#include "mrilib.h" /************************************************************************/ /******* Hack to remove large spikes from time series data (oog). *******/ /******* 30 Aug 2002 - RWCox *******/ /************************************************************************/ #define TFAC 0.1 /* scale factor for -ssave dataset */ #define ITFAC 10.0 /* inverse of above */ /*----------------------------------------------------------------------*/ static INLINE float mytanh( float x ) { register float ex , exi ; if( x > 7.0 ) return 1.0 ; /* 03 Sep: check for stupid inputs */ else if( x < -7.0 ) return -1.0 ; ex = exp(x) ; exi = 1.0/ex ; return (ex-exi)/(ex+exi) ; } /*----------------------------------------------------------------------*/ int main( int argc , char * argv[] ) { THD_3dim_dataset *dset , *oset=NULL , *tset=NULL ; int nvals , iv , nxyz , ii,jj,kk , iarg , kz,kzold ; float cut1=2.5,cut2=4.0 , sq2p , fq , val , fsig ; MRI_IMAGE *flim ; float *far, *dar , *var , *fitar ; char *prefix="despike" , *tprefix=NULL ; int corder=-1 , nref , ignore=0 , polort=2 , nuse , nomask=0 ; int nspike, nbig, nproc ; float **ref ; float *fit , *ssp , snew , c21,ic21 , pspike,pbig , cls ; short *sar , *qar ; byte *tar , *mask=NULL ; float *zar , *yar ; int datum ; int localedit=0 , id,iu ; /* 04 Apr 2007 */ int verb=1 ; /*----- Read command line -----*/ if( argc < 2 || strcmp(argv[1],"-help") == 0 ){ printf("Usage: 3dDespike [options] dataset\n" "Removes 'spikes' from the 3D+time input dataset and writes\n" "a new dataset with the spike values replaced by something\n" "more pleasing to the eye.\n" "\n" "Method:\n" " * L1 fit a smooth-ish curve to each voxel time series\n" " [see -corder option for description of the curve].\n" " * Compute the MAD of the difference between the curve and\n" " the data time series (the residuals).\n" " * Estimate the standard deviation 'sigma' of the residuals\n" " as sqrt(PI/2)*MAD.\n" " * For each voxel value, define s = (value-curve)/sigma.\n" " * Values with s > c1 are replaced with a value that yields\n" " a modified s' = c1+(c2-c1)*tanh((s-c1)/(c2-c1)).\n" " * c1 is the threshold value of s for a 'spike' [default c1=2.5].\n" " * c2 is the upper range of the allowed deviation from the curve:\n" " s=[c1..infinity) is mapped to s'=[c1..c2) [default c2=4].\n" "\n" "Options:\n" " -ignore I = Ignore the first I points in the time series:\n" " these values will just be copied to the\n" " output dataset [default I=0].\n" " -corder L = Set the curve fit order to L:\n" " the curve that is fit to voxel data v(t) is\n" "\n" " k=L [ (2*PI*k*t) (2*PI*k*t) ]\n" " f(t) = a+b*t+c*t*t + SUM [ d * sin(--------) + e * cos(--------) ]\n" " k=1 [ k ( T ) k ( T ) ]\n" "\n" " where T = duration of time series;\n" " the a,b,c,d,e parameters are chosen to minimize\n" " the sum over t of |v(t)-f(t)| (L1 regression);\n" " this type of fitting is is insensitive to large\n" " spikes in the data. The default value of L is\n" " NT/30, where NT = number of time points.