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Diffstat (limited to 'jni/feature_stab/db_vlvm/db_image_homography.cpp')
-rw-r--r-- | jni/feature_stab/db_vlvm/db_image_homography.cpp | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/jni/feature_stab/db_vlvm/db_image_homography.cpp b/jni/feature_stab/db_vlvm/db_image_homography.cpp new file mode 100644 index 000000000..aaad7f85e --- /dev/null +++ b/jni/feature_stab/db_vlvm/db_image_homography.cpp @@ -0,0 +1,332 @@ +/* + * Copyright (C) 2011 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* $Id: db_image_homography.cpp,v 1.2 2011/06/17 14:03:31 mbansal Exp $ */ + +#include "db_utilities.h" +#include "db_image_homography.h" +#include "db_framestitching.h" +#include "db_metrics.h" + + + +/***************************************************************** +* Lean and mean begins here * +*****************************************************************/ + +/*Compute the linear constraint on H obtained by requiring that the +ratio between coordinate i_num and i_den of xp is equal to the ratio +between coordinate i_num and i_den of Hx. i_zero should be set to +the coordinate not equal to i_num or i_den. No normalization is used*/ +inline void db_SProjImagePointPointConstraint(double c[9],int i_num,int i_den,int i_zero, + double xp[3],double x[3]) +{ + db_MultiplyScalarCopy3(c+3*i_den,x, xp[i_num]); + db_MultiplyScalarCopy3(c+3*i_num,x, -xp[i_den]); + db_Zero3(c+3*i_zero); +} + +/*Compute two constraints on H generated by the correspondence (Xp,X), +assuming that Xp ~= H*X. No normalization is used*/ +inline void db_SProjImagePointPointConstraints(double c1[9],double c2[9],double xp[3],double x[3]) +{ + int ma_ind; + + /*Find index of coordinate of Xp with largest absolute value*/ + ma_ind=db_MaxAbsIndex3(xp); + + /*Generate 2 constraints, + each constraint is generated by considering the ratio between a + coordinate and the largest absolute value coordinate*/ + switch(ma_ind) + { + case 0: + db_SProjImagePointPointConstraint(c1,1,0,2,xp,x); + db_SProjImagePointPointConstraint(c2,2,0,1,xp,x); + break; + case 1: + db_SProjImagePointPointConstraint(c1,0,1,2,xp,x); + db_SProjImagePointPointConstraint(c2,2,1,0,xp,x); + break; + default: + db_SProjImagePointPointConstraint(c1,0,2,1,xp,x); + db_SProjImagePointPointConstraint(c2,1,2,0,xp,x); + } +} + +inline void db_SAffineImagePointPointConstraints(double c1[7],double c2[7],double xp[3],double x[3]) +{ + double ct1[9],ct2[9]; + + db_SProjImagePointPointConstraints(ct1,ct2,xp,x); + db_Copy6(c1,ct1); c1[6]=ct1[8]; + db_Copy6(c2,ct2); c2[6]=ct2[8]; +} + +void db_StitchProjective2D_4Points(double H[9], + double x1[3],double x2[3],double x3[3],double x4[3], + double xp1[3],double xp2[3],double xp3[3],double xp4[3]) +{ + double c[72]; + + /*Collect the constraints*/ + db_SProjImagePointPointConstraints(c ,c+9 ,xp1,x1); + db_SProjImagePointPointConstraints(c+18,c+27,xp2,x2); + db_SProjImagePointPointConstraints(c+36,c+45,xp3,x3); + db_SProjImagePointPointConstraints(c+54,c+63,xp4,x4); + /*Solve