field_info_field API to get human readable name
You can't, no - the labels are set statically in code (in image.field.inc), they don't come from the API:

// Add the additional alt and title fields.
$element['alt'] = array(
  '#title' =&gt; t('Alternate text'),
  '#type' =&gt; 'textfield',
  '#default_value' =&gt; isset($item['alt']) ? $item['alt'] : '',
  '#description' =&gt; t('This text will be used by screen readers, search engines, or when the image cannot be loaded.'),
  // @see http://www.gawds.org/show.php?contentid=28
  '#maxlength' =&gt; 512,
  '#weight' =&gt; -2,
  '#access' =&gt; (bool) $item['fid'] &amp;&amp; $settings['alt_field'],
);
$element['title'] = array(
  '#type' =&gt; 'textfield',
  '#title' =&gt; t('Title'),
  '#default_value' =&gt; isset($item['title']) ? $item['title'] : '',
  '#description' =&gt; t('The title is used as a tool tip when the user hovers the mouse over the image.'),
  '#maxlength' =&gt; 1024,
  '#weight' =&gt; -1,
  '#access' =&gt; (bool) $item['fid'] &amp;&amp; $settings['title_field'],
);