OpenCV写保存完成黑色jpeg [英] OpenCV imwrite saving complete black jpeg
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问题描述
我已经对dft做了一些预处理，我想通过imwrite保存这个图像。
我裁剪的图片包含此信息
output.type 5
output.channels（）1
output.depth（）5
但每次当我保存它给出黑色输出。我检查了旧的现有线程stackoverflow，但似乎不工作为我。
例如
OpenCV2.3 imwrite保存黑色图片
我已经尝试过许多颜色转换和深度转换，但我不知道为什么它不工作。
std :: vector< int> qualityType;
qualityType.push_back（CV_IMWRITE_JPEG_QUALITY）;
qualityType.push_back（90）;
Mat out1，out2;
cv :: cvtColor（output，out1，CV_GRAY2BGR）;
//out1.convertTo(out2,CV_8U,1./256）; //我试过这个太
cv :: imwrite（dft1.jpg，out1，qualityType）; //尝试甚至使用质量类型
imshow显示此图片只有问题出现时，我保存它。 / p>
请帮助
也许我的dft类有问题，因为我每当我使用dft函数那么输出只能与inshow一起工作，但保存不起作用。
CDftRidgeAnalyses :: CDftRidgeAnalyses（void）
{
}
CDftRidgeAnalyses ::〜CDftRidgeAnalyses（void）
{
}
Mat CDftRidgeAnalyses :: GetRidgeAnalyses （Mat inpGray）
{
Mat img = inpGray;
int WidthPadded = 0，HeightPadded = 0;
WidthPadded = img.cols * 2;
HeightPadded = img.rows * 2;
int M = getOptimalDFTSize（img.rows）;
//创建一个高斯高通滤波器5％的傅立叶变换的高度
double db = 0.05 * HeightPadded;
Mat fft = ForierTransform（img.clone（），HeightPadded，WidthPadded）;
Mat ghpf = CreateGaussianHighPassFilter（Size（WidthPadded，HeightPadded），db）;
Mat res;
cv :: mulSpectrums（fft，ghpf，res，DFT_COMPLEX_OUTPUT）;
Mat mag = GetDftToImage（res，img）;
int cx = mag.cols / 2;
int cy = mag.rows / 2;
cv :: Mat croped = mag（cv :: Rect（0,0，cx，cy））;
cv :: threshold（mag，mag，0.019，1，cv :: THRESH_BINARY）;
Mat bgr;
cvtColor（mag，bgr，CV_GRAY2RGB）;
// imshow（XXX，bgr）;
// imshow（croped，croped）;
// imshow（img，img）;
//
// cv :: waitKey（）;
return croped;
}
Mat CDftRidgeAnalyses :: ForierTransform（Mat inpGray，int M，int N）
{
Mat img = inpGray;
int i = img.channels（）;
填充
Mat img2;
img.convertTo（img2，CV_64F，1。/ 255）;
copyMakeBorder（img2，padded，0，M - img2.rows，0，N - img2.cols，BORDER_CONSTANT，Scalar :: all（0））;
Mat element1 = Mat_< float>（padded）;
Mat element2 = Mat :: zeros（padded.size（），CV_32F）;
Mat planes [] = {element1，element2};
Mat complexImg;
merge（planes，2，complexImg）;
dft（complexImg，complexImg，0，img.rows）;
// printMat（complexImg）;
return complexImg;
}
double CDftRidgeAnalyses :: pixelDistance（double u，double v）
{
return cv :: sqrt（u * u + v * v）;
}
double CDftRidgeAnalyses :: gaussianCoeff（double u，double v，double d0）
{
double d = pixelDistance（u，v）;
return 1.0 - cv :: exp（（ - d * d）/（2 * d0 * d0））;
}
cv :: Mat CDftRidgeAnalyses :: CreateGaussianHighPassFilter（cv :: Size size，double cutoff InPixels）
{
Mat ghpf（size，CV_32F）;
cv :: Point center2（（size.width * 0.80），size.width / 2）;
// cv :: Point center2（0,0）;
for（int u = 0; u
for（int v = 0; v
}
}
Mat bmp;