for the nullvector*/ + db_NullVector8x9Destructive(H,c); +} + +void db_StitchAffine2D_3Points(double H[9], + double x1[3],double x2[3],double x3[3], + double xp1[3],double xp2[3],double xp3[3]) +{ + double c[42]; + + /*Collect the constraints*/ + db_SAffineImagePointPointConstraints(c ,c+7 ,xp1,x1); + db_SAffineImagePointPointConstraints(c+14,c+21,xp2,x2); + db_SAffineImagePointPointConstraints(c+28,c+35,xp3,x3); + /*Solve for the nullvector*/ + db_NullVector6x7Destructive(H,c); + db_MultiplyScalar6(H,db_SafeReciprocal(H[6])); + H[6]=H[7]=0; H[8]=1.0; +} + +/*Compute up to three solutions for the focal length given two point correspondences +generated by a rotation with a common unknown focal length. No specific normalization +of the input points is required. If signed_disambiguation is true, the points are +required to be in front of the camera*/ +inline void db_CommonFocalLengthFromRotation_2Point(double fsol[3],int *nr_sols,double x1[3],double x2[3],double xp1[3],double xp2[3],int signed_disambiguation=1) +{ + double m,ax,ay,apx,apy,bx,by,bpx,bpy; + double p1[2],p2[2],p3[2],p4[2],p5[2],p6[2]; + double p7[3],p8[4],p9[5],p10[3],p11[4]; + double roots[3]; + int nr_roots,i,j; + + /*Solve for focal length using the equation + <a,b>^2*<ap,ap><bp,bp>=<ap,bp>^2*<a,a><b,b> + where a and ap are the homogenous vectors in the first image + after focal length scaling and b,bp are the vectors in the + second image*/ + + /*Normalize homogenous coordinates so that last coordinate is one*/ + m=db_SafeReciprocal(x1[2]); + ax=x1[0]*m; + ay=x1[1]*m; + m=db_SafeReciprocal(xp1[2]); + apx=xp1[0]*m; + apy=xp1[1]*m; + m=db_SafeReciprocal(x2[2]); + bx=x2[0]*m; + by=x2[1]*m; + m=db_SafeReciprocal(xp2[2]); + bpx=xp2[0]*m; + bpy=xp2[1]*m; + + /*Compute cubic in l=1/(f^2) + by dividing out the root l=0 from the equation + (l(ax*bx+ay*by)+1)^2*(l(apx^2+apy^2)+1)*(l(bpx^2+bpy^2)+1)= + (l(apx*bpx+apy*bpy)+1)^2*(l(ax^2+ay^2)+1)*(l(bx^2+by^2)+1)*/ + p1[1]=ax*bx+ay*by; + p2[1]=db_sqr(apx)+db_sqr(apy); + p3[1]=db_sqr(bpx)+db_sqr(bpy); + p4[1]=apx*bpx+apy*bpy; + p5[1]=db_sqr(ax)+db_sqr(ay); + p6[1]=db_sqr(bx)+db_sqr(by); + p1[0]=p2[0]=p3[0]=p4[0]=p5[0]=p6[0]=1; + + db_MultiplyPoly1_1(p7,p1,p1); + db_MultiplyPoly1_2(p8,p2,p7); + db_MultiplyPoly1_3(p9,p3,p8); + + db_MultiplyPoly1_1(p10,p4,p4); + db_MultiplyPoly1_2(p11,p5,p10); + db_SubtractPolyProduct1_3(p9,p6,p11); + /*Cubic starts at p9[1]*/ + db_SolveCubic(roots,&nr_roots,p9[4],p9[3],p9[2],p9[1]); + + for(j=0,i=0;i<nr_roots;i++) + { + if(roots[i]>0) + { + if((!signed_disambiguation) || (db_PolyEval1(p1,roots[i])*db_PolyEval1(p4,roots[i])>0)) + { + fsol[j++]=db_SafeSqrtReciprocal(roots[i]); + } + } + } + *nr_sols=j; +} + +int db_StitchRotationCommonFocalLength_3Points(double H[9],double x1[3],double x2[3],double x3[3],double xp1[3],double xp2[3],double xp3[3],double *f,int signed_disambiguation) +{ + double fsol[3]; + int nr_sols,i,best_sol,done; + double cost,best_cost; + double m,hyp[27],x1_temp[3],x2_temp[3],xp1_temp[3],xp2_temp[3]; + double *hyp_point,ft; + double y[2]; + + db_CommonFocalLengthFromRotation_2Point(fsol,&nr_sols,x1,x2,xp1,xp2,signed_disambiguation); + if(nr_sols) + { + db_DeHomogenizeImagePoint(y,xp3); + done=0; + for(i=0;i<nr_sols;i++) + { + ft=fsol[i]; + m=db_SafeReciprocal(ft); + x1_temp[0]=x1[0]*m; + x1_temp[1]=x1[1]*m; + x1_temp[2]=x1[2]; + x2_temp[0]=x2[0]*m; + x2_temp[1]=x2[1]*m; + x2_temp[2]=x2[2]; + xp1_temp[0]=xp1[0]*m; + xp1_temp[1]=xp1[1]*m; + xp1_temp[2]=xp1[2]; + xp2_temp[0]=xp2[0]*m; + xp2_temp[1]=xp2[1]*m; + xp2_temp[2]=xp2[2]; + + hyp_point=hyp+9*i; + db_StitchCameraRotation_2Points(hyp_point,x1_temp,x2_temp,xp1_temp,xp2_temp); + hyp_point[2]*=ft; + hyp_point[5]*=ft; + hyp_point[6]*=m; + hyp_point[7]*=m; + cost=db_SquaredReprojectionErrorHomography(y,hyp_point,x3); + + if(!done || cost<best_cost) + { + done=1; + best_cost=cost; + best_sol=i; + } + } + + if(f) *f=fsol[best_sol]; + db_Copy9(H,hyp+9*best_sol); + return(1); + } + else + { + db_Identity3x3(H); + if(f) *f=1.0; + return(0); + } +} + +void db_StitchSimilarity2DRaw(double *scale,double R[4],double t[2], + double **Xp,double **X,int nr_points,int orientation_preserving, + int allow_scaling,int allow_rotation,int allow_translation) +{ + int i; + double c[2],cp[2],r[2],rp[2],M[4],s,sp,sc; + double *temp,*temp_p; + double Aacc,Bacc,Aacc2,Bacc2,divisor,divisor2,m,Am,Bm; + + if(allow_translation) + { + db_PointCentroid2D(c,X,nr_points); + db_PointCentroid2D(cp,Xp,nr_points); + } + else + { + db_Zero2(c); + db_Zero2(cp); + } + + db_Zero4(M); + s=sp=0; + for(i=0;i<nr_points;i++) + { + temp= *X++; + temp_p= *Xp++; + r[0]=(*temp++)-c[0]; + r[1]=(*temp++)-c[1]; + rp[0]=(*temp_p++)-cp[0]; + rp[1]=(*temp_p++)-cp[1]; + + M[0]+=r[0]*rp[0]; + M[1]+=r[0]*rp[1]; + M[2]+=r[1]*rp[0]; + M[3]+=r[1]*rp[1]; + + s+=db_sqr(r[0])+db_sqr(r[1]); + sp+=db_sqr(rp[0])+db_sqr(rp[1]); + } + + /*Compute scale*/ + if(allow_scaling) sc=sqrt(db_SafeDivision(sp,s)); + else sc=1.0; + *scale=sc; + + /*Compute rotation*/ + if(allow_rotation) + { + /*orientation preserving*/ + Aacc=M[0]+M[3]; + Bacc=M[2]-M[1]; + /*orientation reversing*/ + Aacc2=M[0]-M[3]; + Bacc2=M[2]+M[1]; + if(Aacc!=0.0 || Bacc!=0.0) + { + divisor=sqrt(Aacc*Aacc+Bacc*Bacc); + m=db_SafeReciprocal(divisor); + Am=Aacc*m; + Bm=Bacc*m; + R[0]= Am; + R[1]= Bm; + R[2]= -Bm; + R[3]= Am; + } + else + { + db_Identity2x2(R); + divisor=0.0; + } + if(!orientation_preserving && (Aacc2!=0.0 || Bacc2!=0.0)) + { + divisor2=sqrt(Aacc2*Aacc2+Bacc2*Bacc2); + if(divisor2>divisor) + { + m=db_SafeReciprocal(divisor2); + Am=Aacc2*m; + Bm=Bacc2*m; + R[0]= Am; + R[1]= Bm; + R[2]= Bm; + R[3]= -Am; + } + } + } + else db_Identity2x2(R); + + /*Compute translation*/ + if(allow_translation) + { + t[0]=cp[0]-sc*(R[0]*c[0]+R[1]*c[1]); + t[1]=cp[1]-sc*(R[2]*c[0]+R[3]*c[1]); + } + else db_Zero2(t); +} + + |