求教：C语言中__int64 的详细作用，用法

Posted 2023-04-11

getimage() 保存图像函数
功能： 函数getimage()保存左上角与右下角所定义的屏幕上像素图形到指定的内存区域。
用法： 该函数调用方式为void getimage(int left,int top,int right,int bottom,void *buf);
说明： 函数中参数(left,top)为要保存的图像屏幕的左上角，(right,bottom)为其右下角，buf指向保存图像的内存地址。调用getimage()保存屏幕图像，可用imagesize()函数确定保存图像所需字节数，再用malloc()函数分配存储图像的内存(内存分配必须小于64KB)，还可以用下面函数putimage()输出getimage()保存的屏幕图像。
这个函数对应的头文件为graphics.h
返回值： 无
例： 把带有两对角线的矩形拷贝到屏幕其它位置上：
#include<garphics.h>
#include<stdlib.h>
#include<conio.h>
void main()

int driver,mode;
unsigned size;
void *buf;
driver=DETECT;
mode=0;
initgraph(&driver,&mode,"");
sector(15);
rectangle(20,20,200,200);
setcolor(RED);
line(20,20,200,200);
setcolor(GREEN);
line(20,200,200,20);
getch();
size=imagesize(20,20,200,200);
if(size!=-1)
buf=malloc(size);
if(buf)
getimage(20,20,200,200,buf);
putimage(100,100,buf,COPy_PUT);
putimage(300,50,buf,COPy_PUT);


outtext("press a key");
getch();
restorecrtmode()

参考技术A 一个长度为64Bit的整数数据而已，无他。本回答被提问者采纳

openCV2中的SCalar的详细用法和用处能介绍下么？

如题，OpenCV2的啊。不是openCV1里面的cvScalar！！！！
另外，链接文档什么的都欢迎哟~

参考技术A class Scalar_

Template class for a 4-element vector derived from Vec.
template<typename _Tp> class CV_EXPORTS Scalar_ : public Vec<_Tp, 4>

public:
//! various constructors
Scalar_();
Scalar_(_Tp v0, _Tp v1, _Tp v2=0, _Tp v3=0);
Scalar_(const CvScalar& s);
Scalar_(_Tp v0);

//! returns a scalar with all elements set to v0
static Scalar_<_Tp> all(_Tp v0);
//! conversion to the old-style CvScalar
operator CvScalar() const;

//! conversion to another data type
template<typename T2> operator Scalar_<T2>() const;

//! per-element product
Scalar_<_Tp> mul(const Scalar_<_Tp>& t, double scale=1 ) const;

// returns (v0, -v1, -v2, -v3)
Scalar_<_Tp> conj() const;

// returns true iff v1 == v2 == v3 == 0
bool isReal() const;
;

typedef Scalar_<double> Scalar;

Being derived from Vec<_Tp, 4> , Scalar_ and Scalar can be used just as typical 4-element vectors. In addition, they can be converted to/from CvScalar . The type Scalar is widely used in OpenCV to pass pixel values. 参考技术B cvZero(CvArr* arr)该函数作用主要主要变量arr清零做处避免系统自配值确定性程序影响现预料结与功能相同函数cvSetZero(CvArr* arr)希望能帮助 参考技术C 整个项目的结构图：

编写DetectFaceDemo.java,代码如下：

[java] view
plaincopyprint?

package com.njupt.zhb.test;

import org.opencv.core.Core;

import org.opencv.core.Mat;

import org.opencv.core.MatOfRect;

import org.opencv.core.Point;

import org.opencv.core.Rect;

import org.opencv.core.Scalar;

import org.opencv.highgui.Highgui;

import org.opencv.objdetect.CascadeClassifier;

//

// Detects faces in an image, draws boxes around them, and writes the results

// to "faceDetection.png".

//

public class DetectFaceDemo

public void run()

System.out.println("\nRunning DetectFaceDemo");

System.out.println(getClass().getResource("lbpcascade_frontalface.xml").getPath());

// Create a face detector from the cascade file in the resources

// directory.

