📄 cxdxt.cpp
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double t1 = -dst[i+1].im;
dst[i].im = (float)t0;
dst[i+1].im = (float)t1;
}
if( i < n0 )
dst[n0-1].im = -dst[n0-1].im;
}
return CV_OK;
}
/* FFT of real vector
output vector format:
re(0), re(1), im(1), ... , re(n/2-1), im((n+1)/2-1) [, re((n+1)/2)] OR ...
re(0), 0, re(1), im(1), ..., re(n/2-1), im((n+1)/2-1) [, re((n+1)/2), 0] */
#define ICV_REAL_DFT( flavor, datatype ) \
static CvStatus CV_STDCALL \
icvRealDFT_##flavor( const datatype* src, datatype* dst, \
int n, int nf, int* factors, const int* itab, \
const CvComplex##flavor* wave, int tab_size, \
const void* spec, CvComplex##flavor* buf, \
int flags, double scale ) \
{ \
int complex_output = (flags & ICV_DFT_COMPLEX_INPUT_OR_OUTPUT) != 0;\
int j, n2 = n >> 1; \
dst += complex_output; \
\
if( spec ) \
{ \
icvDFTFwd_RToPack_##flavor##_p( src, dst, spec, buf ); \
goto finalize; \
} \
\
assert( tab_size == n ); \
\
if( n == 1 ) \
{ \
dst[0] = (datatype)(src[0]*scale); \
} \
else if( n == 2 ) \
{ \
double t = (src[0] + src[1])*scale; \
dst[1] = (datatype)((src[0] - src[1])*scale); \
dst[0] = (datatype)t; \
} \
else if( n & 1 ) \
{ \
dst -= complex_output; \
CvComplex##flavor* _dst = (CvComplex##flavor*)dst; \
_dst[0].re = (datatype)(src[0]*scale); \
_dst[0].im = 0; \
for( j = 1; j < n; j += 2 ) \
{ \
double t0 = src[itab[j]]*scale; \
double t1 = src[itab[j+1]]*scale; \
_dst[j].re = (datatype)t0; \
_dst[j].im = 0; \
_dst[j+1].re = (datatype)t1; \
_dst[j+1].im = 0; \
} \
icvDFT_##flavor##c( _dst, _dst, n, nf, factors, itab, wave, \
tab_size, 0, buf, ICV_DFT_NO_PERMUTE, 1. ); \
if( !complex_output ) \
dst[1] = dst[0]; \
return CV_OK; \
} \
else \
{ \
double t0, t; \
double h1_re, h1_im, h2_re, h2_im; \
double scale2 = scale*0.5; \
factors[0] >>= 1; \
\
icvDFT_##flavor##c( (CvComplex##flavor*)src, \
(CvComplex##flavor*)dst, n2, \
nf - (factors[0] == 1), \
factors + (factors[0] == 1), \
itab, wave, tab_size, 0, buf, 0, 1. ); \
factors[0] <<= 1; \
\
t = dst[0] - dst[1]; \
dst[0] = (datatype)((dst[0] + dst[1])*scale); \
dst[1] = (datatype)(t*scale); \
\
t0 = dst[n2]; \
t = dst[n-1]; \
dst[n-1] = dst[1]; \
\
for( j = 2, wave++; j < n2; j += 2, wave++ ) \
{ \
/* calc odd */ \
h2_re = scale2*(dst[j+1] + t); \
h2_im = scale2*(dst[n-j] - dst[j]); \
\
/* calc even */ \
h1_re = scale2*(dst[j] + dst[n-j]); \
h1_im = scale2*(dst[j+1] - t); \
\
/* rotate */ \
t = h2_re*wave->re - h2_im*wave->im; \
h2_im = h2_re*wave->im + h2_im*wave->re; \
h2_re = t; \
t = dst[n-j-1]; \
\
dst[j-1] = (datatype)(h1_re + h2_re); \
dst[n-j-1] = (datatype)(h1_re - h2_re); \
dst[j] = (datatype)(h1_im + h2_im); \
dst[n-j] = (datatype)(h2_im - h1_im); \
} \
\
if( j <= n2 ) \
{ \
dst[n2-1] = (datatype)(t0*scale); \
dst[n2] = (datatype)(-t*scale); \
} \
} \
\
finalize: \
if( complex_output ) \
{ \
dst[-1] = dst[0]; \
dst[0] = 0; \
if( (n & 1) == 0 ) \
dst[n] = 0; \
} \
\
return CV_OK; \
}
/* Inverse FFT of complex conjugate-symmetric vector
input vector format:
re[0], re[1], im[1], ... , re[n/2-1], im[n/2-1], re[n/2] OR
re(0), 0, re(1), im(1), ..., re(n/2-1), im((n+1)/2-1) [, re((n+1)/2), 0] */
#define ICV_CCS_IDFT( flavor, datatype ) \
static CvStatus CV_STDCALL \
icvCCSIDFT_##flavor( const datatype* src, datatype* dst, \
int n, int nf, int* factors, const int* itab, \
const CvComplex##flavor* wave, int tab_size, \
