ITK学习笔记——中值滤波和均值滤波

均值滤波和和中值滤波都可以起到平滑图像，虑去噪声的功能。
均值滤波采用线性的方法，平均整个窗口范围内的像素值，均值滤波本身存在着固有的缺陷，即它不能很好地保护图像细节，在图像去噪的同时也破坏了图像的细节部分，从而使图像变得模糊，不能很好地去除噪声点。均值滤波对高斯噪声表现较好，对椒盐噪声表现较差。
中值滤波采用非线性的方法，它在平滑脉冲噪声方面非常有效,同时它可以保护图像尖锐的边缘，选择适当的点来替代污染点的值，所以处理效果好，对椒盐噪声表现较好，对高斯噪声表现较差。

中值滤波：

#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkMedianImageFilter.h"
#include "itkSubtractImageFilter.h"

#include "itksys/SystemTools.hxx"
#include <sstream>

#include "QuickView.h"

int main(int argc, char * argv[])
{
  std::string inputFilename = "C:/input/Lenna.jpeg";

  typedef itk::Image<float, 2 >                         ImageType;
  typedef itk::ImageFileReader<ImageType>               ReaderType;
  typedef itk::MedianImageFilter<ImageType, ImageType > FilterType;
  typedef itk::SubtractImageFilter<ImageType>           SubtractType;

  ReaderType::Pointer reader = ReaderType::New();
  reader->SetFileName( inputFilename );

  FilterType::Pointer medianFilter = FilterType::New();
  FilterType::InputSizeType radius;
  radius.Fill(2);

  medianFilter->SetRadius(radius);
  medianFilter->SetInput( reader->GetOutput() );

  SubtractType::Pointer diff = SubtractType::New();
  diff->SetInput1(reader->GetOutput());
  diff->SetInput2(medianFilter->GetOutput());

  QuickView viewer;
  viewer.AddImage(
    reader->GetOutput(),true,
    itksys::SystemTools::GetFilenameName(inputFilename));  

  std::stringstream desc;
  desc << "MedianImageFilter, radius = " << radius;
  viewer.AddImage(
    medianFilter->GetOutput(),
    true,
    desc.str());  

  std::stringstream desc2;
  desc2 << "Original - Median";
  viewer.AddImage(
    diff->GetOutput(),
    true,
    desc2.str());  

  viewer.Visualize();

  return EXIT_SUCCESS;
}

由于读取没用RGB格式，所以会自动转化为灰度图。

均值滤波：

#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkMeanImageFilter.h"
#include "itkSubtractImageFilter.h"

#include "QuickView.h"

int main(int argc, char * argv[])
{
  typedef itk::Image< unsigned char, 2 >                UnsignedCharImageType;
  typedef itk::Image< float, 2 >                        FloatImageType;
  typedef itk::ImageFileReader< UnsignedCharImageType > ReaderType;
  typedef itk::MeanImageFilter<
    UnsignedCharImageType, UnsignedCharImageType > filterType;
  typedef itk::SubtractImageFilter<UnsignedCharImageType, UnsignedCharImageType, FloatImageType>           SubtractType;

  ReaderType::Pointer reader = ReaderType::New();
  reader->SetFileName( "C:/input/Lenna.jpeg" );

  filterType::Pointer meanFilter = filterType::New();
  meanFilter->SetInput( reader->GetOutput() );

  SubtractType::Pointer diff = SubtractType::New();
  diff->SetInput1(reader->GetOutput());
  diff->SetInput2(meanFilter->GetOutput());

  QuickView viewer;
  viewer.AddImage(
    reader->GetOutput(),true,

    itksys::SystemTools::GetFilenameName("C:/input/Lenna.jpeg"));  

  std::stringstream desc;
  desc << "Mean";
  viewer.AddImage(
    meanFilter->GetOutput(),
    true,
    desc.str());  

  std::stringstream desc2;
  desc2 << "Original - Mean";
  viewer.AddImage(
    diff->GetOutput(),
    true,
    desc2.str());  

  viewer.Visualize();

  return EXIT_SUCCESS;
}

来源：https://blog.csdn.net/u010409517/article/details/99234546