我正在使用一个 50 帧每秒的相机(在 Ubuntu 环境和 Qt 框架下),并且每隔 20 毫秒我会得到一帧图像进行处理。
我编写了一段代码,从相机读取图像,然后将它们存储在硬盘上。
while(3.14)
{
cv::Mat Camera_Image = Capture_Image();
double T1 = (double)cv::getTickCount();
cv::imwrite (STORE_ADDRESS,Camera_Image);
T1 = (((double)cv::getTickCount() -T1)*1000)/cv::getTickFrequency();
print(T1);
}
当我查看输出时,将单个2048*1080像素大小的图像写入硬盘的时间约为30毫秒。每个图像都是单通道(灰度),但我在硬盘中以.jpg格式写入它们。每个图像在硬盘上的大小约为500K字节。
由于我大约在20毫秒内捕获一帧,因此我无法实时将它们全部写入硬盘。我使用Qthread编写了我的代码并创建了一个队列来查看是否有改进,但结果仍然相同,只是内存开销而已。
是否可能改变这种情况,或者使用其他库更快地将这些图像写入硬盘?如果有Qt解决方案,我也会更喜欢使用它...
此外,我需要将每个单独的帧写入硬盘,因此请不要建议使用Motion压缩算法,因为它们不适用于我的情况....
代码: Mainwindow.cpp
Qlist<cv::Mat> FINAL_IM_VEC;
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
IMREAD *IMR = new IMREAD(this); // an instance of IMREAD Class which reads camera frames
IMWRITE *IMW = new IMWRITE(this); // an instance of IMWRITE Class which Writes camera frames into hard disk
QThread *IMAGE_READ_Thread = new QThread(this);
QThread *Image_Store_Thread = new QThread(this);
connect(IMAGE_READ_Thread,SIGNAL(started()),IMR,SLOT(IMREAD_Process()));
connect(Image_Store_Thread,SIGNAL(started()),IMW,SLOT(IMWrite_Process()));
IMR.moveToThread(IMAGE_READ_Thread);
IMW.moveToThread(Image_Store_Thread);
IMAGE_READ_Thread->start();
Image_Store_Thread->start();
}
imread.hpp
class IMREAD : public QObject
{
Q_OBJECT
public:
explicit IMREAD(QObject *parent = 0);
signals:
public slots:
void IMREAD_Process();
private:
bool Stop;
};
imread.cpp
IMREAD::IMREAD(QObject *parent) :
QObject(parent)
{
this->Stop = false;
}
void IMREAD::IMREAD_Process()
{
while(!Stop)
{
cv::Mat Image = CAM::Campture_F(25);//wait a maximum of 25 milisecond to grab a new frame
if(Image.data())
{
FINAL_IM_VEC.push_back(Image);
}
}
}
}
imwrite.hpp
#ifndef IMWRITE_H
#define IMWRITE_H
#pragma once
#include <QObject>
class IMWRITE : public QObject
{
Q_OBJECT
public:
explicit IMWRITE(QObject *parent = 0);
signals:
public slots:
void IMWrite_Process();
private:
bool Stop;
};
imwrite.cpp
IMWRITE::IMWRITE(QObject *parent) :
QObject(parent)
{
this->Stop =false;
}
void IMWRITE::IMWrite_Process()
{
static int counter = 0;
while(!Stop)
{
for(int i = 0 ; i < FINAL_IM_VEC.size() ; i++)
{
QString address = "/home/Provisioner/ThreadT/Results/" + QString::number(counter++) + ".jpg";
cv::imwrite(address.toUtf8().constData(),FINAL_IM_VEC[i]);
FINAL_IM_VEC.erase(FINAL_IM_VEC.begin() + i);
i--;
}
}
}
由于这只是整个项目的一部分,我已经删除了一些不相关的部分...但它展示了我如何编写多线程代码的整体情况...所以如果有任何问题,请告诉我。
提前致谢。