## Thursday, June 26, 2008

### How to open .djvu files under linux

Under linux, you can open djvu file by web browser . Bust you need install plug in.

Second you need do :

./configure - -prefix=$path where you want to install$

make

make install

Third open Konqueror, select "Settings->Configure Konqueror" and check "Plugins". If you can't see $prefix path$/lib/netscape/plugins, you need type new and add this file in.
Then you can type scan for new plugins. After that ,you type "Plugins", you will see the file $/lib/netscape/plugins/nsdejavu.so there.. If you want to use Opera, you can do: cd /home/username/.opera vi pluginpath.ini After open "pluginpath.ini", you can add "$\$/lib/netscape/plugins/nsdejavu.so=1" to that file.
Work very nicely.

Ok, congratulation, you can see djvu by konqueror now....

http://linux.derkeiler.com/Mailing-Lists/Fedora/2007-01/msg00091.html
(This is very useful)

http://djvu.sourceforge.net/
(This website is very bad I think..Because you can't find how to install the plugins to web browsers)

### "How is it that little children are so intelligent and men so stupid? It must be education that does it." Alexandre Dumas

"How is it that little children are so intelligent and men so stupid? It must be education that does it."

## Saturday, June 21, 2008

### The lower level vision is more difficult than higher vision

I think so especially when you work on industry product developing .

## Friday, June 20, 2008

I spent too much time on the parallel curve.

It seems very simple.

so when I can't finish it perfectively , I feel so sad...

Today, I check many papers to find that no one can do it perfectly for any situation and any image.

Many professors and Doctors do it many years to improve their work...

I feel happy about that there are so many people stand with me...^_^.I am not alone.

In scientific field , there are no problem can be solved perfectly.

We just can get a better answer under special situation and presumption..

What I need learn is to grasp the most important thing and find the nearer way to get the goal.

Although it's not perfect, but it can be better and better.

## Tuesday, June 17, 2008

### parallel curve (The parallel curve of parabola is not parabola)

It's very interesting that the parallel curve of parabola is not parabola..you can draw a parabola on your paper and use pen to go on by the line; you will see the parallel of the parabola will cross itself, so that's true the parallel of the parabola is not parabola; It's same to circle and sin curve;

Here is a useful formula to calculate the parallel curve and curvature and the radius of the curvature:

$X[x,y]=x+\frac{ay'}{\sqrt {x'^2+y'^2}}$

$Y[x,y]=y-\frac{ax'}{\sqrt {x'^2+y'^2}}$

Here y=f(t);x=g(t); X and Y are coordinate of the parallel curve.

See more:
http://en.wikipedia.org/wiki/Parallel_curve
http://www.jstor.org/stable/3027202?seq=5

## Monday, June 16, 2008

### If you range the data by the loop in C++

Rember that it 's a wrong way to do this like:

Increase range:

for(int i=0;i<100;i++)
{ int x=a[i] ;
for(int j=i+1;j<100;j++)
{ int y=a[j];
if(y<x)
{ int t=a[j];a[j]=a[i];a[i]=t;}
}
}

Why that's wrong??
The reason is a[i] in the loop has been changed, but the x isn't changed. so It's wrong !

you can do it correctly like:

for(int i=0;i<100;i++)
{
for(int j=i+1;j<100;j++)
{ int x=a[i] ;
int y=a[j];
if(y<x)
{ int t=a[j];a[j]=a[i];a[i]=t;}
}
}

or

for(int i=0;i<100;i++)
{ int x=a[i] ;
for(int j=i+1;j<100;j++)
{
int y=a[j];
if(y<x)
{ x=y; int t=a[j];a[j]=a[i];a[i]=t;}
}
}

### Conference ISVC(4th Int Sym Visual Computing). DeadLIne: JUly 21

July 21, 2008 Paper submissions due
September 1, 2008 Notification of acceptance
September 15, 2008 Final camera ready papers due
December 1-3, 2008 Symposium

## Friday, June 13, 2008

### How to match pair of braces in gvim??

you can use % to find a pair of {} or () // etc.....

see more :http://www.moolenaar.net/habits.html
O-Town : All or Nothing
Spice Girls : 2 Become 1

2 Become 1 Lyrics

Spice Girls Lyrics
2 Become 1 Lyrics

## Tuesday, June 10, 2008

### Programmer

you always need change............... improve............

## Friday, June 6, 2008

### Tired time

Tired time for me is 3:30 Pm everyday....

Now I only want to sleep.....

But works on the table are waiting for me ..

So...
just still living and working..

## Thursday, June 5, 2008

### Image coordinate and World coordinate

If you want to show a world coordinate image by OpenCv or Matlab, you need to know the difference between Image coordinate system and the world coordinate system.

The main difference is the original point, which is uper-left in image coordinate and bottom-middle in IPM (Inverse projection mapping)world coordinate.

## Wednesday, June 4, 2008

### Copy and cat the string (Char*) in C++

char* newname=new char[100];
char* new="new";
char* name="name";
//first you need strcpy to copy content to newname. You can't use strcat instead of strcpy first.
strcpy(newname,new);//newname="new"
//Now you can use strcat to cat the string. But be careful about the string length.. Max length is 100-1..
strcat(newname,name);//newname="newname"

if(newname)
{delete[] newname;}