int channels = ghpf.channels（）;
int type = ghpf.type（）;
int depth = ghpf.depth（）;
cv :: cvtColor（ghpf，bmp，CV_GRAY2RGB）;
cv :: cvtColor（ghpf，bmp，CV_GRAY2BGRA）;
// imshow（XXX，bmp）;
int cx = ghpf.cols / 2;
int cy = ghpf.rows / 2;
Mat tmp;
int iExactright =（size.width * 0.59）;
int iExactbottom =（size.height * 0.86）;
// full Mat q0（ghpf，Rect（69,10,400,290））;
// Mat whiteq（ghpf，Rect（0,390,270,330））;
int iMainleft = 0，iMainright = 0;
int iMainBottom = 0，iMainTop = 0;
Mat Quad;
mat ql（ghpf，Rect（190,0,270,330））;
/ **将矩形放在相对于右上角的中间默认过滤器上** /
iMainleft =（size.width * 0.111）;
iMainright =（size.width * 0.402）;
iMainTop =（size.height * 0.484）;
iMainBottom =（size.height * 0.155）;
Quad = ghpf（Rect（iMainleft，iMainTop，iMainright + 6，iMainBottom））;
Mat qTopRight（ghpf，Rect（iExactright，0，iMainright + 6，iMainBottom））;
Quad.copyTo（qTopRight）;
/ **将矩形放在相对于左上角的中间默认过滤器上** /
iMainright =（size.width * 0.402）;
Quad = ghpf（Rect（300，iMainTop，300，iMainBottom））;
Mat qTopLeft（ghpf，Rect（0,0，300，iMainBottom））;
Quad.copyTo（qTopLeft）;
/ **将矩形放在相对于左下角的中间默认过滤器上** /
iMainTop = iMainTop-iMainBottom;
iExactbottom = size.height - iMainBottom;
Quad = ghpf（Rect（300，iMainTop，300，iMainBottom））;
Mat qBottomLeft（ghpf，Rect（0，iExactbottom，300，iMainBottom））;
Quad.copyTo（qBottomLeft）;
/ **将矩形放在相对于右下角的中间默认过滤器上** /
iMainleft =（size.width * 0.111）;
iMainright =（size.width * 0.402）;
Quad = ghpf（Rect（iMainleft，iMainTop，iMainright + 6，iMainBottom））;
mat qBottomRight（ghpf，Rect（iExactright，iExactbottom，iMainright + 6，iMainBottom））;
Quad.copyTo（qBottomRight）;
//删除中矩形[circle]
iMainright =（size.width * 0.402）;
Quad = ghpf（Rect（0，iMainTop + iMainTop，size.width，iMainBottom + iMainBottom-130））;
Mat qMiddle（ghpf，Rect（0，iMainTop + 150，size.width，iMainBottom + iMainBottom-130））;
Quad.copyTo（qMiddle）;
qMiddle = ghpf（Rect（0，iMainTop-10，size.width，iMainBottom + iMainBottom-130））;
Quad.copyTo（qMiddle）;
normalize（ghpf，ghpf，0，1，CV_MINMAX）;
/ * Mat x;
cv :: resize（ghpf，x，cv :: Size（400,700））;
imshow（fftXhighpass2，x）; * /
Filter = ghpf;
填充
copyMakeBorder（ghpf，padded，0，size.height - ghpf.rows，0，size.width - ghpf.cols，BORDER_CONSTANT，Scalar :: all（0））;
Mat planes [] = {Mat_< float>（padded），Mat :: zeros（padded.size（），CV_32F）};
Mat complexImg;
merge（planes，2，complexImg）;
返回complexImg;
}
Mat CDftRidgeAnalyses :: GetDftToImage（Mat res，Mat orgImage）
{
idft（res，res，DFT_COMPLEX_OUTPUT，orgImage.rows）;
填充
copyMakeBorder（orgImage，padded，0，orgImage.rows，0，orgImage.cols，BORDER_CONSTANT，Scalar :: all（0））;
Mat planes [] = {Mat_< float>（padded），Mat :: zeros（padded.size（），CV_32F）};
split（res，planes）;
magnitude（planes [0]，planes [1]，planes [0]）;
