***************************************************************************************************
**   												 **
**   If you want to modify this file in order to add another title in the help, please proceed   ** 
**   like this:											 **
**   1. You can add only titles or subtiles.							 **
**   2. This parser is a beta version, so don't play with it it's very "dummy sensitive".	 **
**												 **
**   If you want to add a title:								 **
**   1. Put the /title; tag .									 **
**   2. Hit enter and then put the title name (if you want).					 **
**   3. Add text if you want (this is not necessary).						 **
**   4. Add subtitles if you want (this is also not necessary).				   	 **
**												 **
**   If you want to add subtitles:								 **
**   1. Put the /subtitles; tag.								 **
**   2. Hit enter and then put the subtitle name (if you want).					 **
**   3. Add text (if you want).									 **
**												 **
**   Once you have changed this file proceed like that.						 **
**   1. Be sure to have java 1.2.								 **
**   2. Be sure to have the parser (HelpFileParser).						 **
**   3. Do java Help.HelpFileParser help.txt in the Help directory.				 **
**   4. The parsed file is now saved in help.txt.str.						 **
**   5. Put the file in the helpfiles directory.						 **
**   6. That's all.										 **
**   												 **
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/title;
Short description of the environment

If you want to learn more about these areas just go to the precise description 
section.

/stitle;
Title

Just the title.

/stitle;
Online Help

In the text area you can see help on what you are pointing at with the mouse. 
The help button displays this help window.

/stitle;
Shape Parameters

In this panel you can choose your shape (rectangle, circle, polygon), 
its texture or color. 
The "negative image" checkbox allow you to see the negative image 
of the output of the retina.

/stitle;
Drawing Surface

On this surface you can draw the shape you chose in the shape parameters panel.
To draw the different shape follow the instructions in the help area.
When the application has started, you can move the shapes.

/stitle;
Output of the retina

On this surface you can see the output of the retina algorithm with the above input.

/stitle;
Parameters of the algorithm

Here you can specify all the parameters needed for the algorithm. 
You can see what the different fields correspond to by having a look at the images of the filters. 
In this panel you can start the simulation, stop it and reset all the fields.

/stitle;
Image of the filters

This image represents the internal structure of the algorithm.
 
/title;
How to use the applet in 2 minutes

If you want to see the result of the retina applet without spending time choosing 
the right parameters follow these intructions:

     1. Click once in the drawing surface to specify a corner of the rectangle.

     2. Click a second time in the drawing surface to specify the opposite corner of the rectangle.

     3. Now click on the start button at the bottom of the applet.

     4. You can now see in the output of the retina region the output of the retina.

     5. Move the rectangle you've just created. 
         To do this simply click once on it and then move the mouse (without pressing the mouse button). 
         Now just have a look at the output of the retina. 

/title;
The Different Areas: Precise description and examples

If you aren't familiar with the applet please read " How to use the applet in 2 minutes " and try the first example.

Once you have done all that, you can read the following description of the differents areas.

/stitle;
The Title area

This is the title of the applet. There is nothing special to say about it.

/stitle;
The Online Help area

There are two components in this area: A button and a text area.
If you click on the button, you just display this page.

In the text area you can see helpful messages:

     1. Informations messages: 
         When you pass over a component you can see what you can do with it.

     2. Manipulation messages: 
         When you start drawing a shape, the messages change during the process. 
         For example, if you draw a circle, the first time you can see that you must 
         click once to specify its center and as soon as you click, you can see that 
         you must now click a second time to specify the radius of the circle.

     3. Error messages: 
         When you enter bad fields in the parameters area, you can see a help 
         message about what is wrong. These messages are in red.

If you aren't familiar with the applet, you must look at the help area. Otherwise you won't understand 
why the applet doesn't do what you want.

/stitle;
The Shape Parameters area

In this area you can choose the shape that you are going to draw in the drawing area. 

You can see that there are 4 parameters:

     1. Shape: 
         You can choose to draw a rectangle, a circle or a polygon. 
         If you want to know how to create a shape, please go to the drawing area section.

     2. Negative Image: 
         If you check this checkbox, you can see the negative image of the output of the retina.
         If you don't check it, the whiter the neurons are, the more stimulated they are. 
         If you check it, this is simply the reverse.

     3. Texture: 
         You can specify the texture of your shape. 
         If you click on "None" then you will have no texture, just a shape with only its borders. 
         Otherwise, if you click on one of the other textures then the shape will be filled with it. 
         For example the texture "Left-Right" means that the left side of the shape will be black 
         and the right side white, the center of the shape is filled with a shading of gray. 
         The "Sinus" and "Random" texture are specials textures. Just have a look at them.

     4. Color: 
         When you click on this button a new frame appears: 
         You can now, by clicking on it, specify what kind of gray you want to have. 
         On the left, you can see the current color and on the right you can see the color 
         you have chosen (when you have clicked once).

The texture you apply on the shape is the last one you chose. For example, if you choose the 
"Left-Right" texture and after that you open the "gray color chooser" window then the texture 
you choose is a uniform "128" gray color because the applet takes into account the last thing you do. 

Otherwise, if you open the "gray color chooser" window and you click on the "100" gray uniform 
color and after that you specify the "None" texture, then the texture choosen is "None".

If you are creating shapes in the drawing surface area or if you are simulating, 
the shape parameters area disables itself. It enables itself again when you have finished creating
your shape or when you finish the simulation.

