There seems to be a bug in Aspose Imaging 17.11.0 for Java.
Loading an image with
Image image = Image.load(inputStream);
and then querying the fileformat with
works for JPEG images but fails for PNG images, as getFileFormat() returns 0 instead of the correct identification number. Despite of that the image can be read and is correctly created. Please see attached image from debugger.
PastedGraphic-1.png (73.5 KB)