-
Notifications
You must be signed in to change notification settings - Fork 1
/
imResampleMex.cpp
170 lines (164 loc) · 7.63 KB
/
imResampleMex.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
/*******************************************************************************
* Piotr's Computer Vision Matlab Toolbox Version 3.00
* Copyright 2014 Piotr Dollar. [pdollar-at-gmail.com]
* Licensed under the Simplified BSD License [see external/bsd.txt]
*******************************************************************************/
#include "wrappers.hpp"
#include "string.h"
#include <math.h>
#include <typeinfo>
#include "sse.hpp"
typedef unsigned char uchar;
// compute interpolation values for single column for resapling
template<class T> void resampleCoef( int ha, int hb, int &n, int *&yas,
int *&ybs, T *&wts, int bd[2], int pad=0 )
{
const T s = T(hb)/T(ha), sInv = 1/s; T wt, wt0=T(1e-3)*s;
bool ds=ha>hb; int nMax; bd[0]=bd[1]=0;
if(ds) { n=0; nMax=ha+(pad>2 ? pad : 2)*hb; } else { n=nMax=hb; }
// initialize memory
wts = (T*)alMalloc(nMax*sizeof(T),16);
yas = (int*)alMalloc(nMax*sizeof(int),16);
ybs = (int*)alMalloc(nMax*sizeof(int),16);
if( ds ) for( int yb=0; yb<hb; yb++ ) {
// create coefficients for downsampling
T ya0f=yb*sInv, ya1f=ya0f+sInv, W=0;
int ya0=int(ceil(ya0f)), ya1=int(ya1f), n1=0;
for( int ya=ya0-1; ya<ya1+1; ya++ ) {
wt=s; if(ya==ya0-1) wt=(ya0-ya0f)*s; else if(ya==ya1) wt=(ya1f-ya1)*s;
if(wt>wt0 && ya>=0) { ybs[n]=yb; yas[n]=ya; wts[n]=wt; n++; n1++; W+=wt; }
}
if(W>1) for( int i=0; i<n1; i++ ) wts[n-n1+i]/=W;
if(n1>bd[0]) bd[0]=n1;
while( n1<pad ) { ybs[n]=yb; yas[n]=yas[n-1]; wts[n]=0; n++; n1++; }
} else for( int yb=0; yb<hb; yb++ ) {
// create coefficients for upsampling
T yaf = (T(.5)+yb)*sInv-T(.5); int ya=(int) floor(yaf);
wt=1; if(ya>=0 && ya<ha-1) wt=1-(yaf-ya);
if(ya<0) { ya=0; bd[0]++; } if(ya>=ha-1) { ya=ha-1; bd[1]++; }
ybs[yb]=yb; yas[yb]=ya; wts[yb]=wt;
}
}
// resample A using bilinear interpolation and and store result in B
template<class T>
void resample( T *A, T *B, int ha, int hb, int wa, int wb, int d, T r ) {
int hn, wn, x, x1, y, z, xa, xb, ya; T *A0, *A1, *A2, *A3, *B0, wt, wt1;
T *C = (T*) alMalloc((ha+4)*sizeof(T),16); for(y=ha; y<ha+4; y++) C[y]=0;
bool sse = (typeid(T)==typeid(float)) && !(size_t(A)&15) && !(size_t(B)&15);
// get coefficients for resampling along w and h
int *xas, *xbs, *yas, *ybs; T *xwts, *ywts; int xbd[2], ybd[2];
resampleCoef<T>( wa, wb, wn, xas, xbs, xwts, xbd, 0 );
