}
                final int samplingWidth = width / fessConfig.getThumbnailHtmlImageThumbnailWidthAsInteger();
                final int samplingHeight = height / fessConfig.getThumbnailHtmlImageThumbnailHeightAsInteger();
                param.setSourceSubsampling(samplingWidth <= 0 ? 1 : samplingWidth, samplingHeight <= 0 ? 1 : samplingHeight, 0, 0);

     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     * @throws NumberFormatException When the property is not integer.
     */
    Integer getThumbnailHtmlImageThumbnailHeightAsInteger();

    /**
     * Get the value for the key 'thumbnail.html.image.format'. <br>
     * The value is, e.g. png <br>