\n" "\n" " -cut c1 c2 = Alter default values for the spike cut values\n" " [default c1=2.5, c2=4.0].\n" " -prefix pp = Save de-spiked dataset with prefix 'pp'\n" " [default pp='despike']\n" " -ssave ttt = Save 'spikiness' measure s for each voxel into a\n" " 3D+time dataset with prefix 'ttt' [default=no save]\n" " -nomask = Process all voxels\n" " [default=use a mask of high-intensity voxels, ]\n" " [as created via '3dAutomask -dilate 4 dataset'].\n" " -q[uiet] = Don't print '++' informational messages.\n" "\n" " -localedit = Change the editing process to the following:\n" " If a voxel |s| value is >= c2, then replace\n" " the voxel value with the average of the two\n" " nearest non-spike (|s| < c2) values; the first\n" " one previous and the first one after.\n" " Note that the c1 cut value is not used here.\n" "\n" "Caveats:\n" "* Despiking may interfere with image registration, since head\n" " movement may produce 'spikes' at the edge of the brain, and\n" " this information would be used in the registration process.\n" " This possibility has not been explored or calibrated.\n" "* Check your data visually before and after despiking and\n" " registration!\n" " [Hint: open 2 AFNI controllers, and turn Time Lock on.]\n" ) ; exit(0) ; } /** AFNI package setup and logging **/ mainENTRY("3dDespike main"); machdep(); AFNI_logger("3dDespike",argc,argv); PRINT_VERSION("3dDespike") ; AUTHOR("RW Cox") ; /** parse options **/ iarg = 1 ; while( iarg < argc && argv[iarg][0] == '-' ){ if( strncmp(argv[iarg],"-q",2) == 0 ){ /* 04 Apr 2007 */ verb = 0 ; iarg++ ; continue ; } if( strncmp(argv[iarg],"-v",2) == 0 ){ verb++ ; iarg++ ; continue ; } /** -localedit **/ if( strcmp(argv[iarg],"-localedit") == 0 ){ /* 04 Apr 2007 */ localedit = 1 ; iarg++ ; continue ; } /** don't use masking **/ if( strcmp(argv[iarg],"-nomask") == 0 ){ nomask = 1 ; iarg++ ; continue ; } /** output dataset prefix **/ if( strcmp(argv[iarg],"-prefix") == 0 ){ prefix = argv[++iarg] ; if( !THD_filename_ok(prefix) ) ERROR_exit("-prefix is not good"); iarg++ ; continue ; } /** ratio dataset prefix **/ if( strcmp(argv[iarg],"-ssave") == 0 ){ tprefix = argv[++iarg] ; if( !THD_filename_ok(tprefix) ) ERROR_exit("-ssave prefix is not good"); iarg++ ; continue ; } /** trigonometric polynomial order **/ if( strcmp(argv[iarg],"-corder") == 0 ){ corder = strtol( argv[++iarg] , NULL , 10 ) ; if( corder < 0 ) ERROR_exit("Illegal value of -corder"); iarg++ ; continue ; } /** how much to ignore at start **/ if( strcmp(argv[iarg],"-ignore") == 0 ){ ignore = strtol( argv[++iarg] , NULL , 10 ) ; if( ignore < 0 ) ERROR_exit("Illegal value of -ignore"); iarg++ ; continue ; } /** thresholds for s ratio **/ if( strcmp(argv[iarg],"-cut") == 0 ){ cut1 = strtod( argv[++iarg] , NULL ) ; cut2 = strtod( argv[++iarg] , NULL ) ; if( cut1 < 1.0 || cut2 < cut1+0.5 ) ERROR_exit("Illegal values after -cut"); iarg++ ; continue ; } ERROR_exit("Unknown option: %s",argv[iarg]) ; } c21 = cut2-cut1 ; ic21 = 1.0/c21 ; /*----- read input dataset -----*/ if( iarg >= argc ) ERROR_exit("No input dataset!!??"); dset = THD_open_dataset( argv[iarg] ) ; CHECK_OPEN_ERROR(dset,argv[iarg]) ; datum = DSET_BRICK_TYPE(dset,0) ; if( (datum != MRI_short && datum != MRI_float) || !DSET_datum_constant(dset) ) ERROR_exit("Can't process non-short, non-float dataset!") ; if( verb ) INFO_message("Input data type = %s\n",MRI_TYPE_name[datum]) ; nvals = DSET_NUM_TIMES(dset) ; nuse = nvals - ignore ; if( nuse < 15 ) ERROR_exit("Can't use dataset with < 15 time points per voxel!") ; if( verb ) INFO_message("ignoring first %d time points, using last %d",ignore,nuse); if( corder > 0 && 4*corder+2 > nuse ){ ERROR_exit("-corder %d is too big for NT=%d",corder,nvals) ; } else if( corder < 0 ){ corder = rint(nuse/30.0) ; if( verb ) INFO_message("using %d time points => -corder %d",nuse,corder) ; } else { if( verb ) INFO_message("-corder %d set from command line",corder) ; } nxyz = DSET_NVOX(dset) ; if( verb ) INFO_message("Loading dataset %s",argv[iarg]) ; DSET_load(dset) ; CHECK_LOAD_ERROR(dset) ; /*-- create automask --*/ if( !nomask ){ mask = THD_automask( dset ) ; for( ii=0 ; ii < 4 ; ii++ ) THD_mask_dilate( DSET_NX(dset), DSET_NY(dset), DSET_NZ(dset), mask, 3 ) ; ii = THD_countmask( DSET_NVOX(dset) , mask ) ; if( verb ) INFO_message("%d voxels in the mask [out of %d in dataset]",ii,DSET_NVOX(dset)) ; } else { if( verb ) INFO_message("processing all %d voxels in dataset",DSET_NVOX(dset)) ; } /*-- create empty despiked dataset --*/ oset = EDIT_empty_copy( dset ) ; EDIT_dset_items( oset , ADN_prefix , prefix , ADN_brick_fac , NULL , ADN_datum_all , datum , ADN_none ) ; if( THD_deathcon() && THD_is_file(DSET_HEADNAME(oset)) ) ERROR_exit("output dataset already exists: %s",DSET_HEADNAME(oset)); tross_Copy_History( oset , dset ) ; tross_Make_History( "3dDespike" , argc , argv , oset ) ; /* create bricks (will be filled with zeros) */ for( iv=0 ; iv < nvals ; iv++ ) EDIT_substitute_brick( oset , iv , datum , NULL ) ; /* copy the ignored bricks */ switch( datum ){ case MRI_short: for( iv=0 ; iv < ignore ; iv++ ){ sar = DSET_ARRAY(oset,iv) ; qar = DSET_ARRAY(dset,iv) ; memcpy( sar , qar , DSET_BRICK_BYTES(dset,iv) ) ; DSET_unload_one(dset,iv) ; } break ; case MRI_float: for( iv=0 ; iv < ignore ; iv++ ){ zar = DSET_ARRAY(oset,iv) ; yar = DSET_ARRAY(dset,iv) ; memcpy( zar , yar , DSET_BRICK_BYTES(dset,iv) ) ; DSET_unload_one(dset,iv) ; } break ; } /*-- setup to save a threshold statistic dataset, if desired --*/ if( tprefix != NULL ){ float *fac ; tset = EDIT_empty_copy( dset ) ; fac = (float *) malloc( sizeof(float) * nvals ) ; for( ii=0 ; ii < nvals ; ii++ ) fac[ii] = TFAC ; EDIT_dset_items( tset , ADN_prefix , tprefix , ADN_brick_fac , fac , ADN_datum_all , MRI_byte , ADN_func_type , FUNC_FIM_TYPE , ADN_none ) ; free(fac) ; tross_Copy_History( tset , dset ) ; tross_Make_History( "3dDespike" , argc , argv , tset ) ; #if 0 if( THD_is_file(DSET_HEADNAME(tset)) ) ERROR_exit("-ssave dataset already exists"); #endif tross_Copy_History( tset , dset ) ; tross_Make_History( "3dDespike" , argc , argv , tset ) ; for( iv=0 ; iv < nvals ; iv++ ) EDIT_substitute_brick( tset , iv , MRI_byte , NULL ) ; } /*-- setup to find spikes --*/ sq2p = sqrt(0.5*PI) ; var = (float *) malloc( sizeof(float) * nvals ) ; far = (float *) malloc( sizeof(float) * nvals ) ; dar = (float *) malloc( sizeof(float) * nvals ) ; fitar = (float *) malloc( sizeof(float) * nvals ) ; ssp = (float *) malloc( sizeof(float) * nvals ) ; /* make ref functions */ nref = 2*corder+3 ; ref = (float **) malloc( sizeof(float *) * nref ) ; for( jj=0 ; jj < nref ; jj++ ) ref[jj] = (float *) malloc( sizeof(float) * nuse ) ; fit = (float *) malloc( sizeof(float) * nref ) ; /* r(t) = 1 */ for( iv=0 ; iv < nuse ; iv++ ) ref[0][iv] = 1.0 ; jj = 1 ; /* r(t) = t - tmid */ { float tm = 0.5 * (nuse-1.0) ; float fac = 2.0 / nuse ; for( iv=0 ; iv < nuse ; iv++ ) ref[1][iv] = (iv-tm)*fac ; jj = 2 ; /* r(t) = (t-tmid)**jj */ for( ; jj <= polort ; jj++ ) for( iv=0 ; iv < nuse ; iv++ ) ref[jj][iv] = pow( (iv-tm)*fac , (double)jj ) ; } for( kk=1 ; kk <= corder ; kk++ ){ fq = (2.0*PI*kk)/nuse ; /* r(t) = sin(2*PI*k*t/N) */ for( iv=0 ; iv < nuse ; iv++ ) ref[jj][iv] = sin(fq*iv) ; jj++ ; /* r(t) = cos(2*PI*k*t/N) */ for( iv=0 ; iv < nuse ; iv++ ) ref[jj][iv] = cos(fq*iv) ; jj++ ; } /*--- loop over voxels and do work ---*/ if( verb ){ if( !localedit ){ INFO_message("smash edit thresholds: %.1f .. %.1f standard deviations",cut1,cut2) ; INFO_message(" [ %.4f%% .. %.4f%% of normal distribution]", 200.0*qg(cut1) , 200.0*qg(cut2) ) ; } else { INFO_message("local edit threshold: %.1f standard deviations",cut2) ; INFO_message(" [ %.4f%% of normal distribution]", 200.0*qg(cut2) ) ; } INFO_message("%d slices to process",DSET_NZ(dset)) ; } kzold = -1 ; nspike = 0 ; nbig = 0 ; nproc = 0 ; for( ii=0 ; ii < nxyz ; ii++ ){ /* ii = voxel index */ if( mask != NULL && mask[ii] == 0 ) continue ; /* skip this voxel */ kz = DSET_index_to_kz(dset,ii) ; /* starting a new slice */ if( kz != kzold ){ if( verb ){ fprintf(stderr, "++ start slice %2d",kz ) ; if( nproc > 0 ){ pspike = (100.0*nspike)/nproc ; pbig = (100.0*nbig )/nproc ; fprintf(stderr, "; so far %d data points, %d edits [%.3f%%], %d big edits [%.3f%%]", nproc,nspike,pspike,nbig,pbig ) ; } fprintf(stderr,"\n") ; } kzold = kz ; } /*** extract ii-th time series into far[] ***/ switch( datum ){ case MRI_short: for( iv=0 ; iv < nuse ; iv++ ){ qar = DSET_ARRAY(dset,iv+ignore) ; /* skip