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/* Copyright (C) 2016 - IIT Bombay - FOSSEE
This file must be used under the terms of the CeCILL.
This source file is licensed as described in the file COPYING, which
you should have received as part of this distribution. The terms
are also available at
http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt
Author: Ukasha Noor
Organization: FOSSEE, IIT Bombay
Email: toolbox@scilab.in
*/
#include "dct.h"
/*#include <fftw3.h>*/
#include <math.h>
void sdcta(float *in,int row,int col,int sign,float *out)
{
int i,j,k,u,v;
int n;
int x,y;
float res,ress;
float re,z,q,m;
if(sign==-1)
{
if(row==1)
{
n=col;
for(u=0;u<row;u++)
{
for(v=0;v<col;v++)
{
x=v*row+u;
out[x]=0;
for(i=0;i<row;i++)
{
for(j=0;j<col;j++)
{
y=row*j+i;
out[x]+=in[y]*(cos(((M_PI)*(y+1-1./2.)*(x))/n));
}
}
if(x==0)
out[x]*=1./(sqrt(n));
else
{
float res=2./n;
out[x]*=sqrt(res);
}
}
}
}
else
{
n=col*row;
for(u=0;u<row;u++)
{
for(v=0;v<col;v++)
{
x=v*row+u;
out[x]=0;
for(i=0;i<row;i++)
{
re=0;
for(j=0;j<col;j++)
{
m=(float)in[j*row+i];
z=(float)(((float)j+1.0/2.0)*(float)v);
q=(float)(M_PI/(float)col);
re+=m*(cos(q*z));
}
z=(float)(((float)i+1.0/2.0)*(float)u);
q=(float)(M_PI/(float)row);
out[x]+=re*(cos(q*z));
}
if(u==0)
{
out[x]/=sqrt((float)row);
if(v==0)
out[x]/=sqrt((float)col);
else
out[x]*=sqrt(2./col);
}
else
{
out[x]*=sqrt(2./row);
if(v==0)
out[x]/=sqrt((float)col);
else
out[x]*=sqrt(2./col);
}
}
}
}
}
else if(sign==1)
{
n=col;
if(row==1)
{
res=1./sqrt(n);
ress=sqrt(2./n);
for(u=0;u<row;u++)
{
for(v=0;v<col;v++)
{
x=v*row+u;
out[x]=0;
for(i=0;i<row;i++)
{
for(j=0;j<col;j++)
{
y=row*j+i;
if(y==0)
out[x]+=res*in[y]*(cos(((M_PI)*(j)*(v+1./2.))/n));
else
out[x]+=ress*in[y]*(cos(((M_PI)*(j)*(v+1./2.))/n));
}
}
}
}
}
else
{
for(u=0;u<row;u++)
{
for(v=0;v<col;v++)
{
x=v*row+u;
out[x]=0;
for(i=0;i<row;i++)
{
re=0;
for(j=0;j<col;j++)
{
y=row*j+i;
m=(float)in[j*row+i];
z=(float)(((float)v+1.0/2.0)*(float)j);
q=(float)(M_PI/(float)col);
m=m*(cos(q*z));
if(j==0)
re+=m/sqrt((float)col);
else
re+=m*sqrt(2./col);
}
z=(float)(((float)u+1.0/2.0)*(float)i);
q=(float)(M_PI/(float)row);
if(i==0)
out[x]+=(re*(cos(z*q)))/sqrt((float)row);
else
out[x]+=(re*(cos(z*q))*sqrt(2./row));
}
}
}
}
}
}
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