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I have this error:

OpenCV Error: Assertion failed (type == B.type() && (type == CV_32FC1 || type == CV_64FC1 ||
type == CV_32FC2 || type == CV_64FC2)) in gemm, file /build/buildd/opencv-
2.3.1/modules/core/src/matmul.cpp, line 701 terminate called after throwing an instan
ce of 'cv::Exception' what(): /build/buildd/opencv-2.3.1/modules/core/
src/matmul.cpp:701: error: (-215) type == B.type() && (type == CV_32FC1 || 
type == CV_64FC1 || type == CV_32FC2 || type == CV_64FC2) in function gemm

I m sure is generated in a function I use because I used a print function after using that function. Originally what I have to do is translate to C with openCV this matlab's code:

function Xdecorr= color Decorrelation(X,numChannels)

if numChannels >1
mu=mean(X);
X=bsxfun(@minus,X,mu);
A=X'*X;
[V,D,notused]=svd(A);
Xdecorr=X*V;

else
 Xdecorr=Xdecorr;
end

I translated in C as:

  Mat colorDecorrelation(Mat img,int numColComp){

  Mat V,D,A,mu,Xdecorr,img_tr;
  SVD svd;

   if(numColComp>1){

    mu=mean(img);
    subtract(img,mu,img);
    transpose(img,img_tr);
        A = img_tr*img;
        V = svd(A).u;
        Xdecorr = img*V;
   }
   else
   Xdecorr = img;

    return Xdecorr;
    }

The error is for sure when I do : A=img_tr*img

I

I have a Mat object and a bidimensional array. I need to multiply them and have a new Mat object. I had to realize imf=imf.*filt in Matlab

for(m=0;m<rows;m++){
  for(n=0;n<cols;n++){

    imfft= imfft*filter[m][n];

   }
 }

Hi people,

I have a question.

Code:

  int rows= img.rows;
  int cols= img.cols;
  int channels=img.channels();

Does this code give to me the numbers of rows,cols and channels of an image I read with imread function? Does the image I use must be in the same path of the project to be read?

Hi i m running a programm I finish . I see this as error:

   OpenCV Error: Bad flag (parameter or structure field) (Unrecognized or
   unsupported array type) in cvGetMat, file
   /build/buildd/opencv-2.3.1/modules/core/src/array.cpp, line 2482 terminate
   called after throwing an instance of 'cv::Exception' what():
  /build/buildd/opencv-2.3.1/modules/core/src/array.cpp:2482: error: (-206)
  Unrecognized or unsupported array type in function cvGetMat

I suppose it s an error about the type of image I use. What I do is take an image and work with it in two different ways, for if the image is in grey scale or RBG. I suppose I did some errors with some functions need in paramethers the type. For example:

  img= image.zeros(rows,cols,CV_32F);

I don t know the difference in the last paramether (the type), can I use for example image.type() ? There is something it explain good the type in openCV. Thanks

Hi I have to translate from MAtlav to C this lines:

 x=reshape(img,r*c,numChannels);
 x=reshape(img,r,c,numChannels);
 x=reshape(img,r,c);
 x=reshape(img,r*c,scalesNumber);

I didn t understand well this function, but I tried with:

 x=img.reshape(numColComp,rows*cols);
 x=img.reshape(numColComp,rows);
 x=img.reshape(numColComp,rows); //or x=img.reshape(0,rows)
 x=img.reshape(0,rows);

I suppose I m doing it bad

I mean why argv[1] is the path of an image passed by command line?

Load an image by passing the path or by a command line interface (I don t know if the right term in English) . Howewer the code works.I just want to understand better why is used in that way. How is used about the command line loading in that way

Load an image by passing the path or by a command line interface (I don t know if the right term in English) . Howewer the code works.I just want to understand better why is used in that way. How is used about the command line loading in that way

Hi people, I have this part of code and I d like to undrestand better it.

  Mat img=imread(".....");   //... is a path

  if(argc>1)
    img=imread(argv[1]);

  if(img.empty(){
    cerr <<" Error message:" << argv[1];
    return 1;
  }

  if (img.empty(){
    cout << "the image is empty\n";
    return -1;
  }

First line load an image by passing directly the path of the image. After it load an image if is passed by command line, as cmd, or terminal. Can I understand better how. Why is it used argv[1]? Is it a need to use 2 time the control about if the imafe is loaded? I understand is a control firstly for the second kind of loading image and after for the 1st (load by adding path)

Hi perople,

do you know if exist some code or just tell me some function of openCv can be used to recognize some part of a picture. I mean the target is:

from a picture ( for example a face of a person) underline or point out some parts I want (for example nose, eyes...etc).

