Iterate Images form uploads folder

wp-scan-images.php

<?php

// Scan images from uoloads folder including sub-folders.
function fp_scan_images() {
	try {
		$images     = [];
		$upload_dir = wp_upload_dir();
		$directory  = $upload_dir['basedir'];

		// Recursive scan with FileSystemIterator
		$iterator = new RecursiveIteratorIterator(
			new RecursiveDirectoryIterator( $directory, FilesystemIterator::SKIP_DOTS )
		);
		
		if(empty($iterator)) return;


		foreach ( $iterator as $file ) {
			if ( $file->isFile() && in_array( strtolower( $file->getExtension() ), [ 'jpg', 'jpeg', 'png' ], true ) ) {
				$images[] = str_replace( $directory, $upload_dir['baseurl'], $file->getPathname() );
			}
		}

		$images = ! empty( $images ) ? array_unique( $images ) : [];
		return $images;
	} catch ( Exception $e ) {
		error_log( 'FlyingPress: Error scaning images - ' . $e->getMessage() );
		return 0;
	}
}