resampleCoef<T>( ha, hb, hn, yas, ybs, ywts, ybd, 4 );
if( wa==2*wb ) r/=2; if( wa==3*wb ) r/=3; if( wa==4*wb ) r/=4;
r/=T(1+1e-6); for( y=0; y<hn; y++ ) ywts[y] *= r;
// resample each channel in turn
for( z=0; z<d; z++ ) for( x=0; x<wb; x++ ) {
if(x==0) x1=0; xa=xas[x1]; xb=xbs[x1]; wt=xwts[x1]; wt1=1-wt; y=0;
A0=A+z*ha*wa+xa*ha; A1=A0+ha, A2=A1+ha, A3=A2+ha; B0=B+z*hb*wb+xb*hb;
// variables for SSE (simple casts to float)
float *Af0, *Af1, *Af2, *Af3, *Bf0, *Cf, *ywtsf, wtf, wt1f;
Af0=(float*) A0; Af1=(float*) A1; Af2=(float*) A2; Af3=(float*) A3;
Bf0=(float*) B0; Cf=(float*) C;
ywtsf=(float*) ywts; wtf=(float) wt; wt1f=(float) wt1;
// resample along x direction (A -> C)
#define FORs(X) if(sse) for(; y<ha-4; y+=4) STR(Cf[y],X);
#define FORr(X) for(; y<ha; y++) C[y] = X;
if( wa==2*wb ) {
FORs( ADD(LDu(Af0[y]),LDu(Af1[y])) );
FORr( A0[y]+A1[y] ); x1+=2;
} else if( wa==3*wb ) {
FORs( ADD(LDu(Af0[y]),LDu(Af1[y]),LDu(Af2[y])) );
FORr( A0[y]+A1[y]+A2[y] ); x1+=3;
} else if( wa==4*wb ) {
FORs( ADD(LDu(Af0[y]),LDu(Af1[y]),LDu(Af2[y]),LDu(Af3[y])) );
FORr( A0[y]+A1[y]+A2[y]+A3[y] ); x1+=4;
} else if( wa>wb ) {
int m=1; while( x1+m<wn && xb==xbs[x1+m] ) m++; float wtsf[4];
for( int x0=0; x0<(m<4?m:4); x0++ ) wtsf[x0]=float(xwts[x1+x0]);
#define U(x) MUL( LDu(*(Af ## x + y)), SET(wtsf[x]) )
#define V(x) *(A ## x + y) * xwts[x1+x]
if(m==1) { FORs(U(0)); FORr(V(0)); }
if(m==2) { FORs(ADD(U(0),U(1))); FORr(V(0)+V(1)); }
if(m==3) { FORs(ADD(U(0),U(1),U(2))); FORr(V(0)+V(1)+V(2)); }
if(m>=4) { FORs(ADD(U(0),U(1),U(2),U(3))); FORr(V(0)+V(1)+V(2)+V(3)); }
#undef U
#undef V
for( int x0=4; x0<m; x0++ ) {
A1=A0+x0*ha; wt1=xwts[x1+x0]; Af1=(float*) A1; wt1f=float(wt1); y=0;
FORs(ADD(LD(Cf[y]),MUL(LDu(Af1[y]),SET(wt1f)))); FORr(C[y]+A1[y]*wt1);
}
x1+=m;
} else {
bool xBd = x<xbd[0] || x>=wb-xbd[1]; x1++;
if(xBd) memcpy(C,A0,ha*sizeof(T));
if(!xBd) FORs(ADD(MUL(LDu(Af0[y]),SET(wtf)),MUL(LDu(Af1[y]),SET(wt1f))));
if(!xBd) FORr( A0[y]*wt + A1[y]*wt1 );
}
#undef FORs
#undef FORr
// resample along y direction (B -> C)
if( ha==hb*2 ) {
T r2 = r/2; int k=((~((size_t) B0) + 1) & 15)/4; y=0;
for( ; y<k; y++ ) B0[y]=(C[2*y]+C[2*y+1])*r2;
if(sse) for(; y<hb-4; y+=4) STR(Bf0[y],MUL((float)r2,_mm_shuffle_ps(ADD(
LDu(Cf[2*y]),LDu(Cf[2*y+1])),ADD(LDu(Cf[2*y+4]),LDu(Cf[2*y+5])),136)));
for( ; y<hb; y++ ) B0[y]=(C[2*y]+C[2*y+1])*r2;
} else if( ha==hb*3 ) {
for(y=0; y<hb; y++) B0[y]=(C[3*y]+C[3*y+1]+C[3*y+2])*(r/3);
