|| || || || || || || ||

---

LabHistExtractor.h

Go to the documentation of this file.

#ifndef Impala_Core_VideoSet_LabHistExtractor_h
#define Impala_Core_VideoSet_LabHistExtractor_h

#include "Core/VideoSet/HistogramExtractor.h"

#include "Core/Array/Element/Vec3Real64.h"
#include "Core/Array/Element/Color.h"
#include "Core/Vector/ElemMax.h"
#include "Core/Vector/DivAssign.h"

namespace Impala
{
namespace Core
{
namespace VideoSet
{

class LabHistExtractor : public HistogramExtractor
{

public:

    LabHistExtractor(Reporter* reporter, CmdOptions& options) :
      HistogramExtractor(reporter, options, "labhistogram", 3 * BINS_PER_CHANNEL)
    {
    }

    virtual 
    ~LabHistExtractor()
    {
    }

protected:

    // Lab histogram computation - from Chorus::CxLabHist
    virtual VectorReal64
    ComputeHistogram(Array::Array2dVec3UInt8* image)
    {
        UInt8* data = image->CPB(0, 0);
        const int nPix = image->CW() * image->CH();

        VectorReal64 histogram(GetBinCount());
        Real64* histL = histogram.GetData();
        Real64* histA = histL + BINS_PER_CHANNEL;
        Real64* histB = histA + BINS_PER_CHANNEL;

        for (int i = 0; i < GetBinCount(); i++)
            histL[i] = 0;

        for (int j = 0; j < nPix; j++) 
        {
            const Array::Element::Vec3Real64 pixel = 
                Array::Element::Vec3Real64(data[0], data[1], data[2]);
            const Array::Element::Color crgb(pixel, Array::Element::RGB);

            Array::Element::Color clab = crgb.ToLab();
            Array::Element::Vec3Real64 lab = clab.Value();

            // Assume L between 0 and 100
            int l = ComputeBin(lab.X(), 0.0, 100.0, BINS_PER_CHANNEL);
            histL[l] += 1;

            // Assume a between -90 and 90
            int a = ComputeBin(lab.Y(), -90.0, 90.0, BINS_PER_CHANNEL);
            histA[a] += 1;

            // Assume b between -90 and 90
            int b = ComputeBin(lab.Z(), -90.0, 90.0, BINS_PER_CHANNEL);
            histB[b] += 1;

            data += 3;
        }

        const Real64 factor = nPix;
        Vector::DivAssign(histogram, factor);

        return histogram;
    }


private:

    static const int BINS_PER_CHANNEL = 32;

    ILOG_VAR_DECL;
};

ILOG_VAR_INIT(LabHistExtractor, Impala.Core.VideoSet);


} // namespace VideoSet
} // namespace Core
} // namespace Impala

#endif

---