WordPress at a glance
function is not described

stream_preview_image() WP 1.0

Streams image in post to browser, along with enqueued changes in $_REQUEST['history']

No Hooks.

Return

true/false.

Usage

stream_preview_image( $post_id );
$post_id(int) (required)

Code of stream preview image: wp-admin/includes/image-edit.php VER 5.0.3

<?php
function stream_preview_image( $post_id ) {
	$post = get_post( $post_id );

	wp_raise_memory_limit( 'admin' );

	$img = wp_get_image_editor( _load_image_to_edit_path( $post_id ) );

	if ( is_wp_error( $img ) ) {
		return false;
	}

	$changes = !empty($_REQUEST['history']) ? json_decode( wp_unslash($_REQUEST['history']) ) : null;
	if ( $changes )
		$img = image_edit_apply_changes( $img, $changes );

	// Scale the image.
	$size = $img->get_size();
	$w = $size['width'];
	$h = $size['height'];

	$ratio = _image_get_preview_ratio( $w, $h );
	$w2 = max ( 1, $w * $ratio );
	$h2 = max ( 1, $h * $ratio );

	if ( is_wp_error( $img->resize( $w2, $h2 ) ) )
		return false;

	return wp_stream_image( $img, $post->post_mime_type, $post_id );
}