[vtkusers] compare speed of dilate and erode in itk, vtk and matlab
Chen Fu
novalet at yahoo.com.cn
Thu May 1 07:39:31 EDT 2003
Hi Lius,
Yes, i build ITK and my demo in both "Release" option
and "Debug" option in vc6, but not directly select in
CMake.
To my understand, they are the same. BTW, vc6 report a
internal error(should call MS support according to the
error info) when compile release option on
itkDanielssonDistanceMapImageFilter.txx Line 286, i
have to seperate it into two lines to get pass, but in
debug option it is not a problem.
OutputImageType::PixelType p = static_cast<typename
OutputImageType::PixelType>(sqrt( distance ));
dt.Set( p );
I don't know the reason, any idea?
You are right. The "release" is much quicker than
"debug" option. But compare to matlab, it is still
slower.
My code list below, it takes itk release option 56
seconds to finish, debug option takes 608 seconds,
while vtk(written in tcl script) cost 20 seconds,
matlab code cost only 1.6 seconds.
I carefully exam the code and at last find out the
speed of matlab is benefit from computing on really
blackwhite image format which means 8 pixels in one
byte. If i replace "BW = im2bw(Ic, graythresh(Ic));"
with "BW = Ic", matlab will compute in a gray image
mode, that will take 19 seconds to finished.
>From these tests, i think the morphology operators in
itk deserve more efforts to enhance their performance.
Maybe the pure iterator system is expensive for visit
every pixel. But i am not familiar enough with source
code yet, so can not give any really constructive
suggestion, sorry. These tests are just my exercises
to use itk and vtk.
matlab code:
========================================
t0 = clock;
I = imread('d:\nova\pearbig.tif');
Ic = imcomplement(I);
BW = im2bw(Ic, graythresh(Ic));
se = strel('disk', 6);
BWc = imclose(BW, se);
BWco = imopen(BWc, se);
mask = BW & BWco;
etime(clock, t0)
=======================================
my itk code:
=======================================
// itkTester2.cpp : Defines the entry point for the
console application.
//
#include "stdafx.h"
#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkBinaryThresholdImageFilter.h"
#include <itkBinaryDilateImageFilter.h>
#include <itkBinaryErodeImageFilter.h>
#include <itkBinaryBallStructuringElement.h>
#include <time.h>
void itkBinaryThresholdImageFilterTest()
{
// Use a random image source as input
typedef unsigned char PixelType;
typedef itk::Image< PixelType, 2 > ImageType;
typedef itk::ImageFileReader< ImageType >
ReaderType;
ReaderType::Pointer source = ReaderType::New();
source->SetFileName("d:\\pearbig.png");
// Declare the type for the binary threshold
binaryThreshold
typedef itk::BinaryThresholdImageFilter< ImageType,
ImageType > FilterType;
// Create a binaryThreshold
FilterType::Pointer binaryThreshold =
FilterType::New();
// Setup ivars
PixelType lower = 180;
PixelType upper = 255;
binaryThreshold->SetUpperThreshold( upper );
binaryThreshold->SetLowerThreshold( lower );
PixelType inside = 0;
PixelType outside = 255;
binaryThreshold->SetInsideValue( inside );
binaryThreshold->SetOutsideValue( outside );
// Connect the input images
binaryThreshold->SetInput( source->GetOutput() );
// Declare the type for the structuring element
typedef itk::BinaryBallStructuringElement<unsigned
char, 2>
KernelType;
// Create the structuring element
KernelType ball;
KernelType::SizeType ballSize;
ballSize[0] = 5;
ballSize[1] = 5;
ball.SetRadius(ballSize);
ball.CreateStructuringElement();
// Declare the type for the morphology Filter
typedef itk::BinaryDilateImageFilter<ImageType,
ImageType, KernelType>
BinaryDilateType;
typedef itk::BinaryErodeImageFilter<ImageType,
ImageType, KernelType>
BinaryErodeType;
//Close = Erode then Dilate
BinaryErodeType::Pointer binaryErode =
BinaryErodeType::New();
binaryErode->SetInput(binaryThreshold->GetOutput() );
binaryErode->SetKernel( ball );
binaryErode->SetErodeValue( 255 );
BinaryDilateType::Pointer binaryDilate =
BinaryDilateType::New();
