Fetch images only from wordpress posts - image

Question

In wordpress, when a post category (or tag) is clicked, all posts that match the clicked category (or tag) is returned, because of <?php the_content(); ?>
In my case, every post has an image in it, so how can I only fetch the images when a category (or tag) is clicked? I'm not familiar what code I need to use.
Update: I'm trying not to use plugins. My apologies for not mentioning that earlier. What I'm trying to achieve is something like The Sartorialist - All posts have images, click on any category (or tag) associated with any post and only images are fetched.
Update 2: I tried this:
<?php
$args = array(
'post_type' => 'attachment',
'numberposts' => -1,
'post_status' => null,
'post_parent' => $post->ID
);
$attachments = get_posts( $args );
if ( $attachments ) {
foreach ( $attachments as $attachment ) {
echo '<li>';
echo wp_get_attachment_image( $attachment->ID, 'full' );
echo '</li>';
}
}
?>
The only weird thing is, and I'm trying to figure out, another image from the media library also shows up, without it being in any of my posts.
I also found this plugin which is very close to what I want, but unfortunately it has to be in a separate page, not the in category page.

Answer 1

You can achieve this with something like this:
<?php
function getImage($num) {
global $more;
$more = 1;
$link = get_permalink();
$content = get_the_content();
$count = substr_count($content, '<img');
$start = 0;
for($i=1;$i<=$count;$i++) {
$imgBeg = strpos($content, '<img', $start);
$post = substr($content, $imgBeg);
$imgEnd = strpos($post, '>');
$postOutput = substr($post, 0, $imgEnd+1);
$postOutput = preg_replace('/width="([0-9]*)" height="([0-9]*)"/', '',$postOutput);;
$image[$i] = $postOutput;
$start=$imgEnd+1;
}
if(stristr($image[$num],'<img')) { echo ''.$image[$num].""; }
$more = 0;
}
?>
source