Thank you :). There's lots of issues to close first, and I think 0.98 would be more appropriate.
The API also needs big, breaking changes, to handle multi-image file formats, copy/rewrite metadata losslessly, and other things... Damjan On Thu, Oct 16, 2014 at 7:01 AM, Gary Gregory <garydgreg...@gmail.com> wrote: > Good to see you pop up! > > What are your thoughts on getting to 1.0? > > Gary > > ---------- Forwarded message ---------- > From: <dam...@apache.org> > Date: Thu, Oct 16, 2014 at 12:49 AM > Subject: svn commit: r1632210 - > /commons/proper/imaging/trunk/src/main/java/org/apache/commons/imaging/formats/jpeg/decoder/Dct.java > To: comm...@commons.apache.org > > > Author: damjan > Date: Thu Oct 16 04:49:30 2014 > New Revision: 1632210 > > URL: http://svn.apache.org/r1632210 > Log: > Format some comments better. > > > Modified: > > commons/proper/imaging/trunk/src/main/java/org/apache/commons/imaging/formats/jpeg/decoder/Dct.java > > Modified: > commons/proper/imaging/trunk/src/main/java/org/apache/commons/imaging/formats/jpeg/decoder/Dct.java > URL: > http://svn.apache.org/viewvc/commons/proper/imaging/trunk/src/main/java/org/apache/commons/imaging/formats/jpeg/decoder/Dct.java?rev=1632210&r1=1632209&r2=1632210&view=diff > ============================================================================== > --- > commons/proper/imaging/trunk/src/main/java/org/apache/commons/imaging/formats/jpeg/decoder/Dct.java > (original) > +++ > commons/proper/imaging/trunk/src/main/java/org/apache/commons/imaging/formats/jpeg/decoder/Dct.java > Thu Oct 16 04:49:30 2014 > @@ -22,10 +22,13 @@ final class Dct { > * Here's the cost, exluding modified (de)quantization, for > transforming an > * 8x8 block: > * > - * Algorithm Adds Multiplies RightShifts Total Naive 896 1024 0 1920 > - * "Symmetries" 448 224 0 672 Vetterli and 464 208 0 672 Ligtenberg > Arai, > - * Agui and 464 80 0 544 Nakajima (AA&N) Feig 8x8 462 54 6 522 Fused > mul/add > - * 416 (a pipe dream) > + * Algorithm Adds Multiplies RightShifts Total > + * Naive 896 1024 0 1920 > + * "Symmetries" 448 224 0 672 > + * Vetterli and Ligtenberg 464 208 0 672 > + * Arai, Agui and Nakajima (AA&N) 464 80 0 544 > + * Feig 8x8 462 54 6 522 > + * Fused mul/add (a pipe dream) 416 > * > * IJG's libjpeg, FFmpeg, and a number of others use AA&N. > * > @@ -33,21 +36,25 @@ final class Dct { > * are reduced from 80 in AA&N to only 54. But in practice: > * > * Benchmarks, Intel Core i3 @ 2.93 GHz in long mode, 4 GB RAM Time > taken to > - * do 100 million IDCTs (less is better): Rene' Stöckel's Feig, int: > 45.07 > - * seconds My Feig, floating point: 36.252 seconds AA&N, unrolled > loops, > - * double[][] -> double[][]: 25.167 seconds > + * do 100 million IDCTs (less is better): > + * Rene' Stöckel's Feig, int: 45.07 seconds > + * My Feig, floating point: 36.252 seconds > + * AA&N, unrolled loops, double[][] -> double[][]: 25.167 seconds > * > * Clearly Feig is hopeless. I suspect the performance killer is > simply the > * weight of the algorithm: massive number of local variables, large > code > * size, and lots of random array accesses. > * > - * Also, AA&N can be optimized a lot: AA&N, rolled loops, double[][] -> > - * double[][]: 21.162 seconds AA&N, rolled loops, float[][] -> > float[][]: no > - * improvement, but at some stage Hotspot might start doing SIMD, so > let's > + * Also, AA&N can be optimized a lot: > + * AA&N, rolled loops, double[][] -> double[][]: 21.162 seconds > + * AA&N, rolled loops, float[][] -> float[][]: no improvement, > + * but at some stage Hotspot might start doing SIMD, so let's > * use float AA&N, rolled loops, float[] -> float[][]: 19.979 seconds > - * apparently 2D arrays are slow! AA&N, rolled loops, inlined 1D AA&N > - * transform, float[] transformed in-place: 18.5 seconds AA&N, previous > - * version rewritten in C and compiled with "gcc -O3" takes: 8.5 > seconds > + * apparently 2D arrays are slow! > + * AA&N, rolled loops, inlined 1D AA&N > + * transform, float[] transformed in-place: 18.5 seconds > + * AA&N, previous version rewritten in C and compiled with "gcc -O3" > + * takes: 8.5 seconds > * (probably due to heavy use of SIMD) > * > * Other brave attempts: AA&N, best float version converted to 16:16 > fixed > > > > > > -- > E-Mail: garydgreg...@gmail.com | ggreg...@apache.org > Java Persistence with Hibernate, Second Edition > <http://www.manning.com/bauer3/> > JUnit in Action, Second Edition <http://www.manning.com/tahchiev/> > Spring Batch in Action <http://www.manning.com/templier/> > Blog: http://garygregory.wordpress.com > Home: http://garygregory.com/ > Tweet! http://twitter.com/GaryGregory --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
