Brief example showing how to remove a filter (in this case, the "Sharing" buttons that JetPack outputs at the end of content) within WordPress.

remove-jetpack-sharing-filter.php

<?php
function output_featured_image() {
	echo '<figure class="featured-image">';
	the_post_thumbnail( 'archive-feature', array( 'class' => 'alignnone' ) );
  
	// First, check to see if the Sharing buttons are supposed to display on content or excerpt
	// Remove those sharing buttons if they are
	$sharecontent = false;
	$shareexcerpt = false;
	if ( has_filter( 'the_content', 'sharing_display' ) ) {
		$sharecontent = true;
		remove_filter( 'the_content', 'sharing_display', 19 );
	}
	if ( has_filter( 'the_excerpt', 'sharing_display' ) ) {
		$shareexcerpt = true;
		remove_filter( 'the_excerpt', 'sharing_display', 19 );
	}
	
	echo '<figcaption>';
	
	// Output the content you want to output here, without the sharing_display callback being called
	// In this case, I am outputting the image "caption" and the image "description" 
	// with the excerpt & content filters applied, respectively
	if ( ! empty( $image->post_excerpt ) ) {
		echo '<div class="photo-credit">';
		echo apply_filters( 'the_excerpt', $image->post_excerpt );
		echo '</div>';
	}
	if ( ! empty( $image->post_content ) ) {
		echo '<div class="featured-image-caption">';
		echo apply_filters( 'the_content', $image->post_content );
		echo '</div>';
	}
	
	echo '</figcaption>';
	
	// Now, if the callback was registered to begin with, we need to put it back
	if ( $sharecontent ) {
		add_filter( 'the_content', 'sharing_display', 19 );
	}
	if ( $shareexcerpt ) {
		add_filter( 'the_excerpt', 'sharing_display', 19 );
	}
	
	echo '</figure>';
}