diff options
Diffstat (limited to 'src/c/signalProcessing/transforms/dct/ddcta.c')
| -rw-r--r-- | src/c/signalProcessing/transforms/dct/ddcta.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/src/c/signalProcessing/transforms/dct/ddcta.c b/src/c/signalProcessing/transforms/dct/ddcta.c new file mode 100644 index 0000000..3802c81 --- /dev/null +++ b/src/c/signalProcessing/transforms/dct/ddcta.c @@ -0,0 +1,160 @@ +/* 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 ddcta(double *in,int row,int col,int sign,double *out) +{ + int i,j,k,u,v; + int n; + int x,y; + double res,ress; + double 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 + { + double 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=(double)in[j*row+i]; + z=(double)(((double)j+1.0/2.0)*(double)v); + q=(double)(M_PI/(double)col); + re+=m*(cos(q*z)); + } + z=(double)(((double)i+1.0/2.0)*(double)u); + q=(double)(M_PI/(double)row); + out[x]+=re*(cos(q*z)); + } + if(u==0) + { + out[x]/=sqrt((double)row); + if(v==0) + out[x]/=sqrt((double)col); + else + out[x]*=sqrt(2./col); + } + else + { + out[x]*=sqrt(2./row); + if(v==0) + out[x]/=sqrt((double)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=(double)in[j*row+i]; + z=(double)(((double)v+1.0/2.0)*(double)j); + q=(double)(M_PI/(double)col); + m=m*(cos(q*z)); + if(j==0) + re+=m/sqrt((double)col); + else + re+=m*sqrt(2./col); + } + z=(double)(((double)u+1.0/2.0)*(double)i); + q=(double)(M_PI/(double)row); + if(i==0) + out[x]+=(re*(cos(z*q)))/sqrt((double)row); + else + out[x]+=(re*(cos(z*q))*sqrt(2./row)); + } + } + } + } + } +} |