final BufferedImage thumbnail = new BufferedImage(thumbnailWidth, thumbnailHeight, image.getType());
                thumbnail.getGraphics().drawImage(image.getScaledInstance(thumbnailWidth, thumbnailHeight, Image.SCALE_AREA_AVERAGING), 0,
                        0, thumbnailWidth, thumbnailHeight, null);
                ImageIO.write(thumbnail, fessConfig.getThumbnailHtmlImageFormat(), outputFile);