WordPress black and white thumbnail

First we need to create a new thumbnail using add_image_size(). We’ll use the same thumbnail settings from the WordPress Media page in the wp-admin. Add this to your functions.php file within the PHP tags:

add_action(‘after_setup_theme’,’bw_images_size’);function bw_images_size() {    $crop = get_option(‘thumbnail_crop’)==1 ? true : false;    add_image_size(‘thumbnail-bw’, get_option(‘thumbnail_size_w’), get_option(‘thumbnail_size_h’), $crop);}

With that in place, we can now add the following function which will automatically create a black and white thumbnail:

add_filter(‘wp_generate_attachment_metadata’,’bw_images_filter’);

function bw_images_filter($meta) {

    $file = wp_upload_dir();

    $file = trailingslashit($file[‘path’]).$meta[‘sizes’][‘thumbnail-bw’][‘file’];

    list($orig_w, $orig_h, $orig_type) = @getimagesize($file);

    $image = wp_load_image($file);

    imagefilter($image, IMG_FILTER_GRAYSCALE);

    //imagefilter($image, IMG_FILTER_GAUSSIAN_BLUR);

    switch ($orig_type) {

        case IMAGETYPE_GIF:

            $file = str_replace(“.gif”, “-bw.gif”, $file);

            imagegif( $image, $file );

            break;

        case IMAGETYPE_PNG:

            $file = str_replace(“.png”, “-bw.png”, $file);

            imagepng( $image, $file );

            break;

        case IMAGETYPE_JPEG:

            $file = str_replace(“.jpg”, “-bw.jpg”, $file);

            imagejpeg( $image, $file );

            break;

    }

    return $meta;

}

Whenever you upload an image, this function will create a new black and white thumbnail automatically. I also added a Gaussian Blur but commented it out. Remove those two slashes “//” to add a Gaussian Blur to your new black and white thumbnail. See otheravailable filters.

get_post_thumbnail();1 within your WordPress loop to display the two images for the effect:

Once you’ve added the above code, you can use.

get_post_thumbnail();1 within your WordPress loop to display the two images for the effect:

1if(function_exists(‘has_post_thumbnail’) && has_post_thumbnail()) {

    echo ‘<a href=”’.get_permalink().’” class=”fade-image”>’;

    the_post_thumbnail(‘thumbnail-bw’, array(‘class’=>’fade-image-a’));

    the_post_thumbnail(‘thumbnail’, array(‘class’=>’fade-image-b’));

    echo ‘</a>’;

}

WordPress custom fields – Post

We can display meta values like this

<p>Meta information for this post:</p>
<?php the_meta(); ?>

Output is 

<ul class='post-meta'>
<li><span class='post-meta-key'>your_key:</span> your_value</li>
</ul>

WordPress changing order of posts.

Paste this just before calling Loop

global $query_string;

query_posts($query_string.’&order=ASC’); 

The above code is to display older posts first (Just reverse of wordpress default posts display).

PHP Simple CAPTCHA CODE using SESSION

Create this file :

eg : captcha.php

<?php
session_start();
$ranStr = md5(microtime());
$ranStr = substr($ranStr, 0, 6);
$_SESSION[‘cap_code’] = $ranStr;
$newImage = imagecreatefromjpeg(“cap_bg.jpg”);
$txtColor = imagecolorallocate($newImage, 0, 0, 0);
imagestring($newImage, 5, 5, 5, $ranStr, $txtColor);
header(“Content-type: image/jpeg”);
imagejpeg($newImage);
?>

FORM like this

<form action=”” method=”post”>
<label>Name:</label><br/>
<input type=”text” name=”name” id=”name”/>
<label>Message:</label><br/>
<textarea name=”msg” id=”msg“></textarea>
<label>Enter the contents of image</label>
<input type=”text” name=”captcha” id=”captcha” />
<img src=’captcha.php’ />
<input type=”submit” value=”Submit” id=”submit”/>
</form>

ACTION PAGE : 

<?php
if ($_SERVER[‘REQUEST_METHOD’] == ‘POST’)
{
if ($_POST[‘captcha’] == $_SESSION[‘cap_code’]) 
{
// Captcha verification is Correct. Do something here!
}
else 
{
// Captcha verification is wrong. Take other action
}
}
?>

Thank you.