} else if( ha==hb*4 ) {
for(y=0; y<hb; y++) B0[y]=(C[4*y]+C[4*y+1]+C[4*y+2]+C[4*y+3])*(r/4);
} else if( ha>hb ) {
y=0;
//if( sse && ybd[0]<=4 ) for(; y<hb; y++) // Requires SSE4
// STR1(Bf0[y],_mm_dp_ps(LDu(Cf[yas[y*4]]),LDu(ywtsf[y*4]),0xF1));
#define U(o) C[ya+o]*ywts[y*4+o]
if(ybd[0]==2) for(; y<hb; y++) { ya=yas[y*4]; B0[y]=U(0)+U(1); }
if(ybd[0]==3) for(; y<hb; y++) { ya=yas[y*4]; B0[y]=U(0)+U(1)+U(2); }
if(ybd[0]==4) for(; y<hb; y++) { ya=yas[y*4]; B0[y]=U(0)+U(1)+U(2)+U(3); }
if(ybd[0]>4) for(; y<hn; y++) { B0[ybs[y]] += C[yas[y]] * ywts[y]; }
#undef U
} else {
for(y=0; y<ybd[0]; y++) B0[y] = C[yas[y]]*ywts[y];
for(; y<hb-ybd[1]; y++) B0[y] = C[yas[y]]*ywts[y]+C[yas[y]+1]*(r-ywts[y]);
for(; y<hb; y++) B0[y] = C[yas[y]]*ywts[y];
}
}
alFree(xas); alFree(xbs); alFree(xwts); alFree(C);
alFree(yas); alFree(ybs); alFree(ywts);
}
// B = imResampleMex(A,hb,wb,nrm); see imResample.m for usage details
#ifdef MATLAB_MEX_FILE
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[]) {
int *ns, ms[3], n, m, nCh, nDims;
void *A, *B; mxClassID id; double nrm;
// Error checking on arguments
if( nrhs!=4) mexErrMsgTxt("Four inputs expected.");
if( nlhs>1 ) mexErrMsgTxt("One output expected.");
nDims=mxGetNumberOfDimensions(prhs[0]); id=mxGetClassID(prhs[0]);
ns = (int*) mxGetDimensions(prhs[0]); nCh=(nDims==2) ? 1 : ns[2];
if( (nDims!=2 && nDims!=3) ||
(id!=mxSINGLE_CLASS && id!=mxDOUBLE_CLASS && id!=mxUINT8_CLASS) )
mexErrMsgTxt("A should be 2D or 3D single, double or uint8 array.");
ms[0]=(int)mxGetScalar(prhs[1]); ms[1]=(int)mxGetScalar(prhs[2]); ms[2]=nCh;
if( ms[0]<=0 || ms[1]<=0 ) mexErrMsgTxt("downsampling factor too small.");
nrm=(double)mxGetScalar(prhs[3]);
// create output array
plhs[0] = mxCreateNumericArray(3, (const mwSize*) ms, id, mxREAL);
n=ns[0]*ns[1]*nCh; m=ms[0]*ms[1]*nCh;
// perform resampling (w appropriate type)
A=mxGetData(prhs[0]); B=mxGetData(plhs[0]);
if( id==mxDOUBLE_CLASS ) {
resample((double*)A, (double*)B, ns[0], ms[0], ns[1], ms[1], nCh, nrm);
} else if( id==mxSINGLE_CLASS ) {
resample((float*)A, (float*)B, ns[0], ms[0], ns[1], ms[1], nCh, float(nrm));
} else if( id==mxUINT8_CLASS ) {
float *A1 = (float*) mxMalloc(n*sizeof(float));
float *B1 = (float*) mxCalloc(m,sizeof(float));
for(int i=0; i<n; i++) A1[i]=(float) ((uchar*)A)[i];
resample(A1, B1, ns[0], ms[0], ns[1], ms[1], nCh, float(nrm));
for(int i=0; i<m; i++) ((uchar*)B)[i]=(uchar) (B1[i]+.5);
} else {
mexErrMsgTxt("Unsupported type.");
}
}
#endif