Thank you

I solved all the problems . Thanks

I did some modification in the file opened with

sudo gedit /etc/ld.so.conf.d/opencv.conf

I added: / /usr/local/opencv/ then type: sudo ldconfig

Now Consolle in Eclipse give me : CAN NOT OPEN IMAGE FILE :

Ok. I had the same problems and same errors. But adding libraries in setting of the cpp file it does not show any error now. But compiling I have this error in the Consolle (using Eclipse):

/home/elvio/workspace/main-cpp/Debug/main-cpp: error while loading shared libraries: libopencv_core.so.2.4: cannot open shared object file: No such file or directory

it shows:

/usr/local/lib/libopencv_calib3d.so /usr/local/lib/libopencv_contrib.so /usr/local/lib/libopencv_core.so /usr/local/lib/libopencv_features2d.so /usr/local/lib/libopencv_flann.so /usr/local/lib/libopencv_gpu.so /usr/local/lib/libopencv_highgui.so /usr/local/lib/libopencv_imgproc.so /usr/local/lib/libopencv_legacy.so /usr/local/lib/libopencv_ml.so /usr/local/lib/libopencv_nonfree.so /usr/local/lib/libopencv_objdetect.so /usr/local/lib/libopencv_ocl.so /usr/local/lib/libopencv_photo.so /usr/local/lib/libopencv_stitching.so /usr/local/lib/libopencv_superres.so /usr/local/lib/libopencv_ts.a /usr/local/lib/libopencv_video.so /usr/local/lib/libopencv_videostab.so -lrt -lpthread -lm -ldl

HI man, I did how you said. Now I recompile (a project that must work) and I have 100 errors of same type:

undefined reference to 'cv:: .......... " , where ....is a function with his input's type.

Maybe is it because I have to add in PROJECT-->PROPERTIES-->C/C++ BUILD-->SETTINGS the various libraries and includes....where can I find it?

Do I have to delete the previous version?

I try with http://answers.opencv.org/question/26250/opencv-linux-installation/

but doesn t workk. Howewer I had a previous version on my ububtu. do I have ti delete it before? How?

I have to do:

Initial decorrelation on RGB color components of each image / frame to have an efficient codification ( without duplication ) of the input data through analysis of the principal components (PCA ), adapted to local image statistics ( rbgDecorr in AWS.m of Matlab ) .We obtain the three components Z1 , Z2 and Z3 in the block figure Whitening Color . This operation is performed by colorDecorrelation( ) function . I have yet done colorDecorrelation function and it works. But in main I don t know how to do all is written before and in the image. P.D. All must done in a MAT object

Hi,

I have a project on image processing. It doesn' t work. It s finished, but I don' t understand how correct the error. the project is very short, about 300 lines. The project come from a work (it works well) in Matlab and so I did a sort of translation from Matlab I have a documentation that explain what to do too and I can explain what t do. knowledge of : OpenCV,C++ and eventually Matlab

Contact to : [email protected]

Oh, maybe I understand reading better. 1 grayscale image for each mono colored picture, as in the picture attached.if you open it, you ll understan easily. Thanks

I did not understand your answer. Howewer we have an image.from this we obtain Rgb images inthe same array 3dimensional. In 3rd dimension you have the 3 images. After the matrix is whitened for every pixel.

do you know how can I solve this part?

Yes it s more or less what u said. the C is the operation of whitening. It s done in the function colorDecorrelation. The work done in Matlab works , so it can be just a translation from it to C++ as I done in code. I suppose it s right this part. It s the first & second part I didn t do. Thanks to help me

Hello keghn. Thanks for reply. You are very close. A & B ok. The whitening procedure consisting in decorrelation and variance normalization is simply applied to the r, g, b components of the image. Being x1=r, x2=g and x3=b the RGB coordinates of any pixel in the image, they are involved in the transformation (x1,x2,x3)→(z1,z2,z3). Thereby I obtain z contain z1 to z3 components.Z is whitened with a new vector associated to each pixel. If x is the representation of the image in the original space, y the representation in principal components, and z (z-scores) the corresponding representation in the whitened coordinates. That is, x = (xj) →y = (yj) →z = (zj) with j=1…M, where M is the number of components. Look the picture I attached to understand better

Hi people. I hope you can help me to solve this problem I can not solve from long time. I have to finish a project about image processing and I saw an error in the initial step. I have a code in Matlab I have to obtain it in C++ with OpenCV. I did not study Matlab and C++ neither too (just C) , so I don t know how continue my work. Please help.

