如何使用composer将laravel的新包添加到不同文件夹中的多个项目中？

i haven't got this able to work. I have been googled this for days so hopefully someone can help me or shed light for this.

I have installed Laravel by using composer and practiced programming a simple application. Then i wanted to carry on programming another application and i copied all the folders of my previous (very first) laravel project into another folder inside the htdocs folders. I am using XAMPP on windows.

Then i did the same and have four projects in different folders. I changed the original folder name of my very first laravel app in order to keep track of what i have been programming.

So now i am stuck in image uploading in another project. I downloaded the Intervention/image package by using Composer, it did well, I typed composer require intervention image and it was installed successfully.

Then i ran into this error:

Symfony \ Component \ Debug \ Exception \ FatalErrorException (E_ERROR) Class 'Image' not found

Then i thought that possibly composer installed it into my original laravel project. I have tested all my applications by calling this image class and i still get this error. Now i am lost, i don't know where the intervention/image package was installed :( I don't find a folder that is named intervention or something like that.

Tell me how i can find out where is composer pointing to or installing the new packages?

I have also tried configuring the intervention/image in all the projects i have according to this website: http://image.intervention.io/getting_started/installation And it says to add the following two lines in app/config/app.php

"In the $providers array add the service providers for this package.

'Intervention\Image\ImageServiceProvider'

Add the facade of this package to the $aliases array.

'Image' => 'Intervention\Image\Facades\Image' "

And i Have done that in all the applications and i get still another error:

Symfony \ Component \ Debug \ Exception \ FatalErrorException (E_ERROR) 
Class 'Intervention\Image\ImageServiceProvider' not found

My code in the controller files looks like this so far:

//UPLOAD PICTURE
public function getUploadPicture(){
    return View::make('account.uploadpicture');
}

//POST función que sube la foto del usuario
public function postUploadPicture(){
    var_dump($image=Input::file('photo'));
    $image=Input::file('photo');
    var_dump($image->getRealPath());
    Image::make($image->getRealPath());
    die();
    return Redirect::route('account-upload-picture')
                    ->with('global','<div class="alert alert-success" role="alert">
                            <button type="button" class="close" data-dismiss="alert"><span aria-hidden="true">&times;</span><span class="sr-only">Cerrar</span></button>
                            ¡La foto se ha enviado exitosamente!</div>')
                    ->withInput();
}

So now i have three questions,

1. how do i get to know what the default directory is of composer?
2. How do i know where the Intervention/Image was installed?
3. how do i add another project so that it may be able to use the Intervention/image too as well as future projects?

You'll need to add the package to your composer file. In laravel's project root, open up the composer.json file and add "intervention/image": "2.*", to the require section of the json. Then run composer update to fetch the package.