[Insight-users] Performance regression ImageSeriesReader? (with test)

[Bradley Lowekamp]

On Mar 22, 2010, at 1:17 PM, Roger Bramon Feixas wrote:
> 
> Bradley,
> 
> I did the test using a computer which has Itel Core 2 Quad 2.4 GHz CPU with 4GB RAM. The OS is Windows XP 32bits. The data is on locale. During the execution one of the CPU's is 100% full. 
> 
> I did the test using 3 CT models:
> 
> Head CT (http://mri.radiology.uiowa.edu/VHDicom/VHFCT1mm/VHF-Head.tar.gz)		
> 	
>                 Reading directory   UpdateOutputInformation     UpdateLargestPossibleRegion
> Itk 2.8                       390                         4                            1409
> Itk 3.16                      394                       452                            1502

123MB
234 files
6% gain in UpdateData
an additional 30% from UpdateOutputInformation

> ________________________________________
> 
> CT example study which we work with (http://dl.dropbox.com/u/3613789/ct_anonymized.zip)
> 
>                 Reading directory   UpdateOutputInformation     UpdateLargestPossibleRegion
> Itk 2.8                      1024                         9                            2260
> Itk 3.16                     1030                      1666                            2975

130MB
243 files
30% gain in UpdateData
an additional 56% from UpdateOutputInformation

> 
> _________________________________________
> 
> CALIX/CT1 abdomen/D30MN BILISCOPIN from OSIRIX Data (http://pubimage.hcuge.ch:8080/DATA/CALIX.zip)
> 
>                 Reading directory   UpdateOutputInformation     UpdateLargestPossibleRegion
> Itk 2.8                       660                         7                           20380
> Itk 3.16                      652                       850                           21053

25MB
238 files
3% gain in UpdateData
an additional 4% from UpdateOutputInformation

Clearly the additional read of the metadata in UpdateOutputInformation is part cause of of the slow down. 

However there are a lot of odd performance numbers here. Why is OSIRIX data so slow? Why is the CT example's directory reading and UpdateData so slow? I don't know enough about the DICOM format to know if there are different forms of compression affecting things here or what. If the header is compressed, then the update of the meta data is clearly going to be a more computation intensive. Or perhaps it's the size or number of entries of the meta data ( which I didn't check ) causing the performance difference.


========================================================
Bradley Lowekamp  
Lockheed Martin Contractor for
Office of High Performance Computing and Communications
National Library of Medicine 
blowekamp at mail.nih.gov


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