ignored data */ far[iv] = (float) qar[ii] ; } break ; case MRI_float: for( iv=0 ; iv < nuse ; iv++ ){ zar = DSET_ARRAY(dset,iv+ignore) ; far[iv] = zar[ii] ; } break ; } memcpy(dar,far,sizeof(float)*nuse) ; /* copy time series into dar[] */ /*** solve for L1 fit ***/ cls = cl1_solve( nuse , nref , far , ref , fit,0 ) ; /* the slow part */ if( cls < 0.0 ){ /* fit failed! */ #if 0 fprintf(stderr,"curve fit fails at voxel %d %d %d\n", DSET_index_to_ix(dset,ii) , DSET_index_to_jy(dset,ii) , DSET_index_to_kz(dset,ii) ) ; #endif continue ; /* skip this voxel */ } for( iv=0 ; iv < nuse ; iv++ ){ /* detrend */ val = fit[0] + fit[1]*ref[1][iv] /* quadratic part of curve fit */ + fit[2]*ref[2][iv] ; for( jj=3 ; jj < nref ; jj++ ) /* rest of curve fit */ val += fit[jj] * ref[jj][iv] ; fitar[iv] = val ; /* save curve fit value */ var[iv] = dar[iv]-val ; /* remove fitted value = resid */ far[iv] = fabs(var[iv]) ; /* abs value of resid */ } /*** compute estimate standard deviation of detrended data ***/ fsig = sq2p * qmed_float(nuse,far) ; /* also mangles far array */ /*** process time series for spikes, editing data in dar[] ***/ if( fsig > 0.0 ){ /* data wasn't fit perfectly */ /* find spikiness for each point in time */ fq = 1.0 / fsig ; for( iv=0 ; iv < nuse ; iv++ ){ ssp[iv] = fq * var[iv] ; /* spikiness s = how many sigma out */ } /* save spikiness in -ssave datset */ if( tset != NULL ){ for( iv=0 ; iv < nuse ; iv++ ){ tar = DSET_ARRAY(tset,iv+ignore) ; snew = ITFAC*fabs(ssp[iv]) ; /* scale for byte storage */ tar[ii] = BYTEIZE(snew) ; /* cf. mrilib.h */ } } /* process values of |s| > cut1, editing dar[] */ for( iv=0 ; iv < nuse ; iv++ ){ /* loop over time points */ if( !localedit ){ /** classic 'smash' edit **/ if( ssp[iv] > cut1 ){ snew = cut1 + c21*mytanh((ssp[iv]-cut1)*ic21) ; /* edit s down */ dar[iv] = fitar[iv] + snew*fsig ; nspike++ ; if( ssp[iv] > cut2 ) nbig++ ; /* count edits */ } else if( ssp[iv] < -cut1 ){ snew = -cut1 + c21*mytanh((ssp[iv]+cut1)*ic21) ; /* edit s up */ dar[iv] = fitar[iv] + snew*fsig ; nspike++ ; if( ssp[iv] < -cut2 ) nbig++ ; } } else { /** local edit: 04 Apr 2007 **/ if( ssp[iv] >= cut2 || ssp[iv] <= -cut2 ){ for( iu=iv+1 ; iu < nuse ; iu++ ) /* find non-spike above */ if( ssp[iu] < cut2 && ssp[iu] > -cut2 ) break ; for( id=iv-1 ; id >= 0 ; id-- ) /* find non-spike below */ if( ssp[id] < cut2 && ssp[id] > -cut2 ) break ; switch( (id>=0) + 2*(iu 0 ){ pspike = (100.0*nspike)/nproc ; pbig = (100.0*nbig )/nproc ; INFO_message("FINAL: %d data points, %d edits [%.3f%%], %d big edits [%.3f%%]", nproc,nspike,pspike,nbig,pbig ) ; } else { INFO_message("FINAL: no good voxels found to process!!??") ; } } /* write results */ DSET_write(oset) ; if( verb ) WROTE_DSET(oset) ; DSET_delete(oset) ; if( tset != NULL ){ DSET_write(tset) ; if( verb ) WROTE_DSET(tset) ; DSET_delete(tset) ; } exit(0) ; }