Override content image generator to strip SVG images in TSF.

override-content-image-generator.php

<?php
// Don't include the PHP tag is PHP is already active


add_filter( 'the_seo_framework_image_generation_params', function( $args ) {

	if ( isset( $args['cbs']['content'] ) ) {
		$args['cbs']['content'] = 'my_content_image_generator';
	}

	return $args;
});

function my_content_image_generator( $args = null, $size = 'full' ) {

	$tsf = \the_seo_framework();

	if ( null === $args ) {
		if ( $tsf->is_singular() ) {
			$content = $tsf->get_post_content();
		}
	} else {
		if ( $args['taxonomy'] ) {
			$content = '';
		} else {
			$content = $tsf->get_post_content( $args['id'] );
		}
	}

	$matches = [];

	// strlen( '<img src=a>' ) === 11; yes, that's a valid self-closing tag with a relative source.
	if ( strlen( $content ) > 10 && false !== stripos( $content, '<img' ) ) {
		preg_match_all(
			'/<img[^>]+src=(\"|\')?([^\"\'>\s]+)\1?.*?>/mi',
			$content,
			$matches,
			PREG_SET_ORDER
		);
	}

	if ( $matches ) {
		foreach ( $matches as $match ) {
			// Skip SVG files...
			if ( false !== strpos( pathinfo( $match[2], PATHINFO_EXTENSION ), 'svg' ) ) continue;
			// Assume every URL to be correct? Yes. WordPress assumes that too.
			yield [
				'url' => $match[2] ?: '',
				'id'  => 0,
			];
		}
	} else {
		yield [
			'url' => '',
			'id'  => 0,
		];
	}
}