+ /**
+ ** Initialize the histogram
+ */
+ void initializeHistogram(vtkImageData* img);
+ /**
+ ** Returns two vectors, the grey level of the point and its value, the value is between [0,1]
+ **/
+ void GetValuesPointsFunction(std::vector<double>& greylevel,std::vector<double>& value);
+
+ /**
+ ** Returns two vectors, the grey level of the point and its value, the red, green
+ ** and blue value is between [0,1]
+ **/
+ void GetValuesColorPointsFunction(std::vector<double>& greylevel,
+ std::vector<double>& red,
+ std::vector<double>& green,
+ std::vector<double>& blue);