使用CImg的C ++中的光谱残留显着性检测

问题描述

我正在尝试实现频谱残差方法以进行显着性检测，如本文所述: http://www.klab.caltech.edu/~xhou/papers/cvpr07 .pdf

I'm trying to implement the spectral residual approach for saliency detection, described in this paper:http://www.klab.caltech.edu/~xhou/papers/cvpr07.pdf

在Matlab代码中有一个参考实现，取自他们的网站: http://www.klab.caltech.edu/~xhou/projects/spectralResidual/spectralresidual.html

There is a reference implementation in Matlab Code, taken from their website:http://www.klab.caltech.edu/~xhou/projects/spectralResidual/spectralresidual.html

clear
clc
%% Read image from file
inImg = im2double(rgb2gray(imread('yourImage.jpg')));
inImg = imresize(inImg, 64/size(inImg, 2));
%% Spectral Residual
myFFT = fft2(inImg);
myLogAmplitude = log(abs(myFFT));
myPhase = angle(myFFT);
mySpectralResidual = myLogAmplitude - imfilter(myLogAmplitude, fspecial('average', 3),'replicate');
saliencyMap = abs(ifft2(exp(mySpectralResidual + i*myPhase))).^2;
%% After Effect
saliencyMap = mat2gray(imfilter(saliencyMap, fspecial('gaussian', [10, 10], 2.5)));
imshow(saliencyMap);

我尝试使用CImg将其转换为C ++.我失败的地方是这里:

I've tried to translate it to C++ with CImg.Where I fail is here:

myPhase = angle(myFFT);

在这里

saliencyMap = abs(ifft2(exp(mySpectralResidual + i*myPhase))).^2;

这是我的代码:

#include <CImg.h>
#include <iostream>
using namespace cimg_library;

int main() {

  CImg<unsigned char> image("img2.jpg");

  CImg<float> mask(3,3,1,1,1.0/9.0);

  image.resize(64,64);

  CImgList<float> myFFT = image.get_FFT();

  const CImg<float> MyLogAmplitude = ((myFFT[0].get_pow(2) +  myFFT[1].get_pow(2)).get_sqrt()).get_log(); //Magnitude

  const CImg<float> MyPhase = myFFT[0].get_atan2(myFFT[1]);

  const CImg<float> A = MyLogAmplitude.get_convolve(mask);

  const CImg<float> MySpectralResidual = MyLogAmplitude-A;

  CImgList<float> tmp = CImgList<float>(MyResidual.get_exp(),MyPhase);

  CImgList<float> MySaliencyMap = tmp.get_FFT(true);

  CImgDisplay  draw_disp0(MySaliencyMap,"Image");


  while (!draw_disp0.is_closed()) {

    draw_disp0.wait();

  }
  return 0;
}

有人看到明显的错误吗?

Anybody seen an obvious mistake?

推荐答案

我想我可以在您的代码中看到两个错误:

I think I can see two mistakes in your code :

• 首先，对MyPhase的atan2()调用将参数取反.应该写为

• First, the atan2() call for MyPhase has arguments inverted. Should be written as

const CImg MyPhase = myFFT [1] .get_atan2(myFFT [0]);

const CImg MyPhase = myFFT[1].get_atan2(myFFT[0]);

(但这在这里可能不是什么大问题).

(but this is probably not much of an issue here).

• 第二，更严重的是，您正在对编码为(振幅，相位)的一对复数值进行逆FFT，这不是CImg期望的，因为FFT()函数假定您输入了(对).这可能会在结果上产生巨大的差异.

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