还要有一个坐标平移到中心的操作

//start

#include "drawarea.h"

#include <qDebug>

void show(cmat & src){

int hi = src.size();

int wi = src[0].size();

int i,j;

for (i=0;i<hi;i++){

for (j=0;j<wi;j++){

qDebug()<<" ("<<src[i][j].real() <<" , "<<src[i][j].imag()<<")";

}

qDebug()<<endl;

}

qDebug()<<endl;

}

cmat mk(int hi,int wi){

int i,j;

cmat src;

for (i=0;i<hi;i++){

cline line;

for (j=0;j<wi;j++){

line.push_back(cpl());

}

src.push_back(line);

}

return src;

}

void Drawarea::mkdft(){

QPixmap pix = QPixmap(fname);

// pix.scaled(this->size());

QImage src = pix.toImage();

int hi= src.height();

int wi =src.width();

cmat datred= mk(wi,hi);

cmat datgr = mk(wi,hi);

cmat datbu = mk(wi,hi);

int i,j;

for (i=0;i<wi;i++)

for (j=0;j<hi;j++){//wi hi !!!

QRgb tmp = src.pixel(i,j);

int reg = qRed(tmp);

int green = qGreen(tmp);

int blue = qBlue(tmp);

datred[i][j]=cpl(reg);

datgr[i][j]=cpl(green);

datbu[i][j]=cpl(blue);

}

// ::show(datred);

cmat fa = dft2(datred);

cmat fb = dft2(datgr);

cmat fc = dft2(datbu);

qDebug()<<"dft:\n";

// ::show(fa);

for (i=0;i<wi;i++)

for (j=0;j<hi;j++){

int a=(int)(fa[i][j].real()*150);

fix(a);

int b=(int)(fb[i][j].real()*150);

fix(b);

int c=(int)(fc[i][j].real()*150);

fix(c);

src.setPixel(i,j,qRgb(a,b,c));

}

for (i=0;i<wi;i++)

for (j=0;j<hi;j++){

img.setPixel((i+wi/2)%wi,(j+hi/2)%hi,src.pixel(i,j));

}

this->update();

}

cline dft(cline& src){

int len = src.size();

int k,i,j;

cline dest;

for (k=0;k<len;k++){

cline line;

double base = -2.0*PI*k/(double)len;

for (i=0;i<len;i++){

double tmp = base*i;

cpl nd = exp(cpl(0,tmp));

line.push_back(nd);

}

cpl ans;

for (i=0;i<len;i++){

ans+=(src[i]*line[i]);

}

ans/=cpl(len,0);

dest.push_back(ans);

}

return dest;

}

cmat dft2(cmat & src){

int hi = src.size();

int wi = src[0].size();

int i,j;

cmat tmp = mk(hi,wi);

for (i=0;i<hi;i++){

tmp[i]=dft(src[i]);

}

cmat dest=mk(hi,wi);

for (j=0;j<wi;j++){

cline col;

for (i=0;i<hi;i++){

col.push_back(tmp[i][j]);

}

cline dcol=dft(col);

for (i=0;i<hi;i++){

dest[i][j]=dcol[i];

}

}

return dest;

}

Drawarea::Drawarea(QWidget * parent):QWidget(parent)

{

// QLabel * lab =new QLabel("maio",this);

fname="";

deta=0;

}

void Drawarea::fix(int & dat){

if (dat>COL)

dat=COL;

if (dat<0)

dat=0;

}

void Drawarea::setfile(QString fin){

fname=fin;

QPixmap pix = QPixmap(fname);

//pix.scaled(this->size());

img = pix.toImage();

this->update();

}

void Drawarea::setdeta(int dat){

deta=dat;

this->update();

}

void Drawarea::savefile(QString fsave){

this->img.save(fsave);

}

void Drawarea::paintEvent(QPaintEvent *event){

QPainter g(this);

if (fname.isEmpty()){

QFont chfont("楷体",14,72);

g.setFont(chfont);

g.drawText(this->width()/2-150 , this->height()/2,"please open a image file");

}else{

/*

QPixmap pix = QPixmap(fname);

pix.scaled(this->size());

img = pix.toImage();

int hi= img.height();

int wi =img.width();

int i,j;

for (i=0;i<wi;i++)

for (j=0;j<hi;j++){

QRgb tmp = img.pixel(i,j);

int reg = qRed(tmp);

int green = qGreen(tmp);

int blue = qBlue(tmp);

reg+=deta;

green+=deta;

blue+=deta;

fix(reg);

fix(green);

fix(blue);

img.setPixel(i,j,qRgb(reg,green,blue));

}

*/

//g.drawImage(this->rect(),img);

g.drawImage(0,0,img);

}

}

//end