As in this picture : C:\fakepath\imag.png

the initial target is :

Initial decorrelation on RGB color components of each image/frame to have an efficient codification (without duplication)of the input data through analysis of the principal components(PCA),adapted to local image statistics (rgbDecorr in Matlab's code). We obtain so 3 components Z1,Z2,Z3 in the image attached in the block figure Whitening color. This operation is performed by colorDecorrelaion function().

Matlab' s code :

 //initial stuff
 numColComp = compc; % 3 in case of color images, 1 in grayscale images
 inComp = reshape(im, r*c, numColComp);

 Decorr=colorDecorrelation(inComp,numColComp);

 rgbDecorr= reshape(Decorr, r, c, numColComp); //HERE

 clear Decorr;

 % Fourier transform of the achromatic component
 [imfft,sz2filt,padSize]=FourierTransform2D(rgbDecorr(:,:,1),achrLambda_max);

 //more stuff

 conspic2 = zeros(r,c);

   for i_c_comp=2:numColComp

     % FILTERING CHROMATIC COMPONENT rgbDecorr(:,:,2) and  rgbDecorr(:,:,2)
    [imfft,sz2filt,padSize]=FourierTransform2D(rgbDecorr(:,:,i_c_comp),chrLambda_max);

I don t understand in Matlab where is obtained the 3 components. I supposed where I commented HERE and I suppose but I m not sure that is created a 3dimensional array where in a dimension is located the 3 components. Am I right? How to do it and how to obtain this stuff? I don t understan where it obtain this 3 images of the image attached by the input image:

Howewer here the colorDecorrelation function MAtlab's code:

function Xdecorr=colorDecorrelation(X,numColComp){

 if numColComp>1  %color images                  
 mu = mean(X); %mean of each feature of the original data
 X = bsxfun(@minus, X, mu);
 A = X'*X; 
 [V,D,notused] = svd(A);

 Xdecorr=X*V;

 else % in case of a grayscale image
   Xdecorr = X;
   end

So In C++ what I did is:

//initial statements and Image control if empty or not

inCompImg = img.reshape(numColComp,(img.rows)*(img.cols));
imgDecorr = colorDecorrelation(inCompImg,img.channels());

 // TO RETURN INITIAL VALUES BEACUSE I HAD TO CHANGE IT IN COLORDECORRELATION FUNCTION
 imgDecorr.convertTo(rgbDecorrImg,CV_8UC3); 

 //HERE ERROR FOR SURE
 rgbDecorrImg = rgbDecorrImg.reshape(numColComp,imgDecorr.rows);


...
...

 Mat colorDecorrelation(Mat img,int numColComp){

 Mat V,D,A,Xdecorr,img_tr,img_f;
 Scalar mu;
 SVD svd;

  if(numColComp>1){

    //I have to convert because of gemm function need a float
    img.convertTo(img_f,CV_32FC3);
    img_f=img_f.reshape(1,img.rows*img.cols); // 1 channel

     mu=mean(img_f); //media degli elementi della matrice
     subtract(img_f,mu,img_f);
    transpose(img_f,img_tr);
     A = img_tr * img_f;
    V = svd(A).u; 
    Xdecorr = img_f*V;

  }
   else 
    Xdecorr=img;

     return Xdecorr;
   }

Hi people. Im doing a translation from Matlab to C++. That' s code in Matlab I have to put in C++

 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % Color Decorrelation
 % Input Parameters:
 %  im           - image matrix
 %  numColComp   - number of image channels
 %
 % Output value:
 %  Xdecorr  - decorrelated image, same dimensions as the original one
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

 function Xdecorr=colorDecorrelation(X,numColComp)

 if numColComp>1  %color images
 mu = mean(X); %mean of each feature of the original data
 X = bsxfun(@minus, X, mu);
 A = X'*X;   %cavariance matrix
 [V,D,notused] = svd(A);

 Xdecorr=X*V;

 else % in case of a grayscale image
    Xdecorr = X;
 end

My translation in C++

 Mat colorDecorrelation(Mat img,int numColComp){

 Mat V,D,A,Xdecorr,img_tr,img_f;
 Scalar mu;
 SVD svd;

 if(numColComp>1){

    //I have to convert because of gemm function need a float
    img.convertTo(img_f,CV_32FC3);
    img_f=img_f.reshape(1,img.rows*img.cols); // 1 channel

     mu=mean(img_f); 
     subtract(img_f,mu,img_f);
    transpose(img_f,img_tr);
     A = img_tr * img_f;
    V = svd(A).u; 
    Xdecorr = img_f*V;

 }
  else 
   Xdecorr=img;

 return Xdecorr;
 }

Do you think is it ok?