Mat mag = planes [0];
mag + = Scalar :: all（1）;
// log（mag，mag）;
//裁剪谱图，如果它有奇数行或列
mag = mag（Rect（0，0，mag.cols& -2，mag.rows& ; -2））;
normalize（mag，mag，1,0，CV_MINMAX）;
return mag;
}
我想要保存的输出来自
Mat org = imread（4.png，CV_LOAD_IMAGE_GRAYSCALE）;
Mat re;
resize（org，re，cv :: Size（311,519））;
Mat xyz = CDftRidgeAnalyses :: GetRidgeAnalyses（re）;
cv :: imwrite（dft1.jpg，xyz）;
这里矩阵xyz有这些值
output.type（）5
output.channels（）1
output.depth（）5
我希望你们现在可以帮助我更好...也许从复杂的过滤器转换后我失去了一些点？ ？
解决方案
这种感觉像浮点数和整数的问题。当图像有浮点值时，opencv的imshow（）期望这些值在0和1之间：
http://opencv.itseez.com/modules/highgui/doc/user_interface.html?highlight= imshow＃cv2.imshow
我不太确定什么imwrite（）与浮点图像，因为我不能在这里读取：
无论如何， imwrite可能希望在0和255之间的整数值，并且可能只是将浮点数转换为整数。在这种情况下，几乎所有的东西都被强制转换为0（例如0.8被转换为0），因此你的黑色图像。
尝试将图像转换为CV_U8CX。或者，这里是我用来调试这样的opencv问题：
void printType（Mat& mat）{
if（mat.depth（）== CV_8U）printf（unsigned char（％d），mat.channels（））;
else if（mat.depth（）== CV_8S）printf（signed char（％d），mat.channels（））;
else if（mat.depth（）== CV_16U）printf（unsigned short（％d），mat.channels（））;
else if（mat.depth（）== CV_16S）printf（signed short（％d），mat.channels（））;
else if（mat.depth（）== CV_32S）printf（signed int（％d），mat.channels（））;
else if（mat.depth（）== CV_32F）printf（float（％d），mat.channels（））;
else if（mat.depth（）== CV_64F）printf（double（％d），mat.channels
else printf（unknown（％d），mat.channels（））;
}
void printInfo（const char * prefix，Mat& mat）{
printf（％s：，prefix）;
printf（dim（％d，％d），mat.rows，mat.cols）;
printType（mat）;
printf（\\\
）;
}
void printInfo（Mat&mat）{
printf（dim（％d，％d），mat.rows，mat.cols）;
printType（mat）;
printf（\\\
）;
}
这种方式你可以找到你的cv :: Mat在它的数据-field。
PS：我没有调试你的代码，所以保持开放其他问题的原因。
I have done some pre processing for dft , and i am trying to save this image by imwrite.
My cropped image has this information
output.type() 5
output.channels() 1
output.depth() 5
But everytime when i save it gives black output. I have checked old existing threads of stackoverflow but all seems not working for me. e.g. OpenCV2.3 imwrite saves black image
I have tried many color conversions and depth conversion as well but i dont know why it does not work.
std::vector<int> qualityType;
qualityType.push_back(CV_IMWRITE_JPEG_QUALITY);
qualityType.push_back(90);
Mat out1,out2;
cv::cvtColor(output, out1, CV_GRAY2BGR);
//out1.convertTo(out2,CV_8U,1./256); // i tried this too
cv::imwrite("dft1.jpg",out1,qualityType); // tried even using quality type
imshow display this image fine only problem comes when i save it.
please help
[EDIT] Maybe my dft class that i made has problem because i whenever i use dft function then the output can only work with inshow but for save it does not work.