//CascadeClassifier faceDetector = new CascadeClassifier(getClass().getResource("lbpcascade_frontalface.xml").getPath());

//Mat image = Highgui.imread(getClass().getResource("lena.png").getPath());

//注意：源程序的路径会多打印一个‘/’，因此总是出现如下错误

/*

* Detected 0 faces Writing faceDetection.png libpng warning: Image

* width is zero in IHDR libpng warning: Image height is zero in IHDR

* libpng error: Invalid IHDR data

*/

//因此，我们将第一个字符去掉

String xmlfilePath=getClass().getResource("lbpcascade_frontalface.xml").getPath().substring(1);

CascadeClassifier faceDetector = new CascadeClassifier(xmlfilePath);

Mat image = Highgui.imread(getClass().getResource("we.jpg").getPath().substring(1));

// Detect faces in the image.

// MatOfRect is a special container class for Rect.

MatOfRect faceDetections = new MatOfRect();

faceDetector.detectMultiScale(image, faceDetections);

System.out.println(String.format("Detected %s faces", faceDetections.toArray().length));

// Draw a bounding box around each face.

for (Rect rect : faceDetections.toArray())

Core.rectangle(image, new Point(rect.x, rect.y), new Point(rect.x + rect.width, rect.y + rect.height), new Scalar(0, 255, 0));



// Save the visualized detection.

String filename = "faceDetection.png";

System.out.println(String.format("Writing %s", filename));

Highgui.imwrite(filename, image);




package com.njupt.zhb.test;
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.MatOfRect;
import org.opencv.core.Point;
import org.opencv.core.Rect;
import org.opencv.core.Scalar;
import org.opencv.highgui.Highgui;
import org.opencv.objdetect.CascadeClassifier;

//
// Detects faces in an image, draws boxes around them, and writes the results
// to "faceDetection.png".
//
public class DetectFaceDemo
public void run()
System.out.println("\nRunning DetectFaceDemo");
System.out.println(getClass().getResource("lbpcascade_frontalface.xml").getPath());
// Create a face detector from the cascade file in the resources
// directory.
//CascadeClassifier faceDetector = new CascadeClassifier(getClass().getResource("lbpcascade_frontalface.xml").getPath());
//Mat image = Highgui.imread(getClass().getResource("lena.png").getPath());
//注意：源程序的路径会多打印一个‘/’，因此总是出现如下错误
/*
* Detected 0 faces Writing faceDetection.png libpng warning: Image
* width is zero in IHDR libpng warning: Image height is zero in IHDR
* libpng error: Invalid IHDR data
*/
//因此，我们将第一个字符去掉
String xmlfilePath=getClass().getResource("lbpcascade_frontalface.xml").getPath().substring(1);
CascadeClassifier faceDetector = new CascadeClassifier(xmlfilePath);
Mat image = Highgui.imread(getClass().getResource("we.jpg").getPath().substring(1));
// Detect faces in the image.
// MatOfRect is a special container class for Rect.
MatOfRect faceDetections = new MatOfRect();
faceDetector.detectMultiScale(image, faceDetections);

System.out.println(String.format("Detected %s faces", faceDetections.toArray().length));

// Draw a bounding box around each face.
for (Rect rect : faceDetections.toArray())
Core.rectangle(image, new Point(rect.x, rect.y), new Point(rect.x + rect.width, rect.y + rect.height), new Scalar(0, 255, 0));


// Save the visualized detection.
String filename = "faceDetection.png";
System.out.println(String.format("Writing %s", filename));
Highgui.imwrite(filename, image);



3.编写测试类：

[java] view
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package com.njupt.zhb.test;

public class TestMain

public static void main(String[] args)

System.out.println("Hello, OpenCV");

// Load the native library.

System.loadLibrary("opencv_java246");

new DetectFaceDemo().run();





//运行结果:

//Hello, OpenCV

//

//Running DetectFaceDemo

///E:/eclipse_Jee/workspace/JavaOpenCV246/bin/com/njupt/zhb/test/lbpcascade_frontalface.xml

//Detected 8 faces

//Writing faceDetection.png
package com.njupt.zhb.test;
public class TestMain
public static void main(String[] args)
System.out.println("Hello, OpenCV");
// Load the native library.
System.loadLibrary("opencv_java246");
new DetectFaceDemo().run();


//运行结果:
//Hello, OpenCV
//
//Running DetectFaceDemo
///E:/eclipse_Jee/workspace/JavaOpenCV246/bin/com/njupt/zhb/test/lbpcascade_frontalface.xml
//Detected 8 faces
//Writing faceDetection.png