[opensource-dev] Openjpeg/KDU the cold hard metrics

Sheet Spotter sheet.spotter at gmail.com
Sun Sep 26 00:02:39 PDT 2010

I created a crude profiling tool to determine where to focus on improving
the performance of OpenJPEG v2.

The profiling tool records the number of function calls and combined
execution time for every function in the main source files (openjpeg.c,
j2k.c, dwt.c, tcd.c, t1.c, mqc.c, and raw.c).

Results from running the test harness on the 748 files from the
"local_assets" folder were recorded in a CSV (Comma-Separated Value) format.
The results were placed here:

The three columns in the file are:
1. Function name
2. Number of times the function was called
3. Combined execution time for the function. 
The order the rows appear in the file is not significant. (You can sort the
rows in any order you like after importing the file into a spreadsheet.)

Enabling the profiling tool definitely distorts the results. Overall
execution time for the test increased from 21 seconds to 129 seconds. 

The crude profiling tool was able to identify where most of the decoding
time is spent. Only a small number of routines are responsible for most of
the execution time. Hopefully this information can lead to improvements in
the performance of the OpenJPEG v2 library.

Sheet Spotter

-----Original Message-----
From: Robin Cornelius [mailto:robin.cornelius at gmail.com] 
Sent: September 23, 2010 5:37 AM
To: Sheet Spotter
Cc: opensource-dev
Subject: Re: [opensource-dev] Openjpeg/KDU the cold hard metrics

On Thu, Sep 23, 2010 at 3:40 AM, Sheet Spotter <sheet.spotter at gmail.com>
> There may be another option for obtaining a common set of J2C files for
> comparison.
> Viewer 2 installs 784 JPEG-2000 files (*.j2c) in the "local_assets" folder
> under the main install folder (e.g., "C:\Program
> The "j2k_metric" test harness decoded all 784 files from the
> folder without errors. The OpenJPEG 1.3.0 library was 3.7 times slower
> the KDU library that comes with Viewer (the current release
> version).

Hi (again) Sheet and everyone else,

I've started another sheet with a fresh set of results on another
system of mine, please feel free to add your own tests rows


If you want to compare to KDU you need to compare to KDU on your
system don't compare to by KDU results or anyone elses, thats not a
fair comparision.

OJP 2.0 is not playing nice with the local_asset texture set needs some


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