我实现了一个修改版的Caffe C++示例,虽然它运行良好,但速度非常慢,因为它只接受一个图片。理想情况下,我希望将Caffe传递一个包含200张图像的向量,并返回每个图像的最佳预测结果。我得到了Fanglin Wang的大力帮助,并实现了他的一些建议,但仍然有一些问题需要解决,如何从每个图像中检索出最佳结果。
现在,Classify方法传递了一个
现在,Classify方法传递了一个
cv::Mat
对象的向量(变量input_channels
),这是一组灰度浮点图像。我已经在代码中删除了预处理方法,因为我不需要将这些图像转换为浮点数或减去平均图像。我还试图摆脱N
变量,因为我只想返回每个图像的前一个预测和概率。#include "Classifier.h"
using namespace caffe;
using std::string;
Classifier::Classifier(const string& model_file, const string& trained_file, const string& label_file) {
#ifdef CPU_ONLY
Caffe::set_mode(Caffe::CPU);
#else
Caffe::set_mode(Caffe::GPU);
#endif
/* Load the network. */
net_.reset(new Net<float>(model_file, TEST));
net_->CopyTrainedLayersFrom(trained_file);
Blob<float>* input_layer = net_->input_blobs()[0];
num_channels_ = input_layer->channels();
input_geometry_ = cv::Size(input_layer->width(), input_layer->height());
/* Load labels. */
std::ifstream labels(label_file.c_str());
CHECK(labels) << "Unable to open labels file " << label_file;
string line;
while (std::getline(labels, line))
labels_.push_back(string(line));
Blob<float>* output_layer = net_->output_blobs()[0];
CHECK_EQ(labels_.size(), output_layer->channels())
<< "Number of labels is different from the output layer dimension.";
}
static bool PairCompare(const std::pair<float, int>& lhs, const std::pair<float, int>& rhs) {
return lhs.first > rhs.first;
}
/* Return the indices of the top N values of vector v. */
static std::vector<int> Argmax(const std::vector<float>& v, int N) {
std::vector<std::pair<float, int> > pairs;
for (size_t i = 0; i < v.size(); ++i)
pairs.push_back(std::make_pair(v[i], i));
std::partial_sort(pairs.begin(), pairs.begin() + N, pairs.end(), PairCompare);
std::vector<int> result;
for (int i = 0; i < N; ++i)
result.push_back(pairs[i].second);
return result;
}
/* Return the top N predictions. */
std::vector<Prediction> Classifier::Classify(const std::vector<cv::Mat> &input_channels) {
std::vector<float> output = Predict(input_channels);
std::vector<int> maxN = Argmax(output, 1);
int idx = maxN[0];
predictions.push_back(std::make_pair(labels_[idx], output[idx]));
return predictions;
}
std::vector<float> Classifier::Predict(const std::vector<cv::Mat> &input_channels, int num_images) {
Blob<float>* input_layer = net_->input_blobs()[0];
input_layer->Reshape(num_images, num_channels_,
input_geometry_.height, input_geometry_.width);
/* Forward dimension change to all layers. */
net_->Reshape();
WrapInputLayer(&input_channels);
net_->ForwardPrefilled();
/* Copy the output layer to a std::vector */
Blob<float>* output_layer = net_->output_blobs()[0];
const float* begin = output_layer->cpu_data();
const float* end = begin + num_images * output_layer->channels();
return std::vector<float>(begin, end);
}
/* Wrap the input layer of the network in separate cv::Mat objects (one per channel). This way we save one memcpy operation and we don't need to rely on cudaMemcpy2D. The last preprocessing operation will write the separate channels directly to the input layer. */
void Classifier::WrapInputLayer(std::vector<cv::Mat>* input_channels) {
Blob<float>* input_layer = net_->input_blobs()[0];
int width = input_layer->width();
int height = input_layer->height();
float* input_data = input_layer->mutable_cpu_data();
for (int i = 0; i < input_layer->channels() * num_images; ++i) {
cv::Mat channel(height, width, CV_32FC1, input_data);
input_channels->push_back(channel);
input_data += width * height;
}
}
更新
非常感谢你的帮助,Shai。我按照你的建议进行了更改,但似乎出现了一些奇怪的编译问题,我无法解决(我已经解决了一些问题)。
这些是我所做的更改:
头文件:
#ifndef __CLASSIFIER_H__
#define __CLASSIFIER_H__
#include <caffe/caffe.hpp>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <algorithm>
#include <iosfwd>
#include <memory>
#include <string>
#include <utility>
#include <vector>
using namespace caffe; // NOLINT(build/namespaces)
using std::string;
/* Pair (label, confidence) representing a prediction. */
typedef std::pair<string, float> Prediction;
class Classifier {
public:
Classifier(const string& model_file,
const string& trained_file,
const string& label_file);
std::vector< std::pair<int,float> > Classify(const std::vector<cv::Mat>& img);
private:
std::vector< std::vector<float> > Predict(const std::vector<cv::Mat>& img, int nImages);
void WrapInputLayer(std::vector<cv::Mat>* input_channels, int nImages);
