The Code;

You will edit your theme’s functions.php. Because of this you should backup before. File’s path is /wp-content/themes/your-theme/functions.php

// Get Image Attachments
function sa_get_image($postid=0, $size='thumbnail') { //it can be thumbnail or full
	if ($postid<1)
	$postid = get_the_ID();
	$thumb = get_post_meta($postid, "thumb", TRUE); // Declare the custom field for the image
	if ($thumb != null or $thumb != '') {
		echo $thumb;
	}
	elseif ($images = get_children(array( //If you upload an image function gets first image
		'post_parent' => $postid,
		'post_type' => 'attachment',
		'numberposts' => '1',
		'post_mime_type' => 'image', )))
		foreach($images as $image) {
			$thumbnail=wp_get_attachment_image_src($image->ID, $size);
			?>
	<?php echo $thumbnail[0]; ?>
	<?php }
		else { //If you don't upload or declare as thumb custom field func. gets custom (default) image
		echo get_bloginfo ( 'template_directory' ); //same as wp-content/themes/your-theme/
		echo '/images/image-pending.gif'; // Put this image into your themes images folder and set the path here
	}
}

You can use this function with your several files like index.php, single.php or anything.

<img src="<?php sa_get_image($post->ID, 'thumbnail'); ?>" />

If you set your thumbnail size 100*100 from wordpress you can get a thumbnail image where you want. Also you can use another function with that. You can style your image’s div or you can use timthumb.

Without Timthumb;

// Show Post Thumbnails
function sa_show_thumb_tim() {
?>
<a href="<?php the_permalink() ?>" rel="bookmark"><img class="thumb" width="100" height"100" src="<?php sa_get_image($post->ID, 'full'); ?>" alt="<?php the_title(); ?>" /></a>
<?php
}

You can use this like this directly. Because we coded function with img tag.

<?php sa_show_thumb(); ?>

With Timthumb;

// Show Post Thumbnails With TimThumb
function sa_show_thumb_tim() {
?>
<a href="<?php the_permalink() ?>" rel="bookmark"><img class="thumb" src="<?php bloginfo('template_directory'); ?>/timthumb.php?src=<?php sa_get_image($post->ID, 'full'); ?>&amp;h=100&amp;w=100&amp;zc=1" alt="<?php the_title(); ?>" /></a>
<?php
}

You can use this like this directly. Because we coded function with img tag and we add timthumb function. You can get the latest version of timhtumb here. And you have to put timthumb.php into your theme’s folder.

<?php sa_show_thumb_tim(); ?>

Best Regards

If you want to do this only you have to change .htaccess file. Just copy this code below and change image path. After that if somebody steal your image/photo the code change this photos with your image. Thief shown like a stupid.

Here is the code;

#disable hotlinking of images with forbidden or custom image option
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www\.)?yourdomain.com/.*$ [NC]
#RewriteRule \.(gif|jpg|png)$ %u2013 [F]
#RewriteRule \.(gif|jpg|png)$ http://www.yourdomain.com/stealingisbad.gif [R,L] 

Copy this code into .htaccess file. If you can’t se this file in your FTP program you can add filter like -a and -l. After that you can see this . (dot) and hidden files.

And we begin…

No-Index for all images

<meta name="robots" content="noimageindex">

Add this code to header.php and Google don’t resume to index your images.

Also if you want to stop directory indexing. Open your robots.txt. This file located in your Root area;

Ex: We have  images and siteimages folders. And we have a robots.txt like this.

User-agent: *
Disallow:

We will change this to;

User-agent: *
Disallow: /images/
Disallow: /siteimages/

Thats All! Have a nice day!