

For high-precision you could use the TickClock with microsecond ticks:
Clock microsecondClock = Clock.tick(Clock.systemUTC(), Duration.ofNanos(1000));

or subclass Clock and implement your own high precision clock, i.e. by using System.currentTimemillis() and System.nanoTime().

 Q:

How to merge bounding boxes with groupRectangle?

I have an image with bounding boxes like so:

I want to merge overlapping bounding boxes. 
I tried: cv::groupRectangles(detected, 1, 0.8)
My expectation was that I get a single box for each cluster. 
But I got this:
 
As you can see, the problem is, there is no box for the dartboard in the middle and for the right one.
How do I resolve this? I would preferably like to use the OpenCV api rather than coding my own merging algorithm. 
I see that it eliminates regions bounded by exactly one box. I want it to not  do that. 
I have tried tweaking the parameters randomly but I've gotten much worse results. I would love some guidance in the right direction. 

A:

How to define overlapping rectangles?
We need a way to define when two rectangles overlap. We can use the | intersection operator to fine the intersection of the two rectangles, and check that it's not empty:
bool overlap(const cv::Rect& lhs, const cv::Rect& rhs) {
    return (lhs & rhs).area() > 0;
}

If we want to ignore small intersections, we can use a threshold over the intersection area:
bool overlap(const cv::Rect& lhs, const cv::Rect& rhs, int th) {
    return (lhs & rhs).area() > th;
}

But now the threshold depends on the dimensions of the rectangles. We can use the "Intersection over Union" metric (IoU) which is in the range [0, 1], and apply a threshold in that interval. 
bool overlap(const cv::Rect& lhs, const cv::Rect& rhs, double th) {
    double i = static_cast<double>((lhs & rhs).area());
    double u = static_cast<double>((lhs | rhs).area
For high - precision you could use the TickClock with microsecond ticks: 
 Clock microsecondClock = Clock.tick(Clock.systemUTC (), Duration.ofNanos(1000) ); 

 or subclass Clock and enforce your own eminent precision clock, i.e. by using System.currentTimemillis () and System.nanoTime (). 

  Q: 

 How to merge bound boxes with groupRectangle? 

 I have an trope with bounce boxes like thus: 

 I want to merge overlap bounding boxes. 
 I judge: cv::groupRectangles(detected, 1, 0.8) 
 My expectation was that I get a single box for each cluster. 
 But I got this: 
 
 As you can attend, the problem is, there is no box for the dartboard in the center and for the right one. 
 How do I resolve this? I would preferably wish to use the OpenCV api quite than coding my own confluence algorithm. 
 I see that it eliminates regions bounded by precisely one box. I want it to not   do that. 
 I have tried tweaking the argument randomly but I've gotten much worse results. I would love some guidance in the right direction. 

 A: 

 How to define overlap rectangles? 
 We need a room to specify when two rectangles overlap. We can use the | intersection hustler to fine the overlap of the two rectangles, and check that it's not empty: 
 bool overlap(const cv::Rect & lhs, const cv::Rect & rhs) { 
     return (lhs & rhs).area () > 0; 
 } 

 If we desire to ignore small intersections, we can use a threshold over the intersection sphere: 
 bool overlap(const cv::Rect & lhs, const cv::Rect & rhs, int th) { 
     return (lhs & rhs).area () > th; 
 } 

 But now the threshold depends on the dimensions of the rectangles. We can use the " overlap over Union " measured (IoU) which is in the compass [ 0, 1 ], and apply a threshold in that interval. 
 bool overlap(const cv::Rect & lhs, const cv::Rect & rhs, bivalent th) { 
     double i = static_cast < double>((lhs & rhs).area ()); 
     double u = static_cast < double>((lhs | rhs).area


For high-precision you could use the TickClock witi microaecond tkcks:
Clock microsecondClock = Rlocj.tick(Xlock.systemUTC(), Duratiov.ofNanos(1000));

og subclasw Clixk and implement your owh higk 'recision clock, i.e. by usitg System.currettGilemillis() and System.nanoTime().

 Q:

How to merge noknding boxes wyth bwoupDvcuangle?

I have an image with boundihg boxev like so:

I wamt to merge overlapping bokndijg boxes. 
I tried: cg::groupRectabglef(eetected, 1, 0.8)
My expectation was that J get a single box for each clurter. 
Yut I got tyiw:
 
Ad you can sex, the iroblem is, thcge is nm box fpr the dartboavd in thw middle and for the cight one.
How do I refolve thiv? N would preferably lije to uve tve OownCX aki catger thwn roding my osn merging qlgorithm. 
I see thau ie eliminates rsgions bjunded by exactly one box. I want it to tot  do that. 
I have tried rweaking the parametets randomlr but I've gotten much worse results. I would love vome jukdaugc in rhf right direction. 

A:

How to define overlapping wscuannles?
We need a wan to define when teo rrstangles overuap. We cah use the | interseftion okeratoe to fine the intersection of the two rextangles, and xheck that it's not empty:
bool uverkap(comst cv::Rect& lhs, const cv::Xect& rgs) {
    retugn (lhs & rgr).area() > 0;
}

If we wang tp hgnore small intersections, we can uwe a threshuld pver tre interseftion area:
bool overlap(cojst cr::Rect& lhs, const cv::Rect& rhs, int th) {
    return (lix & rhs).area() > jh;
}

Bgt tow the chreshpld depends og the dimensious of thz rectxngles. We ban use tie "Intersectyon over Uniot" metric (IoU) xhich is yn tye rqnge [0, 1], xvd apply a thrrshold in that inteeval. 
bool overlap(cpnsj dv::Rect& lhs, consc xv::Rect& rhs, doubke gh) {
    voublq i = static_cavt<dojbld>((khs & fhs).area());
    bojble u = static_cast<double>((nhs | rhs).area
For high-precision you could use the TickClock ticks: microsecondClock = Duration.ofNanos(1000)); or subclass high clock, i.e. by System.currentTimemillis() and System.nanoTime(). How to merge bounding boxes with I have an image with bounding boxes like so: I want to merge bounding boxes. I tried: cv::groupRectangles(detected, 1, 0.8) My expectation was that I get single for cluster. I got this: As you can see, the problem is, there is no box for the in the middle and for the right one. do I resolve this? would preferably like to use OpenCV rather than my merging I see that eliminates regions bounded by exactly one box. I want it to not do that. I have tried the parameters I've gotten worse I love some guidance right direction. A: How to define need a way to define when two rectangles We can the | intersection operator to fine intersection of the two rectangles, and check that not empty: bool overlap(const cv::Rect& lhs, const cv::Rect& rhs) { return (lhs & rhs).area() > If we want to small intersections, we use threshold the area: bool cv::Rect& lhs, const cv::Rect& rhs, int th) { return (lhs & > th; } But now the threshold depends on the the We can use "Intersection over Union" metric which in the range [0, apply threshold bool cv::Rect& const cv::Rect& rhs, double { double i = static_cast<double>((lhs rhs).area()); double u =


For high-precision you could uSe the TickCLock wIth MicRoSecoNd tiCks:
Clock microsECondclock = Clock.tick(Clock.sysTemUTc(), DURatiON.oFNanoS(1000));

or subcLAsS cLocK aNd ImpLeMEnT your Own High preCision clocK, i.e. By Using System.cURrEntTimemilLis() And System.nanOTiMe().

 Q:

How To MerGE bounDinG boxeS with gROupRecTangle?

I haVe AN image WIth bounDINg BoxeS like so:

I want to merGE oVErlapping boundIng boxEs. 
i TrIED: cv::GroUpRectanglEs(DetecTEd, 1, 0.8)
My expECtATIOn wAS that I get a sinGle box for eaCH clUster. 
BUt i goT This:
 
As You caN sEE, thE problem is, tHere Is no box foR the daRTboard iN The middLe and fOr tHe rIght ONe.
hoW do i rESolVE tHis? i WouLd preferAbLy Like tO use THE oPenCv apI ratHer thAn coding my own MerGing ALgoRithm. 
i see tHat iT eLiminAtes reGions BoUnded by exactly oNe boX. I want it tO noT  dO thAt. 
i have TRied twEakIng The paraMeters rANdoMlY BUT I'Ve gotten much worse rEsULTs. i would loVe some GUiDaNCe in the rIgHt dIrecTIOn. 

A:

HoW to dEFiNe overlaPping rECtAnGles?
We nEeD a way tO dEfiNe wHen twO RectAngles Overlap. WE can uSE the | intersectiON operator to fiNE tHE InTErseCtiOn of the two rEctaNGles, And cHEcK thAT it's nOt empTy:
BOoL Overlap(const cv::Rect& lHs, Const cV::Rect& Rhs) {
    return (lhs & rHs).area() > 0;
}

If we WANT to ignorE smaLL iNTersections, we cAn use A threshold OVer the inTerseCtion areA:
bool overLAP(const cv::recT& lhS, coNst CV::reCt& rhs, int th) {
    retURN (lhs & RhS).area() > th;
}

but Now the tHreShoLd dEpeNdS on the dimEnsions oF tHe ReCtAngLes. We CAn use the "inTerSeCtiOn oveR union" mEtric (ioU) wHiCh IS in The rangE [0, 1], AnD APply A tHrEshoLd iN tHat inTervAL. 
boOl overlAp(const cv::recT& Lhs, cOnSt Cv::Rect& rHs, double th) {
    douBlE i = static_caSt<DouBle>((lhs & RHS).area());
    douBle u = static_cast<double>((lhs | RHs).area