const void* spec, CvComplex##flavor* buf, \
int flags, double scale ) \
{ \
int complex_input = (flags & ICV_DFT_COMPLEX_INPUT_OR_OUTPUT) != 0; \
int j, k, n2 = (n+1) >> 1; \
double save_s1 = 0.; \
double t0, t1, t2, t3, t; \
\
assert( tab_size == n ); \
\
if( complex_input ) \
{ \
assert( src != dst ); \
save_s1 = src[1]; \
((datatype*)src)[1] = src[0]; \
src++; \
} \
\
if( spec ) \
{ \
icvDFTInv_PackToR_##flavor##_p( src, dst, spec, buf ); \
goto finalize; \
} \
\
if( n == 1 ) \
{ \
dst[0] = (datatype)(src[0]*scale); \
} \
else if( n == 2 ) \
{ \
t = (src[0] + src[1])*scale; \
dst[1] = (datatype)((src[0] - src[1])*scale); \
dst[0] = (datatype)t; \
} \
else if( n & 1 ) \
{ \
CvComplex##flavor* _src = (CvComplex##flavor*)(src-1); \
CvComplex##flavor* _dst = (CvComplex##flavor*)dst; \
\
_dst[0].re = src[0]; \
_dst[0].im = 0; \
for( j = 1; j < n2; j++ ) \
{ \
int k0 = itab[j], k1 = itab[n-j]; \
t0 = _src[j].re; t1 = _src[j].im; \
_dst[k0].re = (datatype)t0; _dst[k0].im = (datatype)-t1; \
_dst[k1].re = (datatype)t0; _dst[k1].im = (datatype)t1; \
} \
\
icvDFT_##flavor##c( _dst, _dst, n, nf, factors, itab, wave, \
tab_size, 0, buf, ICV_DFT_NO_PERMUTE, 1. ); \
dst[0] = (datatype)(dst[0]*scale); \
for( j = 1; j < n; j += 2 ) \
{ \
t0 = dst[j*2]*scale; \
t1 = dst[j*2+2]*scale; \
dst[j] = (datatype)t0; \
dst[j+1] = (datatype)t1; \
} \
} \
else \
{ \
int inplace = src == dst; \
const CvComplex##flavor* w = wave; \
\
t = src[1]; \
t0 = (src[0] + src[n-1]); \
t1 = (src[n-1] - src[0]); \
dst[0] = (datatype)t0; \
dst[1] = (datatype)t1; \
\
for( j = 2, w++; j < n2; j += 2, w++ ) \
{ \
double h1_re, h1_im, h2_re, h2_im; \
\
h1_re = (t + src[n-j-1]); \
h1_im = (src[j] - src[n-j]); \
\
h2_re = (t - src[n-j-1]); \
h2_im = (src[j] + src[n-j]); \
\
t = h2_re*w->re + h2_im*w->im; \
h2_im = h2_im*w->re - h2_re*w->im; \
h2_re = t; \
\
t = src[j+1]; \
t0 = h1_re - h2_im; \
t1 = -h1_im - h2_re; \
t2 = h1_re + h2_im; \
t3 = h1_im - h2_re; \
\
if( inplace ) \
{ \
dst[j] = (datatype)t0; \
dst[j+1] = (datatype)t1; \
dst[n-j] = (datatype)t2; \
dst[n-j+1]= (datatype)t3; \
} \
else \
{ \
int j2 = j >> 1; \
k = itab[j2]; \
dst[k] = (datatype)t0; \
dst[k+1] = (datatype)t1; \
k = itab[n2-j2]; \
dst[k] = (datatype)t2; \
dst[k+1]= (datatype)t3; \
} \
} \
\
if( j <= n2 ) \
{ \
t0 = t*2; \
t1 = src[n2]*2; \
\
if( inplace ) \
{ \
dst[n2] = (datatype)t0; \
dst[n2+1] = (datatype)t1; \
} \
else \
{ \
k = itab[n2]; \
dst[k*2] = (datatype)t0; \
dst[k*2+1] = (datatype)t1; \
} \
} \
\
factors[0] >>= 1; \
icvDFT_##flavor##c( (CvComplex##flavor*)dst, \
(CvComplex##flavor*)dst, n2, \
nf - (factors[0] == 1), \
factors + (factors[0] == 1), itab, \
wave, tab_size, 0, buf, \
inplace ? 0 : ICV_DFT_NO_PERMUTE, 1. ); \
factors[0] <<= 1; \
\
for( j = 0; j < n; j += 2 ) \
{ \
t0 = dst[j]*scale; \
t1 = dst[j+1]*(-scale); \
dst[j] = (datatype)t0; \
dst[j+1] = (datatype)t1; \
} \
} \
\
finalize: \
if( complex_input ) \
((datatype*)src)[0] = (datatype)save_s1; \
\
return CV_OK; \
}
ICV_REAL_DFT( 64f, double )
ICV_CCS_IDFT( 64f, double )
ICV_REAL_DFT( 32f, float )
ICV_CCS_IDFT( 32f, float )
static void
icvCopyColumn( const uchar* _src, int src_step,
uchar* _dst, int dst_step,
int len, int elem_size )
{
int i, t0, t1;
const int* src = (const int*)_src;
int* dst = (int*)_dst;
src_step /= sizeof(src[0]);
dst_step /= sizeof(dst[0]⌨️ 快捷键说明
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