自己尝试实现了一次数组模拟卷积过程
代码如下
//
// main.cpp
// CNN
//
// Created by HuangZhennan on 2019/1/12.
// Copyright © 2019 HuangZhennan. All rights reserved.
//
#include <iostream>
using namespace std;
int main(int argc, const char * argv[]) {
/*
float input[8][8] = {{1,2,3,4,5,6,7,8},
{1,2,3,4,5,6,7,8},
{1,2,3,4,5,6,7,8},
{1,2,3,4,5,6,7,8},
{1,2,3,4,5,6,7,8},
{1,2,3,4,5,6,7,8},
{1,2,3,4,5,6,7,8},
{1,2,3,4,5,6,7,8}};
*/
float input[4][4] = {{1,2,3,4},
{1,2,3,4},
{1,2,3,4},
{1,2,3,4}};
float kernel[3][3] = {{1,1,1},{1,2,1},{1,1,1}};
int kernelSize = 3;
int featureSize = 4;
int stride = 1;
int outputSize = featureSize-kernelSize+1;
float* inputCol = new float[featureSize*featureSize];
float* kerCol = new float[kernelSize*kernelSize];
float* outputCol = new float[outputSize*outputSize]; //未使用im2col
float* outputCol2 = new float[outputSize*outputSize]; //使用im2col
memset(inputCol, 0, sizeof(float)*featureSize*featureSize);
memset(outputCol, 0, sizeof(float)*outputSize*outputSize);
memset(outputCol2, 0, sizeof(float)*outputSize*outputSize);
int convertW = kernelSize*kernelSize; //卷积转矩阵乘法宽,即卷积核单元个数
int convertH = outputSize*outputSize; //卷积转矩阵乘法,即卷积次数
float* convertA = new float[convertW * convertH]; //转换后的矩阵
memset(convertA, 0, sizeof(float)*convertW * convertH);
for(int i = 0; i < featureSize; i++)
{
for(int j = 0; j < featureSize; j++)
{
inputCol[featureSize*i+j] = input[i][j]; //将二维矩阵转为1维向量,输入特征图
}
}
for(int i = 0; i < kernelSize; i++)
{
for(int j = 0; j < kernelSize; j++)
{
kerCol[kernelSize*i+j] = kernel[i][j]; //将二维矩阵转为1维向量,卷积核
}
}
for(int i = 0; i < outputSize; i++)
{
for(int j = 0; j < outputSize; j++)
{
for (int k = 0; k < kernelSize; k++)
{
for (int m = 0; m < kernelSize; m++)
{
outputCol[i*outputSize+j]+=kerCol[k*kernelSize+m]*inputCol[(i*stride)*featureSize+j*stride+k*featureSize+m]; //卷积
}
}
}
}
for(int i = 0; i < outputSize; i++)
{
for(int j = 0; j < outputSize; j++)
{
for (int k = 0; k<convertW; k++) {
int row = k/kernelSize;
int col = k%kernelSize;
int start = i*featureSize+j;
float value = inputCol[start+row*featureSize+col];
int index = (i*outputSize+j)*convertW+k;
convertA[index] = value; //卷积转为生成操作
//convertA[(i*featureSize+j)*convertW+k] = 0;
}
}
}
cout<<"featuremap:"<<endl;
for(int i = 0; i < featureSize; i++)
{
for(int j = 0; j < featureSize; j++)
{
cout<<inputCol[i*featureSize+j]<<" ";
}
cout<<endl;
}
cout<<"convertA:"<<endl;
for(int i = 0; i < convertH; i++)
{
for(int j = 0; j < convertW; j++)
{
cout<<convertA[i*convertW+j]<<" ";
}
cout<<endl;
}
for(int i = 0; i < outputSize; i++)
{
for(int j = 0; j < outputSize; j++)
{
for(int k = 0; k < convertW; k++)
{
outputCol2[i*outputSize+j] += convertA[(i*outputSize+j)*convertW+k]*kerCol[k]; //矩阵乘法
}
}
}
cout<<"kernel:"<<endl;
for(int i = 0; i < kernelSize; i++)
{
for(int j = 0; j < kernelSize; j++)
{
cout<<kerCol[i*kernelSize+j]<<" ";
}
cout<<endl;
}
cout<<"result:"<<endl;
for(int i = 0; i < outputSize; i++)
{
for(int j = 0; j < outputSize; j++)
{
cout<<outputCol[i*outputSize+j]<<" ";
}
cout<<endl;
}
cout<<"result2:"<<endl;
for(int i = 0; i < outputSize; i++)
{
for(int j = 0; j < outputSize; j++)
{
cout<<outputCol2[i*outputSize+j]<<" ";
}
cout<<endl;
}
//float iConvert[6][6] = {0};
return 0;
}