// CFA pixel cleaning via directional average // © Emil Martinec // 2/18/2010 #define TS 256 // Tile size #include #include #include #define SQR(x) ((x)*(x)) //void green_equilibrate()//for dcraw implementation void RawImageSource::green_equilibrate(float thresh) { // local variables static const int border=8; static const int border2=16; static const int v1=TS, v2=2*TS, v3=3*TS, /*v4=4*TS,*/ p1=-TS+1, p2=-2*TS+2, p3=-3*TS+3, m1=TS+1, m2=2*TS+2, m3=3*TS+3; int height=H, width=W; //for RT only int top, left; int verbose=1; static const float eps=1.0; //tolerance to avoid dividing by zero //static const float thresh=0.03; //threshold for performing green equilibration; max percentage difference of G1 vs G2 // G1-G2 differences larger than this will be assumed to be Nyquist texture, and left untouched static const float diffthresh=0.25; //threshold for texture, not to be equilibrated /*double dt; clock_t t1, t2; //clock_t t1_main, t2_main = 0; // start if (verbose) fprintf (stderr,_("Green equilibration ...\n")); t1 = clock();*/ // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% // Fill G interpolated values with border interpolation and input values // Main algorithm: Tile loop //#pragma omp parallel for shared(image,height,width) private(top,left) schedule(dynamic) for (top=0; top < height-border; top += TS-border2) for (left=0; left < width-border; left += TS-border2) { int bottom = MIN( top+TS,height); int right = MIN(left+TS, width); int numrows = bottom - top; int numcols = right - left; int row, col; int rr, cc, c, indx; int vote1, vote2; float val1; float gin, gse, gsw, gne, gnw, wtse, wtsw, wtne, wtnw; float gu, gd, gl, gr; float mcorr, pcorr; float ginterp; float diffvarh, diffvarv, hvwt; char *buffer; // TS*TS*16 float (*cfa); // TS*TS*4 float (*checker); // TS*TS*4 float (*gvar); // TS*TS*4 float (*gdiffv); // TS*TS*4 float (*gdiffh); // TS*TS*4 /* assign working space */ buffer = (char *) malloc(5*sizeof(float)*TS*TS); //merror(buffer,"green_equil()"); memset(buffer,0,5*sizeof(float)*TS*TS); cfa = (float (*)) buffer; checker = (float (*)) (buffer + sizeof(float)*TS*TS); gvar = (float (*)) (buffer + 2*sizeof(float)*TS*TS); gdiffv = (float (*)) (buffer + 3*sizeof(float)*TS*TS); gdiffh = (float (*)) (buffer + 4*sizeof(float)*TS*TS); /*float cfa[TS*TS]; float checker[TS*TS]; //this memory allocation crashes RT float gvar[TS*TS]; memset( (void *)&cfa[0], 0 ,sizeof(cfa) );*/ // rgb from input CFA data /* rgb values should be floating point number between 0 and 1 after white balance multipliers are applied */ for (rr=0; rr < numrows; rr++) for (row=rr+top, cc=0; cc < numcols; cc++) { col = cc+left; //cfa[rr*TS+cc] = image[row*width+col][FC(row,col)];//for dcraw implementation cfa[rr*TS+cc] = rawData[row][col]; } //The green equilibration algorithm starts here for (rr=2; rr < numrows-2; rr++) //for (cc=3-(FC(rr,2)&1), indx=rr*TS+cc; cc < numcols-2; cc+=2, indx+=2) { for (indx=rr*TS+2; indx < rr*TS+numcols-2; indx++) { if (FC(rr,indx)&1) { pcorr = (cfa[indx+p1]-cfa[indx])*(cfa[indx-p1]-cfa[indx]); mcorr = (cfa[indx+m1]-cfa[indx])*(cfa[indx-m1]-cfa[indx]); if (pcorr>0 && mcorr>0) {checker[indx]=1;} else {checker[indx]=0;} //checker[indx]=1;//test what happens if we always interpolate } else { gu=cfa[indx-v1]+0.5*(cfa[indx]-cfa[indx-v2]); gd=cfa[indx+v1]+0.5*(cfa[indx]-cfa[indx+v2]); gl=cfa[indx-1]+0.5*(cfa[indx]-cfa[indx-2]); gr=cfa[indx+1]+0.5*(cfa[indx]-cfa[indx+2]); gdiffh[indx] = SQR((gl-gr)/(eps+gl+gr)); gdiffv[indx] = SQR((gu-gd)/(eps+gu+gd)); //gvar[indx] = 0.25*(gu*gu+gd*gd+gl*gl+gr*gr)-SQR(0.25*(gu+gd+gl+gr)); } } //now smooth the cfa data for (rr=6; rr < numrows-6; rr++) for (cc=7-(FC(rr,2)&1), indx=rr*TS+cc; cc < numcols-6; cc+=2, indx+=2) { if (checker[indx]) { diffvarh = eps+(gdiffh[indx-v1]+gdiffh[indx-1]+gdiffh[indx+1]+gdiffh[indx+v1]); diffvarv = eps+(gdiffv[indx-v1]+gdiffv[indx-1]+gdiffv[indx+1]+gdiffv[indx+v1]); hvwt = fabs(diffvarv-diffvarh)/(diffvarv+diffvarh); vote1=(checker[indx-v2]+checker[indx-2]+checker[indx+2]+checker[indx+v2]); vote2=(checker[indx-m1]+checker[indx+p1]+checker[indx-p1]+checker[indx+m1]); if (vote1>0 && vote2>0 && hvwt 0.125*(gvar[indx-1]+gvar[indx+1]+gvar[indx-v1]+gvar[indx+v1])) &&*/ ((ginterp-gin) < thresh*(ginterp+gin)) ) { cfa[indx]=0.5*(ginterp+gin); } } } } // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% // copy smoothed results back to image matrix for (rr=border; rr < numrows-border; rr++) for (row=rr+top, cc=border+1-(FC(rr,2)&1), indx=rr*TS+cc; cc < numcols-border; cc+=2, indx+=2) { if (cfa[indx]<1) continue; col = cc + left; //c = FC(row,col); //image[row*width + col][c] = CLIP((int)(cfa[indx] + 0.5)); //for dcraw implementation rawData[row][col] = CLIP((int)(cfa[indx] + 0.5)); } // clean up free(buffer); } // done /*t2 = clock(); dt = ((double)(t2-t1)) / CLOCKS_PER_SEC; if (verbose) { fprintf(stderr,_("elapsed time = %5.3fs\n"),dt); }*/ } #undef TS