ifstream
is
(
"test.yuv"
,
ifstream
::
in
|
ios
::
binary
)
;
is
.
seekg
(
0
,
is
.
end
)
;
int
length
=
is
.
tellg
(
)
;
cout
<<
"****** test.yuv length = "
<<
length
<<
endl
;
is
.
seekg
(
0
,
is
.
beg
)
;
char
*
buffer
=
new
char
[
length
]
;
is
.
read
(
buffer
,
length
)
;
int
iWidth
=
640
;
int
iHeight
=
480
;
int
iImageSize
=
iWidth
*
iHeight
*
3
/
2
;
cv
::
Mat
yuvImg
(
iHeight
*
3
/
2
,
iWidth
,
CV_8UC1
)
;
cv
::
Mat
rgbImg
(
iHeight
,
iWidth
,
CV_8UC1
)
;
memcpy
(
yuvImg
.
data
,
buffer
,
iImageSize
*
sizeof
(
unsigned
char
)
)
;
cv
::
cvtColor
(
yuvImg
,
rgbImg
,
cv
::
COLOR_YUV2BGR_I420
)
;
cv
::
imwrite
(
"./test.jpg"
,
rgbImg
)
;
delete
[
]
buffer
;
is
.
close
(
)
;
参考代码二（yuv 转 jpg，彩色，数据内存拷贝）：
clock_gettime(CLOCK_BOOTTIME, &time1);
int iWidth = 640;
int iHeight = 480;
int iImageSize = iWidth*iHeight*3/2;
//CV_8UC1---8位无符号单通道矩阵
cv::Mat yuvImg(iHeight * 3 / 2, iWidth, CV_8UC1);
cv::Mat rgbImg(iHeight,iWidth,CV_8UC3);
memcpy(yuvImg.data, vpc->data, iImageSize * sizeof(unsigned char));
//cv::cvtColor(yuvImg, rgbImg, cv::COLOR_YUV2BGR_I420);
//cv::cvtColor(yuvImg, rgbImg, cv::CV_YUV2RGBA_NV21);
cv::cvtColor(yuvImg, rgbImg, cv::COLOR_YUV2RGBA_NV21);
//jpgData->data = rgbImg.data;
//jpgData->dataSize = rgbImg.cols * rgbImg.rows;
//cout << "****** jpg cols = " << rgbImg.cols << endl;
//cout << "****** jpg rows = " << rgbImg.rows << endl;
//cout << "****** jpg channels = " << rgbImg.channels() << endl;
//cout << "****** jpg channels = " << rgbImg.channels() << endl;//返回数组元素的总数
//printf("******* jpg w = %d, h = %d,c = %d\n",rgbImg.cols,rgbImg.rows,rgbImg.channels());
//printf("******* jpg elemSize = %d,total = %d\n",rgbImg.elemSize(),rgbImg.total());
//cout << "****** w = " << rgbImg.cols << " , h = " << rgbImg.rows << " , c = " << rgbImg.channels() << endl;
//cout << "****** elemSize = " << rgbImg.elemSize() << " , total = " << rgbImg.total() << endl;
std::vector<unsigned char> dataEncode;
std::vector<int> quality;
quality.push_back(100);
//quality.push_back(cv::CV_IMWRITE_JPEG_QUALITY);
quality.push_back(50);//进行50%压缩
cv::imencode(".jpg",rgbImg,dataEncode,quality);
cout << "****** jpg size = " << dataEncode.size() << endl;
//char * buffer = new char[460800];
unsigned char *jpgBuff = new unsigned char[512000];//500k
size_t jpgSize = dataEncode.size();
for(int i=0;i<jpgSize;i++)*(jpgBuff+i) = dataEncode[i];
if(saveMum < 200)
saveMum++;
if(saveMum%10 == 0)
snprintf(cSaveFile, sizeof(cSaveFile), "img_640x480_%d.%s", saveMum, "jpg");
fOut=fopen(cSaveFile,"wb");
fwrite(jpgBuff, jpgSize, 1, fOut);
fclose(fOut);
clock_gettime(CLOCK_BOOTTIME, &time2);
printf("openCV yuv2jpg times: %03lu ms\n", (time2.tv_sec - time1.tv_sec) *1000 + (time2.tv_nsec - time1.tv_nsec)/1000000);
// 1. 打开图片文件 ifstream is("test.yuv", ifstream::in | ios::binary); // 2. 计算图片长度 is.seekg(0, is.end); int length = is.tellg(); cout << "****** test.yuv length = " << length << endl; is.seekg(0, is.beg); // 3. 创建内存缓存区 char * buffer .
C++在内存中将bmp转JPG。
VS2013，mfc，将大的bmp或者jpg用opencv读取、缩小后保存为bmp，再将bmp转jpg。jpg数据是在内存中的
bmp转jpg
OpenCV是一个基于Apache2.0许可（开源）发行的跨平台计算机视觉和机器学习软件库，可以运行在Linux、Windows、Android和Mac OS操作系统上。 [1] 它轻量级而且高效——由一系列 C 函数和少量 C++ 类构成，同时提供了Python、Ruby、MATLAB等语言的接口，实现了图像处理和计算机视觉方面的很多通用算法。
OpenCV用C++语言编写，它具有C ++，Python，Java和MATLAB接口，并支持Windows，Linux，Android和Mac OS，OpenCV主要倾向于实时视觉应用，并在可用时利用MMX和SSE指令， 如今也提供对于C#、Ch、Ruby，GO的支持。
如果是把YUV灰度图(只有Y分量)转化为Mat1 cv::Mat cv_img;
2 cv::Mat cv_yuv(height, width, CV_8UC1, pFrame);//pFrame为YUV数据地址
3 cv_img = cv::Mat(height, width, CV_LOAD_IMAGE_COLOR);
4 cv::cvtColor(cv_yuv, cv_...
昨天刚和同事一起去采集一些场地数据，用板子拍摄然后实时传到电脑上，得到的是 NV21 的 YUV 格式的照片，然后暂时需要将他们批量处理成 jpg 的文件方便在 windows 上面看。参考同事的代码，写了一个 c++ 的脚本，简简单单的一个程序写了我半天，哎 c++ 的知识还是太不扎实。
#include <iostream>
#include <io.h&...
启动MySQL报错:ERROR 2003 (HY000): Can‘t connect to MySQL server on ‘localhost‘ (10061)
yleaves_:
启动MySQL报错:ERROR 2003 (HY000): Can‘t connect to MySQL server on ‘localhost‘ (10061)
qq_43683965:
