test_random.cpp is not cross-platform about cvblob HOT 12 CLOSED

I didn't realize that that was not portable :-S

In the other hand, I have an issue with `clock()`. In the test it always 
returns:

{{{
40 miliseconds elapsed.
30 miliseconds elapsed.
40 miliseconds elapsed.
40 miliseconds elapsed.
40 miliseconds elapsed.
30 miliseconds elapsed.
...
}}}

But with my previous implementation it returns:

{{{
37 miliseconds elapsed.
43 miliseconds elapsed.
36 miliseconds elapsed.
40 miliseconds elapsed.
38 miliseconds elapsed.
36 miliseconds elapsed.
39 miliseconds elapsed.
36 miliseconds elapsed.
...
}}}

I don't know if that is a problem with precision of `clock()` or my 
`gettimeofday()` is giving me some trash. Can you tell me what kind of values 
you watch with your implementation?

In any case I could use `#ifdef WIN32` if necessary.

Thank you very much for your help!!

It seems you're loosing precision. Try doing the multiplication first:

double elapsedTime = double (t2 - t1) * 1000.0 / CLOCKS_PER_SEC;

By the way, my elapsed times are huge! I'm getting the following values: 393, 
599, 867, 1094 and up to 1605, with an average of 1256.29 ms and 24 iterations.

I'll test the code in a linux virtual machine later in the day and I'll post 
here my results.

Same results ¿? :-S

Anyway, searching on Google I have reached to this:

{{{
#ifndef _WIN32

#include <sys/time.h>

#else

#include <windows.h>

int gettimeofday (struct timeval *tv, void* tz)
{
  union {
    long long ns100; /*time since 1 Jan 1601 in 100ns units */
    FILETIME ft;
  } now;

  GetSystemTimeAsFileTime (&now.ft);
  tv->tv_usec = (long) ((now.ns100 / 10LL) % 1000000LL);
  tv->tv_sec = (long) ((now.ns100 - 116444736000000000LL) / 10000000LL);
  return (0);
}

#endif
}}}

Can you test it in my version of `test_random.cpp` on Windows?

Thank you very much!

It seems that `clock()` returns how much CPU time the process has used, not how 
much wall-clock time has passed. And perhaps Linux gives 10 ms to each process, 
I don't know... In that case, `clock()` will have the "real" CPU time that 
`cvLabel` is using...

Also, the elapsed times you are getting are very high. What `size` and 
`numPixels` are you using?

PS: Are you spanish? Because I am :D

I found this page that compares clock() and gettimeofday() and even proposes 
something else, although I think their solution is Intel only : 
http://software.intel.com/en-us/articles/best-timing-function-for-measuring-ipp-
api-timing/

Anyway, I'll test your version later in the day and I'll tell you if it works.

I'm not Spanish, but you weren't that far. I'm Mexican :D.
What made you think I speak spanish ? :P

I've just tested your version in windows and it works!! (Still, I'm not very 
fund of macros). There's just a small bug : you forgot to add <ctime>.

I keep having the same huge elapsedTimes. I didn't change the default values : 
size = 500 and numPixels = 100000 and I'm pretty sure my computer is not that 
slow ...

Maybe my random method is too random ?? :P
Here are the results of my test :

Nb blobs : 9482 and 119230 pixels :: 387 miliseconds elapsed.
Nb blobs : 9583 and 119338 pixels :: 598 miliseconds elapsed.
Nb blobs : 9440 and 119402 pixels :: 1035 miliseconds elapsed.
Nb blobs : 9558 and 119129 pixels :: 1226 miliseconds elapsed.
Nb blobs : 9600 and 119559 pixels :: 1319 miliseconds elapsed.
Nb blobs : 9384 and 119468 pixels :: 999 miliseconds elapsed.
Nb blobs : 9478 and 119504 pixels :: 1213 miliseconds elapsed.
Nb blobs : 9614 and 119305 pixels :: 1278 miliseconds elapsed.
Nb blobs : 9386 and 119534 pixels :: 1029 miliseconds elapsed.
Nb blobs : 9738 and 119188 pixels :: 1458 miliseconds elapsed.
Nb blobs : 9519 and 119702 pixels :: 1250 miliseconds elapsed.

How many blobs are you getting ?

Hola de nuevo! Estuve de viaje, por eso no he respondido antes.

Adiviné que hablabas español porque además de informático soy mentalista ;D

Veo que te sigue yendo muy despacio el test_random ¿Estás compilando en 
"debug mode"? A lo mejor es eso :-S Esto es lo que me sale a mi:

[...]
 - 9557 blobs and 119213 pixels: 36 miliseconds elapsed.
 - 9411 blobs and 119597 pixels: 35 miliseconds elapsed.
 - 9441 blobs and 119608 pixels: 35 miliseconds elapsed.
 - 9540 blobs and 119652 pixels: 35 miliseconds elapsed.
 - 9472 blobs and 119326 pixels: 36 miliseconds elapsed.
 - 9535 blobs and 119281 pixels: 36 miliseconds elapsed.
 - 9515 blobs and 119498 pixels: 35 miliseconds elapsed.
 - 9368 blobs and 119214 pixels: 35 miliseconds elapsed.
 - 9549 blobs and 119231 pixels: 36 miliseconds elapsed.
 - 9489 blobs and 119149 pixels: 35 miliseconds elapsed.
 - 9556 blobs and 119362 pixels: 35 miliseconds elapsed.
 - 9586 blobs and 119903 pixels: 35 miliseconds elapsed.
 - 9311 blobs and 119940 pixels: 35 miliseconds elapsed.
 - 9456 blobs and 119338 pixels: 36 miliseconds elapsed.
 - 9370 blobs and 119644 pixels: 36 miliseconds elapsed.
 - 9452 blobs and 119756 pixels: 36 miliseconds elapsed.
 - 9468 blobs and 119692 pixels: 35 miliseconds elapsed.
 - 9657 blobs and 119720 pixels: 47 miliseconds elapsed.
 - 9446 blobs and 119642 pixels: 36 miliseconds elapsed.
 - 9342 blobs and 119417 pixels: 36 miliseconds elapsed.

100 iterations.
Average cvLabel time: 35.99 miliseconds.

Es muy raro que te vaya tan lento. Quizás sea el ordenador, yo uso un 
portátil con un Intel Core Duo a 1.73GHz.

Un saludo!

Creo que realmente eres mentalista porque si estaba compilando en debug mode ;).
Sin embargo compilando en release mode opencv y cvblob cambia muy poco el 
tiempo de ejecución. No creo que sea mi ordenador, uso un pc de escritorio con 
un Intel i7 a 2.67Ghz ...
Estas utilizando TBB ?
Y de nuevo felicidades por tu biblioteca esta bastante completa !

Listo, cambié de compilador ( a mingw ) y ahora el tiempo promedio es de 22 ms 
:D.
Creo que hay un problema con las optimizaciones de opencv y el compilador de 
visual studio.

Hola de nuevo,

Veo que hay problemas con Visual Studio :-S Me alegro de que funcione mejor con 
MinGW! He añadido al repositorio la solución para la portabilidad en el 
test_random.cpp y dentro de poco sacaré un nuevo paquete, así que voy a 
cerrar este "issue".

Muchas gracias por la ayuda!

I couldn't test your changes before, there's still a small bug : the #include 
should be either <ctime> or <time.h>

Otherwise it works perfectly !

BTW have you tried compiling your lib with the latest 2.2 opencv version ?

Fixed! Thanks again :D

I don't remember if I have compiled cvBlob using 2.2, 2.1 or both. I do know it 
works with 2.1 for sure.