/stitle;
The Drawing Surface area 

This is the area in which you can draw shapes (if you are not simulating) or where you can 
move them (if you are simulating).

For drawing a rectangle:

     1. Choose "rectangle" in the shape parameters area.
     2. Click once in the drawing surface to specify one corner of the rectangle.
     3. Click a second time in the drawing surface to specifiy the opposite corner of 
         the rectangle (don't keep the mouse pressed like in "paintbrush").
     4. Wait while the computer fills the rectangle with the specified texture.

For drawing a polygon:

     1. Choose "polygon" in the shape parameters area.
     2. Click once in the drawing surface to specify the first point of the polygon.
     3. Click several times to build your polygon 
         (don't keep the mouse pressed like in "paintbrush").
     4. Click near the first point to close it. 
     5. Wait while the computer fills the polygon with the specified texture.

For drawing a circle:

     1. Choose "circle" in the shape parameters area.
     2. Click once in the drawing surface to specify its center.
     3. Click a second time in the drawing surface to specify its radius. 
         The radius can't be larger than the drawing area (don't keep the mouse 
         pressed like in "paintbrush")..
     4. Wait while the computer fills the circle with the specified texture.

You can create as many shapes as you want, but remember that the more shapes the slower the applet is.
When you are creating the shapes, you must finish them before starting the simulation. 
If you try to start the simulation without having finished creating your shapes an error message 
will appear in the online help area.

When the simulation is started then you can move the shapes you've just created. 
To do that click on the shape you want to move and then only move the mouse 
(without keeping the button pressed down). The shape will follow the mouse. 

If you have multiple shapes overlopping then when you click, the applet chooses first the circle, 
then the rectangle, and finally the polygon. 
If you have multiple shapes of the same type then when you click, the applet chooses the first 
one that was created. 

When you want to erase the surface, just click with the right mouse button on it.

/stitle;
The Parameters of the Algorithm area

In this area you can specify all the parameters for the algorithm. 
The differents fields correspond to the image on the right of the area. 
You can see that there are two layer, the cone layer and the horizontal layer. 
If you want to change one of the fields just click on it and put in a value for it 
(the different values allowed are float, integer, long and double). 

You can't change the fields when you are simulating.

If you specified some bad parameters (value equal to or below zero), 
an error message will appear in the online help area. 

If you want to see a correct output, you must specify the parameters in the range that is 
given in the online help area. If you don't then you will probably see some strange 
output because of numerical instability.

The last textfield ("Waiting time between each epoch") is here to slow the applet. 
If you have a very fast machine and you can't see the output of the retina because 
it's too fast then you can specify in this textfield the time (in milliseconds) the algorithm 
will sleep between each loop. 
You can also use this parameter to better see what the algorithme does.

At the bottom of the applet you can see three buttons: "Start", "Stop" and "Reset Fields". 
The "Start" button starts the algorithm with the specified parameters. 
When you have clicked on it, you can move the shapes you've just created in the drawing surface area. 
You can only do that, all the fields in the applet are disabled, except the "Stop" button. 

When you click on this last button, then the simulation stops and you can draw shapes 
and enter others parameter. 

If you hit on the "Reset Fields" button then the fields of the algorithm are set with such values 
that you can see a good result on the output of the retina.

/stitle;
The Output of the Retina area

In this area you can see the output of the retina algorithm. 
If you checked "Negative Image" in the shape parameters area then the darker the pixels are,
 the more the neurons are stimulated. If you didn't check it then it is the reverse.

If you see some strange results, this is probably due to numerical instability. 
Just put in the parameters area fields that suit well (or click on the "Reset fields" button).

/stitle;
The image of the filters area

In this area you can see what the algorithm of the retina is based on. 
The output pixel is calculated with two RC filters and with the influence of its neigbourhood. 
The value of each pixels depends on the value of the others.
 
/title;
Troubleshooting

There are some explanation about troubles that you may have when you start the applet.
If you have found a bug, please mail-me:
	Sebastien.Baehni@epfl.ch

/stitle;
I use "Netscape" and I have no images nor the help button

Well for the images, this is due to a bug of "netscape" with its media tracker. 
For the help this is because of the hard security of "netscape".
Sorry but you just can't see the images and the help.

If you want also to view all the applet with the help, try the solutions.

Solutions:
     1. If you can have "Internet Explorer" then try to use the applet with it (I'm sure that it will work).
     2. Download the applet. 
         If you have WindowsXX:
	Unzip it with gunzip.
         If yout have Linux or Unix:
	Unzip it with gunzip and untar it (tar -xvf retina.tar).         
     3. If you have the java development kit you can just type in a console "java RetineSimulation" or
         "appletviewer RetineSimulation.html" in the directory where you've just unzipped the applet.

/stitle;
I use "Netscape" and when I use the applet, it is very very slow

This is due to netscape or to your slow machine.

Solutions:
     1. If you can have "Internet Explorer" then try to use the applet with it (I'm sure that it will work).
     2. Download the applet. 
         If you have WindowsXX:
	Unzip it with gunzip.
         If yout have Linux or Unix:
	Unzip it with gunzip and untar it (tar -xvf retina.tar).         
     3. If you have the java development kit you can just type in a console "java RetineSimulation" or
         "appletviewer RetineSimulation.html" in the directory where you've just unzipped the applet.

/stitle;
An error message occurs when I use the applet

Well, the applet has been tested with no bugs.

Please mail me and be the more precise you can:
	Sebastien.Baehni@epfl.ch