Francesca Tosi and Alberto Mancini presented benchmarks comparing the performance of grayscale conversion in various environments on Android, including Java, C using the NDK, Intel IPP, and JavaScript. They tested processing 1024x1024 pixel images on a Galaxy Tab 3 with an Intel Atom CPU. Results showed that C using NDK and Intel IPP significantly outperformed Java and JavaScript implementations.

1. Intel NDK x86
A few Benchmarks
Francesca Tosi - Alberto Mancini
13 Febbraio 2013

2. ?!?
● Ma che ci fanno
Alberto e
Francesca!??!?!

3. ?!?
● Ma che ci fanno
Alberto e
Francesca!??!?!
● Ma non erano quelli
fissati con le app
web!??!?!

4. Intel
Francesco Baldassarri
Italian Community Manager
Intel Software and Services Group
email: francescoX.baldassarri@intel.com
twitter: @francesco_1985
facebook: www.facebook.com/francesco1985
linkedin: it.linkedin.com/in/fbaldassarri/

5. Intel Devices
I devices Intel sono compatibili con l’
ecosistema Android*.
- Android* Dalvik* apps
- These will directly work, Dalvik has beenoptimized for Intel® platforms.
- Android NDK apps
- Most will run without any recompilation on consumer platforms.
- Android NDK provides an x86 toolchain since 2011
- A simple recompile using the Android NDK yields the best performance
- If there is specific processor dependent code, porting may be necessary

6. Intel Devices
Intel Investe molto in tool di sviluppo per
Android
- Faster Android Emulator on Intel (Intel HAXM)
- Intel Threading Building Blocks (TBB)
- Intel Graphics Performance Analyzer (GPA)
- Intel Integrated Performance Primitives (IPP)
- Intel Optimizing Compiler (C++)
- Intel Beacon Mountain
- Project Anarchy

7. Intel Devices
Cosa sta facendo intel per Android

8. Intel Devices
Intel devices on the market with Intel Inside

9. Librerie native
3rd party Libraries with x86 support

10. ???
Ma voi due che c’
entrate con le app
native !?!?

11. NDK
A noi interessa sperimentare la
rapidità/potenzialità della NDK
App NDK
Applicazione
Android
che usa
librerie native

12. Benchmarks
e testarne le performance
Benchmark
C/Java/Javascript

13. AR on mobile
Nei lavori che facciamo una
operazione semplice ma costosa
è fare il grayscale sulle immagini
picshare.jooink.com

14. GWT-Boofcv
GWT-Boofcv sample at:
http://goo.gl/3IJQgs

15. Benchmarks
-

16. Test arena
Galaxy Tab3
Intel Atom CPU Z2560
2 core - 1.60 GHz
Android 4.4.2
Architettura i686

17. Rules
1
2
3
RGB
jbyte[1024*1024*3]
gray
jbyte[1024*1024]
0.299*R+0.587*G+0.114*B → Y
Average on 1000 runs

18. Competitors
Benchmarks on:
Chrome <Uint8Array>
Firefox <Uint8Array>
Aurora <Uint8Array>
Java
<byte>
NDK
<jbyte>
IPP
<Ipp8u>

19. Details (HAXM)
Bundled in BeaconMountain
http://software.intel.com/en-us/android/articles/intel-hardwareaccelerated-execution-manager
Attenzione pianta OSX, maverick
installare lo hotfix
cambia la vita con le immagini x86

20. Codice (Java)
Java:
void compute(byte[] in, byte[] out) {
for(int i=0, j=0; i< out.length; i++, j+=3)
out[i] =
(byte)(0.299 * in[j] + 0.587 * in[j+1] + 0.114 * in[j+2]);
}

21. Details (NDK)
https://developer.android.com/tools/sdk/ndk/index.html
La documentazione non e’ il suo forte ...
https://github.com/jooink/ndk-cpuid
●
●
●
●
start the (intel) avd (url)
enter in the jni folder & execute 'ndk-build'
from the CPUIDApp root dir execute 'ant debug'
adb install -r bin/CPUIdApp-debug.apk

22. Codice (C, jni)
void JNICALL … jbyteArray in, jbyteArray out) {
jsize len_out = (*env)->GetArrayLength(env, out);
...
jbyte *body_out = (*env)->GetByteArrayElements(env, out, 0);
for(i=0, j=0; i< len_out; i++, j+=3)
body_out[i] = (jbyte)(0.299 * body_in[j] + … );
(*env)->ReleaseByteArrayElements(env, in, body_in, 0);
...
}

23. Details (IPP)
Bundled in BeaconMountain
beh … la ‘preview’
http://software.intel.com/en-us/intel-ipp
Scaricate la versione per linux ( la evaluation, or 199$ :( )
Installatela ( vi serve una macchina linux )
Copiate le librerie (*.a) e gli include (*.h)
(32bit statici non-threaded)
… ed avete la IPP per android x86 !!!

24. Codice (IPP)
… jni ...
IppiSize srcRoi = { 1024, 1024 };
Ipp8u* pSrc = body_in;
Ipp8u* pDst = body_out;
ippiRGBToGray_8u_C3C1R(pSrc ,1024, pDst, 1024, srcRoi);
… jni ...

25. Results native

26. Results native
min
max
avg

27. Codice (js)
var len_out = outb.length;
var i,j;
for(i=0, j=0; i< len_out; i++, j+=3)
outb[i] = (0.299 * inb[j] + 0.587 * inb[j+1] + 0.114 *inb[j+2]);
var buffer_in = new ArrayBuffer(size*3);
var buffer_out = new ArrayBuffer(size);
var inb = new Uint8Array(buffer_in);
var out = new Uint8Array(buffer_out);

28. Results js
min
max
avg

29. Grazie
Francesca Tosi
francesca@jooink.com
Alberto Mancini
alberto@jooink.com
Github: github.com/jooink/
www.jooink.com
jooink.blogspot.com