binaryDilate->SetInput(binaryErode->GetOutput() );
binaryDilate->SetKernel( ball );
binaryDilate->SetDilateValue( 255 );
//Open = Dilate then Erode
BinaryDilateType::Pointer binaryDilate2 =
BinaryDilateType::New();
binaryDilate2->SetInput(binaryDilate->GetOutput() );
binaryDilate2->SetKernel( ball );
binaryDilate2->SetDilateValue( 255 );
BinaryErodeType::Pointer binaryErode2 =
BinaryErodeType::New();
binaryErode2->SetInput(binaryDilate2->GetOutput() );
binaryErode2->SetKernel( ball );
binaryErode2->SetErodeValue( 255 );
typedef itk::ImageFileWriter< ImageType >
WriterType;
WriterType::Pointer writer = WriterType::New();
writer->SetFileName("d:\\pearlite2.png");
writer->SetInput (binaryErode2->GetOutput() );
writer->Update();
}
void main(int argc, char* argv[])
{
clock_t a = clock();
itkBinaryThresholdImageFilterTest();
clock_t b = clock();
printf("time %lf\n", 1.0*(b-a)/CLOCKS_PER_SEC);
}
======================================
vtk tcl script
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
package require vtk
vtkPNGReader reader1
reader1 SetFileName d:/pearbig.png
vtkImageCast cast
cast SetOutputScalarTypeToFloat
cast SetInput [reader1 GetOutput]
vtkImageThreshold thresh
thresh SetInput [cast GetOutput]
thresh ThresholdByUpper 180
thresh SetInValue 0.0000
thresh SetOutValue 255.0000
thresh ReleaseDataFlagOff
vtkImageOpenClose3D my_close
my_close SetInput [thresh GetOutput]
my_close SetOpenValue 0.0000
my_close SetCloseValue 255.0000
my_close SetKernelSize 11 11 1
my_close ReleaseDataFlagOff
vtkImageOpenClose3D my_open
my_open SetInput [my_close GetOutput]
my_open SetOpenValue 255.0000
my_open SetCloseValue 0.0000
my_open SetKernelSize 11 11 1
my_open ReleaseDataFlagOff
vtkImageToImageStencil imageToStencil
imageToStencil SetInput [my_open GetOutput]
imageToStencil ThresholdBetween 0 127
# silly stuff to increase coverage
#imageToStencil SetUpperThreshold [imageToStencil
GetUpperThreshold]
#imageToStencil SetLowerThreshold [imageToStencil
GetLowerThreshold]
vtkImageStencil stencil
stencil SetInput [reader1 GetOutput]
stencil SetBackgroundValue 120
stencil ReverseStencilOn
stencil SetStencil [imageToStencil GetOutput]
vtkPNGWriter writer
writer SetInput [ stencil GetOutput ]
writer SetFileName d:/pearbig2.png
writer Write
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--- Luis Ibanez <luis.ibanez at kitware.com> 的正文：>
> Hi Chen,
>
> The ITK implementation of morphology operations
> also decompose the processing of the boundary
> regions. This is done by the SmartNeighborhood
> iterator.
>
> So, the difference in preformance is not due to
> boundary processing.
>
>
>
> About your speed comparison:
>
> 1) In what platform are you compiling ITK ?
>
> 2) Did you enable the "Release" option in
> CMake when configuring ITK ?
>
> Enabling "Release" will add the flags for
> code optimization, given that most of ITK
> is templated code, there is a dramatic speed
> difference between code compiled for debug
> and code compiled for release.
>
>
>
> Regards,
>
>
> Luis
>
>
> -----------------------
>
> Chen Fu wrote:
> > Hi!
> > I recently compare the morphology operation in
> vtk,
> > itk and matlab. To my surprise, vtk and itk is
> much
> > slower than matlab.
> > I believe the problem is the boundary processing.
> In
> > vtk and itk code, every pixel must take 8 compares
> to
> > confirm whether it is inside the image boundary.
> But
> > in matlab, the boundary is preprocessed by
> extending
> > the size of image, so get rid of such compares. I
> will
> > try to do some modify of itk code to enhance its
> > performance, but i am not very clearly how to do
> > extend the image in itk's pipeline architecture.
> > Maybe somebody can give me some hints?
> >
> >
> > =====
> > Remote Scensing Satellite Ground Station
> > Chinese Academy of Science
> >
>
=====
Remote Scensing Satellite Ground Station
Chinese Academy of Science
_________________________________________________________
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