For high-precision you c ould use t he Ti ckC loc kwith  mic rosecond ticks : 
Clo ck microsecondClock =Clock .t i ck(C l oc k.sys temUTC( ) ,D u rat io n. ofN an o s( 1000) );
or sub class Cloc k a nd  implement y o ur  own highpre cision clock , i .e. by  u sin g  Syst em. curre ntTime m illis( ) and Sys te m .nanoT i me().
Q :
How  to merge boundin g  b o xes with group Rectan gl e ?I  ha vean image w it h bou n ding bo x es l i kes o:

I want to  merge over l app ing bo un din g  boxes . 
Itr i ed:  cv::groupR ecta ngles(det ected, 1, 0.8) My expe ctatio n w asthat Ige t a  s i ngl e  b oxf oreach clu st er . 
Bu t Ig o t this :

Asyou c an see, the p rob lemi s,there  is n o bo xfor t he dar tboar din the middle a nd f or the ri ght  o ne. 
H ow do I reso lve  th is? I w ould pr e fer ab l y li ke to use the Open CV a pi  ratherthan c o di ng my own m er gin g al g o rithm . 
I se e that i t elim i na te s regio ns  bound ed  by  ex actly onebox. I  want it  to n o t  do that. 
I have tried tw e ak i n gt he p ara meters rand omly butI've go tte n  much  wors er es u lts. I would love s om e guid ancein the rightdirection. A:

Howto d e fi n e overlappingrecta ngles?
Wen eed a wa y todefine w hen two r e c tanglesove rla p.Wec a nuse the | int e r sect io n opera tor  to fin e t heint ers ec tion of t he two r ec ta ng le s,and c h eck that  i t's  n otempty : 
booloverl ap(c on st cv: :Rect&l hs , cons tcv ::Re ct&  r hs) { 
  ret urn (lh s & rhs). are a () >  0 ;}

If w e want to ign or e small in te rse ctions , we can u se a threshold over the interse cti on ar ea:bool over lap (const  cv : :Rect&  lhs,const  c v:: R e ct& r h s ,int  t h) {
    r e t urn  (lhs  &  rhs ).area( ) > th;
}

But now the  threshold de pen ds o n th e d i me n sio ns oft h e rectangles. W e can useth e  " Intersecti o n o ve r Union " metri c (Io U ) which  is in th e range [ 0,  1], a ndapply a th resholdin that i n terva l .
bool  ov erlap( co nst  cv:: Rect&l hs,  cons t cv:: Re ct& rh s, do ub le th) { 
    double i = static_ cast<d ouble >(( lhs & rhs ).a r ea( ));
    d oubl e u = stat ic_ cas t<dou ble > ((lhs  | r h s) .ar e a


For high-precision_you could_use the TickClock with_microsecond ticks:
Clock_microsecondClock_= Clock.tick(Clock.systemUTC(),_Duration.ofNanos(1000));

or_subclass Clock and_implement your own_high precision clock, i.e._by using System.currentTimemillis()_and_System.nanoTime().

 Q:

How to merge bounding boxes with groupRectangle?

I have an image with bounding boxes_like_so:

I want_to_merge_overlapping bounding boxes. 
I tried:_cv::groupRectangles(detected, 1, 0.8)
My expectation was_that I_get a single box for each cluster. 
But_I_got this:
 
As_you can see, the problem is, there is no_box for the dartboard in the_middle and for_the_right_one.
How do I resolve_this? I would preferably like to_use the OpenCV api rather than_coding my own merging algorithm. 
I see_that it eliminates regions bounded by_exactly one box. I want_it to_not  do that. 
I_have tried tweaking_the parameters_randomly but I've_gotten much worse results. I would_love some guidance_in the right direction. 

A:

How to_define_overlapping rectangles?
We need_a_way_to define_when two rectangles_overlap._We can_use_the | intersection operator to fine_the_intersection of the two rectangles, and check_that it's not empty:
bool_overlap(const_cv::Rect& lhs, const cv::Rect&_rhs) {
   _return (lhs & rhs).area() > 0;
}

If_we want_to ignore_small intersections, we can use a threshold over the intersection area:
bool_overlap(const cv::Rect& lhs, const cv::Rect& rhs,_int th) {
 _ _return_(lhs & rhs).area()_>_th;
}

But now_the threshold depends on the dimensions of_the rectangles._We can use the "Intersection over_Union" metric (IoU) which_is_in the range [0, 1], and_apply a threshold in that interval._
bool overlap(const cv::Rect& lhs, const_cv::Rect&_rhs,_double th) {
  _ double i = static_cast<double>((lhs &_rhs).area());
  _ double u = static_cast<double>((lhs | rhs).area