Convolution.hpp

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template<class Numeric>
std::ostream& operator<<(std::ostream& out, const std::vector<Numeric>& vector){
    for(uint i = 0; i < vector.size(); i++){
        out << vector[i] << " "; 
    }
    return out;
}

template<class Numeric>
std::vector<Numeric> convolve1D(const std::vector<Numeric>& _source, const std::vector<Numeric>& _kernel, int _offset, ConvolutionPadding _padding, ConvolutionResult _resultType){
    _resultType = (_padding == CIRCULAR) ? SAME : _resultType;
    bool inverted = (_source.size() < _kernel.size());
    const std::vector<Numeric>& source = (inverted) ? _kernel : _source;
    const std::vector<Numeric>& kernel = (inverted) ? _source : _kernel;
    unsigned int size  = _source.size() + (_resultType == FULL) * (_kernel.size() - 1);
    std::vector<Numeric> result(size);
    
    unsigned int i = 0;
    for( ; i < result.size(); i++){
        result[i] = 0;
        
        int j = (int)i - (int)kernel.size() + 1 ;
        for(; j <= (int)i && j < _offset; j++){
            Numeric pad = 0;
            switch(_padding) {
                case ZERO:
                    pad = 0; break;
                case SPECULAR:
                    pad = source[_offset - j]; break;
                case CIRCULAR:
                    pad = source[source.size() + j -_offset]; break;
            }
            result[i] += pad * kernel[i - j];
        }
        
        for( ; j <= (int)i && j < (int)source.size() + _offset; j++){
            result[i] += source[j - _offset] * kernel[i - j];
        }
        
        for( ; j <= (int)i; j++){
            Numeric pad = 0;
            switch (_padding){
                case ZERO:
                    pad = 0; break;
                case SPECULAR:
                    pad = source[2*source.size() - 1 - j + _offset]; break;
                case CIRCULAR:
                    pad = source[j - _offset -source.size()]; break;
            }
            result[i] += pad * kernel[i - j];
        }
    }
/*    for( ; i < result.size(); i++){
        result[i] = 0;
        
        int j = (int)i - (int)kernel.size() + 1;
        for(; j <= (int)i; j++){
            Numeric pad = 0;
            switch (_padding){
                case ZERO:
                    pad = 0; break;
                case SPECULAR:
                    pad = source[source.size() - j]; break;
                case CIRCULAR:
                    pad = source[j]; break;
            }
            result[i] += pad * kernel[i - j];
        }
    }*/
    
    return result;
}

template<class Numeric>
std::vector<Numeric> besselKernel1D(Numeric _sigma, unsigned int _kernelSize){
    unsigned int size = (_kernelSize % 2) ? _kernelSize : _kernelSize + 1;
    std::vector<Numeric> result(size);
    Numeric accumulator = 0;
    
    for(unsigned int i = 0; i < size; i++){
        result[i] = exp(_sigma) * boost::math::cyl_bessel_i(i - 0.5*(size-1),_sigma);
        accumulator += result[i];
    }
    
    for(unsigned int i = 0; i < size; i++){
        result[i] = result[i] / accumulator;
    }
    
    return result;
}

template<class Numeric>
std::vector<Numeric> gaussianKernel1D(Numeric sigma, unsigned int _kernelSize){
    unsigned int size = (_kernelSize % 2) ? _kernelSize : _kernelSize + 1;
    std::vector<Numeric> result(size);
    Numeric accumulator = 0;
    
    for(unsigned int i = 0; i < size; i++){
        Numeric x = i - 0.5*(size-1);
        result[i] = exp(-x*x/(2*sigma/* * sigma */));
        accumulator += result[i];
    }
    
    for(unsigned int i = 0; i < size; i++){
        result[i] = result[i] / accumulator;
    }
    
    return result;
}

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flirtlib
Author(s): Bhaskara Marthi, Gian Diego Tipaldi
autogenerated on Fri Jan 11 11:15:28 2013