CDftRidgeAnalyses::CDftRidgeAnalyses(void)
{
}
CDftRidgeAnalyses::~CDftRidgeAnalyses(void)
{
}
Mat CDftRidgeAnalyses::GetRidgeAnalyses(Mat inpGray)
{
Mat img = inpGray;
int WidthPadded=0,HeightPadded=0;
WidthPadded=img.cols*2;
HeightPadded=img.rows*2;
int M = getOptimalDFTSize( img.rows );
//Create a Gaussian Highpass filter 5% the height of the Fourier transform
double db = 0.05 * HeightPadded;
Mat fft = ForierTransform(img.clone(),HeightPadded,WidthPadded);
Mat ghpf = CreateGaussianHighPassFilter(Size(WidthPadded, HeightPadded), db);
Mat res;
cv::mulSpectrums(fft,ghpf,res,DFT_COMPLEX_OUTPUT);
Mat mag = GetDftToImage(res,img);
int cx = mag.cols/2;
int cy = mag.rows/2;
cv::Mat croped = mag(cv::Rect(0,0,cx, cy));
cv::threshold(mag, mag, 0.019, 1, cv::THRESH_BINARY);
Mat bgr;
cvtColor(mag,bgr,CV_GRAY2RGB);
//imshow("XXX",bgr);
//imshow("croped", croped);
//imshow("img",img);
//
//cv::waitKey();
return croped;
}
Mat CDftRidgeAnalyses::ForierTransform(Mat inpGray,int M,int N)
{
Mat img = inpGray;
int i = img.channels();
Mat padded;
Mat img2;
img.convertTo(img2,CV_64F,1./255);
copyMakeBorder(img2, padded, 0, M - img2.rows, 0, N - img2.cols, BORDER_CONSTANT, Scalar::all(0));
Mat element1 = Mat_<float>(padded);
Mat element2 = Mat::zeros(padded.size(), CV_32F);
Mat planes[] = {element1, element2};
Mat complexImg;
merge(planes, 2, complexImg);
dft(complexImg, complexImg ,0, img.rows);
//printMat(complexImg);
return complexImg;
}
double CDftRidgeAnalyses::pixelDistance(double u, double v)
{
return cv::sqrt(u*u + v*v);
}
double CDftRidgeAnalyses::gaussianCoeff(double u, double v, double d0)
{
double d = pixelDistance(u, v);
return 1.0 - cv::exp((-d*d) / (2*d0*d0));
}
cv::Mat CDftRidgeAnalyses::CreateGaussianHighPassFilter(cv::Size size, double cutoffInPixels)
{
Mat ghpf(size, CV_32F);
cv::Point center2((size.width*0.80), size.width/2);
//cv::Point center2(0,0);
for(int u = 0; u < ghpf.rows; u++)
{
for(int v = 0; v < ghpf.cols; v++)
{
ghpf.at<float>(u, v) = gaussianCoeff(u - center2.x, v - center2.y, cutoffInPixels);
}
}
Mat bmp;
int channels = ghpf.channels();
int type = ghpf.type();
int depth = ghpf.depth();
cv::cvtColor(ghpf,bmp,CV_GRAY2RGB);
cv::cvtColor(ghpf,bmp,CV_GRAY2BGRA);
//imshow("XXX",bmp);
int cx = ghpf.cols/2;
int cy = ghpf.rows/2;
Mat tmp;
int iExactright = (size.width*0.59);
int iExactbottom = (size.height*0.86);
//full Mat q0(ghpf, Rect(69,10,400,290));
// Mat whiteq(ghpf, Rect(0,390,270,330));
int iMainleft=0, iMainright=0;
int iMainBottom=0,iMainTop=0;
Mat Quad;
Mat ql(ghpf, Rect(190,0,270,330));
/** Make the rectangle on middle default filter with respect to top right angle**/
iMainleft=(size.width*0.111);
iMainright=(size.width*0.402);
iMainTop=(size.height*0.484);
iMainBottom = (size.height*0.155);
Quad = ghpf(Rect(iMainleft,iMainTop,iMainright+6,iMainBottom));
Mat qTopRight(ghpf, Rect(iExactright,0, iMainright+6, iMainBottom));
Quad.copyTo(qTopRight);
/** Make the rectangle on middle default filter with respect to top left angle**/
iMainright=(size.width*0.402);
Quad = ghpf(Rect(300,iMainTop,300,iMainBottom));
Mat qTopLeft(ghpf, Rect(0,0, 300, iMainBottom));
Quad.copyTo(qTopLeft);
/** Make the rectangle on middle default filter with respect to bottom left angle**/
iMainTop = iMainTop-iMainBottom;
iExactbottom = size.height - iMainBottom;
Quad = ghpf(Rect(300,iMainTop,300,iMainBottom));
Mat qBottomLeft(ghpf, Rect(0,iExactbottom, 300, iMainBottom));
Quad.copyTo(qBottomLeft);
/** Make the rectangle on middle default filter with respect to bottom right angle**/
iMainleft=(size.width*0.111);
iMainright=(size.width*0.402);
