Neos\Media\ViewHelpers\ImageViewHelper::initializeArguments PHP Method

    public function initializeArguments()
    {
        parent::initializeArguments();
        $this->registerUniversalTagAttributes();
        $this->registerTagAttribute('alt', 'string', 'Specifies an alternate text for an image', true);
        $this->registerTagAttribute('ismap', 'string', 'Specifies an image as a server-side image-map. Rarely used. Look at usemap instead', false);
        $this->registerTagAttribute('usemap', 'string', 'Specifies an image as a client-side image-map', false);
        // @deprecated since 2.0 use the "image" argument instead
        $this->registerArgument('asset', AssetInterface::class, 'The asset to be rendered - DEPRECATED, use the "image" argument instead', false);
    }