写一个 c++的函数 cv::Mat 转换为 ncnn的Mat格式
时间: 2024-09-14 19:09:31 浏览: 73
ncnn-mtcnn:这是一个基于ncnn的mtcnn项目
在C++中,将OpenCV (`cv::Mat`) 转换为 NCNN (`ncnn::Mat`) 格式,首先需要确保两者的数据类型兼容。一般来说,如果你的OpenCV `cv::Mat` 是基于BGR(蓝色、绿色、红色)颜色空间的图像,并且你想保持这个顺序在NCNN中,你可以这样做:
```cpp
#include "opencv2/opencv.hpp"
#include "ncnn.h"
// OpenCV Mat to NCNN Mat
ncnn::Mat convertToNCNN(const cv::Mat& opencvMat)
{
if (opencvMat.depth() != CV_8U || opencvMat.channels() != 3) {
std::cerr << "Unsupported input format. Expected BGR 8-bit image." << std::endl;
return ncnn::Mat(); // Return empty or error-handling code
}
int width = opencvMat.cols;
int height = opencvMat.rows;
// Create an empty NCNN Mat with the same size and float32 data type
ncnn::Mat ncnnMat(width, height, ncnn::DataType::f32);
// Convert OpenCV's uchar* to ncnn's float* directly (assuming BGR order)
float* ncnn_data = static_cast<float*>(ncnnMat.data);
const uchar* opencv_data = opencvMat.ptr();
for (int y = 0; y < height; ++y) {
for (int x = 0; x < width; ++x) {
int bgra_index = y * width * 4 + x * 4;
ncnn_data[y * width + x] = static_cast<float>(opencv_data[bgra_index + 2]); // Blue channel
ncnn_data[y * width + x + 1] = static_cast<float>(opencv_data[bgra_index + 1]); // Green channel
ncnn_data[y * width + x + 2] = static_cast<float>(opencv_data[bgra_index + 0]); // Red channel
// Alpha channel is often not used, so you can skip it if needed
}
}
return ncnnMat;
}
```
注意,上述代码假设输入的OpenCV图像是BGR格式。如果有其他颜色空间或者通道数量不同的情况,你需要相应地调整读取和赋值部分。
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