Create Customize Filed in Joomla

This code is used to create a customize field which is used to upload a image and display it while creating a new article or product in your component.
It will display image when you edit any item from your component and you can upload other image.
create a file in administrator/components/com_your_component/models/filed/uploadimage.php

/**
 * @package     Joomla.Platform
 * @subpackage  Form
 *
 * @copyright   Copyright (C) 2005 - 2014 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE
 */
defined('JPATH_PLATFORM') or die;
jimport('joomla.image.image');

/**
 * Form Field class for the Joomla Framework.
 *
 * @since  0.0.6
 */
class JFormFieldUploadImage extends JFormField
{
    /**
     * The form field type.
     *
     * @var      string
     * @since   1.6
     */
    protected $type = 'UploadImage';
    /**
     * Method to get the field input markup.
     *
     * @return   string   The field input markup.
     *
     * @since   1.6
     */
    protected function getInput()
    {
        $html = array();
        $html[] = '<div class="button2-left">';
        $html[] = '<input type="file" name="' . $this->name . '"/>';
        $html[] = '</div>';
        $html[] = '<div>';
        $html[] = '<img  src="' . JUri::root() . 'media/com_your_component/images/category/                   ' . $this->value . '"/>';
        $html[] = '<input type="hidden" value="' . $this->value . '" name="jform[hiddenimag                     e]"/>';
        $html[] = '</div>';

       return implode("\n", $html);
    }
}

create a file in administrator/components/com_your_component/models/forms/uploadimage.xml

<?xml version="1.0" encoding="utf-8"?>
<form>
    <fieldset>
        <field name="image" 
               default=""
               type="UploadImage"
               hide_none="1 "
               label="COM_YOUR_COMPONENT_FIELD_PARAMS_IMAGE_LABEL"
               description="COM_YOUR_COMPONENT_FIELD_PARAMS_IMAGE_DESC"
               componentname="com_your_component"
         />
    </fieldset>
</form>

add enctype="multipart/form-data" attribute of the from in below file:

administrator/components/com_your_component/views/your_view/tmpl/edit.php
In administrator/component/com_your_component/models/your_model.php
write below code into save function

$table = $this->getTable();
$input = JFactory::getApplication()->input;
$pk = (!empty($data['id'])) ? $data['id'] : (int) $this->getState($this->getName() . '.id');
$isNew = true;
$hiddenImage = array();
$hiddenImage = $input->post->get('jform', array(), array());
// Retrieve file details from uploaded file, sent from upload form
$file = $input->files->get('jform');

// Clean up filename to get rid of strange characters like spaces etc
$data['image'] = time() . '_' . JFile::makeSafe($file['image']['name']);

// Set up the source and destination of the file
$src = $file['image']['tmp_name'];
$dest = JPATH_SITE . '/media/com_your_component/images/category/' . $data['image'];

// First check if the file has the right extension, we need jpg only
if (!empty($file['image']['name']))
{
    if (preg_match('/(.)+jpe*g|gif|png/i', $file['image']['name']))
    { 
        if (!JFile::upload($src, $dest) )
        {
            $this->setError(JText::_('Invalid Image Type'));
            return false;
        }
        else
        {
            unlink(JPATH_SITE . '/media/com_your_component/images/category/' . $hiddenImage['hiddenimage']);
         }
    }
}
elseif (!empty($hiddenImage['hiddenimage']))
{
    $data['image'] = JFile::makeSafe($hiddenImage['hiddenimage']);
}
else
{
    $this->setError(Jtext::_('Invalid Image Type Not upload condition..'));
    
    return false;
}