WordPress function to detect if is a photo is panoramic.

is_pano.php

<?php
/**
 * Given an attachment_id and a definition of panoramia, detect if a photo is panoramic
 *
 * @param int 		$attachment_id	the attachment_id for the image
 * @param mixed 	$min_ratio	the aspect ratio that defines panoramia
 * @return boolean	returns true if image is panoramic, otherwise returns false
 */
function sjf_deh_is_pano( $attachment_id, $min_ratio='2' ){
	
	//the ID for this post, of the attachment post type, make sure it's an integer
	if( !is_int( $attachment_id ) ) { return false; }
	
	/**
	 * the minimum ratio of width to height in order to consider an image panoramic
	 * make sure it's numeric (it could be an int or a float)
	 */
	if( !is_numeric( $min_ratio ) ) { return false; }
	
	/**
	 * an array that contains information about the image
	 * it's important to get the full size so as not to get a wp resized version
	 */
	$att_src_array = wp_get_attachment_image_src( $attachment_id, 'full' );
	
	//if something went wrong, bail
	if( !is_array( $att_src_array ) ) { return false; }
	
	//the width of the image in pixels
	$width = absint( $att_src_array[1] );
	
	//if something went wrong, bail
	if( empty( $width ) ) { return false; }
	
	//the height of the image in pixels
	$height = absint( $att_src_array[2] );

	//if something went wrong, bail
	if( empty( $height ) ) { return false; }
	
	//the threshold_width is the minimum width for the image in order to be considered pano				 
	$threshold_width = $min_ratio * $height;
	
	//if the image is wider than the threshold, it's pano
	if( $width > $threshold_width ) { return true; }
	
	return false;
}
?>