imagefilter.module

<?php
/**
 * Implementation of hook_filter_info().
 */
function imagefilter_filter_info() {
  return array('imagefilter' => array(
    'title' => t('Insert Image'),
    'description' => t('Inserts images nicely.'),
    'process callback' => '_imagefilter_process',
    'tips callback' => '_imagefilter_filter_tips',
  ));
}

/**
 * Filter tips callback for imagefilter filter.
 */
function _imagefilter_filter_tips($filter, $format, $long) {
  if ($long) {
    $output = t('You can use the following syntax ![Description](1.jpg).');
  } else {
    $output = t('![Description](1.jpg)');
  }

  return $output;
}

/**
 * Implementation of hook_init().
 */
function imagefilter_init() {
  drupal_add_css(drupal_get_path('module', 'imagefilter') . '/imagefilter.css');
}

/**
 * Processing function to apply the imagefilter filters
 *
 * @param string $text
 *    The text to apply the filter on.
 * @param integer $format
 *    ID if the input format whose settings to use when applying the filters.
 * @return string
 *    The filtered text.
 */
function _imagefilter_process($text, $filter, $format, $langcode, $cache, $cache_id) {
 $image_with_float = '/\!\[(.*)\]\((.*)\)\s*({(.*)})*/';
 $replacement_with_float= '<a href="?q=sites/default/files/styles/large/public/images/\2" class="colorbox" title="\1" rel="list"><img src="?q=sites/default/files/styles/medium/public/images/\2" class="\4"/></a>';
 $image = '/\!\[(.*)\]\((.*)\)/';
 $replacement = '<a href="?q=sites/default/files/styles/large/public/images/\2" class="colorbox" title="\1" rel="list"><img src="?q=sites/default/files/styles/medium/public/images/\2"/></a>';
 $text = preg_replace($image_with_float, $replacement_with_float, $text);
 return preg_replace($image, $replacement, $text);
}

function imagefilter_help($path, $arg) {
  if ($path == 'admin/help#imagefilter')
    return t('<p>For more information look at <a href="https://github.com/fmms/drupal-imagefilter">https://github.com/fmms/drupal-imagefilter</a>.</p>');
}