Quad = ghpf(Rect(iMainleft,iMainTop,iMainright+6,iMainBottom));
Mat qBottomRight(ghpf, Rect(iExactright,iExactbottom, iMainright+6, iMainBottom));
Quad.copyTo(qBottomRight);
// remove middle rectangle [ circle ]
iMainright=(size.width*0.402);
Quad = ghpf(Rect(0,iMainTop+iMainTop,size.width,iMainBottom+iMainBottom-130));
Mat qMiddle(ghpf,Rect(0,iMainTop+150,size.width,iMainBottom+iMainBottom-130));
Quad.copyTo(qMiddle);
qMiddle =ghpf(Rect(0,iMainTop-10,size.width,iMainBottom+iMainBottom-130));
Quad.copyTo(qMiddle);
normalize(ghpf, ghpf, 0, 1, CV_MINMAX);
/*Mat x;
cv::resize(ghpf,x,cv::Size(400,700));
imshow("fftXhighpass2", x);*/
Filter = ghpf;
Mat padded;
copyMakeBorder(ghpf, padded, 0, size.height - ghpf.rows, 0, size.width - ghpf.cols, BORDER_CONSTANT, Scalar::all(0));
Mat planes[] = {Mat_<float>(padded), Mat::zeros(padded.size(), CV_32F)};
Mat complexImg;
merge(planes, 2, complexImg);
return complexImg;
}
Mat CDftRidgeAnalyses::GetDftToImage(Mat res,Mat orgImage)
{
idft(res,res,DFT_COMPLEX_OUTPUT,orgImage.rows);
Mat padded;
copyMakeBorder(orgImage, padded, 0,orgImage.rows, 0, orgImage.cols, BORDER_CONSTANT, Scalar::all(0));
Mat planes[] = {Mat_<float>(padded), Mat::zeros(padded.size(), CV_32F)};
split(res, planes);
magnitude(planes[0], planes[1], planes[0]);
Mat mag = planes[0];
mag += Scalar::all(1);
// log(mag, mag);
// crop the spectrum, if it has an odd number of rows or columns
mag = mag(Rect(0, 0, mag.cols & -2, mag.rows & -2));
normalize(mag, mag, 1, 0, CV_MINMAX);
return mag;
}
The output that i am trying to save is from
Mat org = imread("4.png",CV_LOAD_IMAGE_GRAYSCALE);
Mat re;
resize(org,re,cv::Size(311,519));
Mat xyz = CDftRidgeAnalyses::GetRidgeAnalyses(re);
cv::imwrite("dft1.jpg",xyz);
here the matrix xyz has these values
output.type() 5
output.channels() 1
output.depth() 5
I hope you guys now can help me more better... maybe after converion from complex filter i am losing some points????
解决方案
This 'feels' like a problem with floating point numbers and integers. When your image has floating point values, the imshow() of opencv expects these values to be between 0 and 1:
http://opencv.itseez.com/modules/highgui/doc/user_interface.html?highlight=imshow#cv2.imshow
I'm not quite sure what imwrite() does with floating point images, as I could not read it here:
Anyhow, imwrite might expect integer values between 0 and 255, and might simply cast floats to integers. In this case, almost everything is casted to 0 (i.g. 0.8 is casted to 0), hence your black images.
Try to convert your images to CV_U8CX. Alternatively, here is something I use to debug such opencv problems:
void printType(Mat &mat) {
if(mat.depth() == CV_8U) printf("unsigned char(%d)", mat.channels());
else if(mat.depth() == CV_8S) printf("signed char(%d)", mat.channels());
else if(mat.depth() == CV_16U) printf("unsigned short(%d)", mat.channels());
else if(mat.depth() == CV_16S) printf("signed short(%d)", mat.channels());
else if(mat.depth() == CV_32S) printf("signed int(%d)", mat.channels());
else if(mat.depth() == CV_32F) printf("float(%d)", mat.channels());
else if(mat.depth() == CV_64F) printf("double(%d)", mat.channels());
else printf("unknown(%d)", mat.channels());
}
void printInfo(const char *prefix, Mat &mat) {
printf("%s: ", prefix);
printf("dim(%d, %d)", mat.rows, mat.cols);
printType(mat);
printf("\n");
}
void printInfo(Mat &mat) {
printf("dim(%d, %d)", mat.rows, mat.cols);
printType(mat);
printf("\n");
}
This way you can find out what your cv::Mat has in it's data-field.
PS: I did not debug your code throughly, so stay open to other probleem causes.
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