Set the post meta field to selected image choices URL

gform_set_post_meta_to_image_choices_urls.php

<?php
add_filter( 'gform_post_data', 'gform_set_post_meta_to_image_choices_urls', 10, 3 );
function gform_set_post_meta_to_image_choices_urls( $post_data, $form, $entry ) {

	foreach( $form['fields'] as $field ) {

		$value = RGFormsModel::get_lead_field_value( $entry, $field );
		
		if ( $field->type != 'post_custom_field' || !property_exists($field, 'postCustomFieldName') || empty($field->postCustomFieldName) || !property_exists($field, 'imageChoices_enableImages') || empty($field->imageChoices_enableImages) || !isset($post_data['post_custom_fields'][$field->postCustomFieldName]) ) {
			// if it's not a custom field, doesn't use image choices, or no custom field name configured, skip
			continue;
		}		
		
		$images = [];
		$i = 1;
		foreach( $field->choices as $choice ) {
			if ( is_array($value) ) {
				$key = $field->id . '.' . $i;
				if ( !isset($value[$key]) || $value[$key] != $choice['value'] || !isset($choice['imageChoices_imageID']) || empty($choice['imageChoices_imageID']) ) {
					// if this isn't the selected choice, skip
					$i++;
					continue;
				}
			}
			else if ( $value == '' || $value != $choice['value'] || !isset($choice['imageChoices_imageID']) || empty($choice['imageChoices_imageID']) ) {
				// if this isn't the selected choice, skip
				$i++;
				continue;
			}

			$image_id = $choice['imageChoices_imageID'];
			$image_src = wp_get_attachment_image_src( $image_id, 'large' );// set to desired size
			$images[] = $image_src[0];
			$i++;
		}
		
		if ( count($images) == 0 ) {
			continue;
		}

		$post_data['post_custom_fields'][$field->postCustomFieldName] = (count($images) > 1) ? implode("&#44;", $images) : $images[0];

	}

	return $post_data;
}