I'm writing a program which uses OpenCv neural networks module along with C# and OpenCvSharp library. It must recognise the face of user, so in order to train the network, i need a set of samples. The problem is how to convert a sample image into array suitable for training. What i've got is 200x200 BitMap image, and network with 40000 input neurons, 200 hidden neurons and one output:
CvMat layerSizes = Cv.CreateMat(3, 1, MatrixType.S32C1);
layerSizes[0, 0] = 40000;
layerSizes[1, 0] = 200;
layerSizes[2, 0] = 1;
Network = new CvANN_MLP(layerSizes,MLPActivationFunc.SigmoidSym,0.6,1);
So then I'm trying to convert BitMap image into CvMat array:
private void getTrainingMat(int cell_count, CvMat trainMAt, CvMat responses)
{
CvMat res = Cv.CreateMat(cell_count, 10, MatrixType.F32C1);//10 is a number of samples
responses = Cv.CreateMat(10, 1, MatrixType.F32C1);//array of supposed outputs
int counter = 0;
foreach (Bitmap b in trainSet)
{
IplImage img = BitmapConverter.ToIplImage(b);
Mat imgMat = new Mat(img);
for (int i=0;i<imgMat.Height;i++)
{
for (int j = 0; j < imgMat.Width; j++)
{
int val =imgMat.Get<int>(i, j);
res[counter, 0] = imgMat.Get<int>(i, j);
}
responses[i, 0] = 1;
}
trainMAt = res;
}
}
And then, when trying to train it, I've got this exception:
input training data should be a floating-point matrix withthe number of rows equal to the number of training samples and the number of columns equal to the size of 0-th (input) layer
Code for training:
trainMAt = Cv.CreateMat(inp_layer_size, 10, MatrixType.F32C1);
responses = Cv.CreateMat(inp_layer_size, 1, MatrixType.F32C1);
getTrainingMat(inp_layer_size, trainMAt, responses);
Network.Train(trainMAt, responses, new CvMat(),null, Parameters);
I'm new to OpenCV and I think I did something wrong in converting because of lack of understanding CvMat structure. Where is my error and is there any other way of transforming the bitmap?