFlag / 8;//totoal bits of image
//if (pImg)
//  delete[] pImg;
pImg = new BYTE[nBytes];//unit of new is BYTE
memcpy(pImg, srcImg.data, nBytes);//

std::unique_ptr<stbi_uc, void(*)(void*)> buffer1(stbi_load_from_memory(pImg, 100*100*3, &width, &height, &channels, 3), stbi_image_free);

buffer1总是空的!有人能帮忙吗?

my test img Qr code