in thumbnails4j-pdf/src/main/java/co/elastic/thumbnails4j/pdf/PDFThumbnailer.java [84:96]
private List<BufferedImage> getThumbnails(PDDocument document, List<Dimensions> dimensions) throws IOException {
List<BufferedImage> results = new ArrayList<>();
document.setResourceCache(new NullCache());
Integer thumbnailPageIndex = thumbnailPageIndex(document);
if (thumbnailPageIndex != null){
BufferedImage image = new PDFRenderer(document).renderImage(thumbnailPageIndex, 0.5f);
for(Dimensions singleDimension: dimensions) {
results.add(ThumbnailUtils.scaleImage(image, singleDimension));
}
}
return results;
}