void Preprocess(const std::vector<cv::Mat>& img,
std::vector<cv::Mat>* input_channels, int nImages);
private:
shared_ptr<Net<float> > net_;
cv::Size input_geometry_;
int num_channels_;
std::vector<string> labels_;
};
#endif /* __CLASSIFIER_H__ */
文件类:
#define CPU_ONLY
#include "Classifier.h"
using namespace caffe; // NOLINT(build/namespaces)
using std::string;
Classifier::Classifier(const string& model_file,
const string& trained_file,
const string& label_file) {
#ifdef CPU_ONLY
Caffe::set_mode(Caffe::CPU);
#else
Caffe::set_mode(Caffe::GPU);
#endif
/* Load the network. */
net_.reset(new Net<float>(model_file, TEST));
net_->CopyTrainedLayersFrom(trained_file);
CHECK_EQ(net_->num_inputs(), 1) << "Network should have exactly one input.";
CHECK_EQ(net_->num_outputs(), 1) << "Network should have exactly one output.";
Blob<float>* input_layer = net_->input_blobs()[0];
num_channels_ = input_layer->channels();
CHECK(num_channels_ == 3 || num_channels_ == 1)
<< "Input layer should have 1 or 3 channels.";
input_geometry_ = cv::Size(input_layer->width(), input_layer->height());
/* Load labels. */
std::ifstream labels(label_file.c_str());
CHECK(labels) << "Unable to open labels file " << label_file;
string line;
while (std::getline(labels, line))
labels_.push_back(string(line));
Blob<float>* output_layer = net_->output_blobs()[0];
CHECK_EQ(labels_.size(), output_layer->channels())
<< "Number of labels is different from the output layer dimension.";
}
static bool PairCompare(const std::pair<float, int>& lhs,
const std::pair<float, int>& rhs) {
return lhs.first > rhs.first;
}
/* Return the indices of the top N values of vector v. */
static std::vector<int> Argmax(const std::vector<float>& v, int N) {
std::vector<std::pair<float, int> > pairs;
for (size_t i = 0; i < v.size(); ++i)
pairs.push_back(std::make_pair(v[i], i));
std::partial_sort(pairs.begin(), pairs.begin() + N, pairs.end(), PairCompare);
std::vector<int> result;
for (int i = 0; i < N; ++i)
result.push_back(pairs[i].second);
return result;
}
std::vector< std::pair<int,float> > Classifier::Classify(const std::vector<cv::Mat>& img) {
std::vector< std::vector<float> > output = Predict(img, img.size());
std::vector< std::pair<int,float> > predictions;
for ( int i = 0 ; i < output.size(); i++ ) {
std::vector<int> maxN = Argmax(output[i], 1);
int idx = maxN[0];
predictions.push_back(std::make_pair(labels_[idx], output[idx]));
}
return predictions;
}
std::vector< std::vector<float> > Classifier::Predict(const std::vector<cv::Mat>& img, int nImages) {
Blob<float>* input_layer = net_->input_blobs()[0];
input_layer->Reshape(nImages, num_channels_,
input_geometry_.height, input_geometry_.width);
/* Forward dimension change to all layers. */
net_->Reshape();
std::vector<cv::Mat> input_channels;
WrapInputLayer(&input_channels, nImages);
Preprocess(img, &input_channels, nImages);
net_->ForwardPrefilled();
/* Copy the output layer to a std::vector */
Blob<float>* output_layer = net_->output_blobs()[0];
std::vector <std::vector<float> > ret;
for (int i = 0; i < nImages; i++) {
const float* begin = output_layer->cpu_data() + i*output_layer->channels();
const float* end = begin + output_layer->channels();
ret.push_back( std::vector<float>(begin, end) );
}
return ret;
}
/* Wrap the input layer of the network in separate cv::Mat objects
* (one per channel). This way we save one memcpy operation and we
* don't need to rely on cudaMemcpy2D. The last preprocessing
* operation will write the separate channels directly to the input
* layer. */
void Classifier::WrapInputLayer(std::vector<cv::Mat>* input_channels, int nImages) {
Blob<float>* input_layer = net_->input_blobs()[0];
int width = input_layer->width();
int height = input_layer->height();
float* input_data = input_layer->mutable_cpu_data();
for (int i = 0; i < input_layer->channels()* nImages; ++i) {
cv::Mat channel(height, width, CV_32FC1, input_data);
input_channels->push_back(channel);
input_data += width * height;
}
}
void Classifier::Preprocess(const std::vector<cv::Mat>& img,
std::vector<cv::Mat>* input_channels, int nImages) {
for (int i = 0; i < nImages; i++) {
vector<cv::Mat> channels;
cv::split(img[i], channels);
for (int j = 0; j < channels.size(); j++){
channels[j].copyTo((*input_channels)[i*num_channels_[0]+j]);
}
}
}