              logger.debug("Folder does not exist")
              return None
          files = [os.path.join(imgpath, f)
                   for f in os.listdir(imgpath) if f.lower().endswith((".png", ".jpg"))]
          logger.trace("Image files: %s", files)
          return files
  
      def load_latest_preview(self, thumbnail_size, frame_dims):
          """ Load the latest preview image for extract and convert """
          logger.trace("Loading preview image: (thumbnail_size: %s, frame_dims: %s)",
 
</s> remove         logger.trace("Loading preview image: (thumbnail_size: %s, frame_dims: %s)",
 </s> add         logger.debug("Loading preview image: (thumbnail_size: %s, frame_dims: %s)", </s> remove         logger.trace("Getting images: '%s'", imgpath)
 </s> add         logger.debug("Getting images: '%s'", imgpath) </s> remove         if not imagefiles or len(imagefiles) == 1:
 </s> add         gui_preview = os.path.join(self.pathoutput, ".gui_preview.jpg")
        if not imagefiles or (len(imagefiles) == 1 and gui_preview not in imagefiles): </s> remove         logger.trace("Loading Training preview images")
 </s> add         logger.debug("Loading Training preview images") </s> remove         logger.trace("display shape: %s", display.shape)
 </s> add         logger.debug("display shape: %s", display.shape)
        logger.debug("Image files: %s", files)
              logger.debug("Folder does not exist")
              return None
          files = [os.path.join(imgpath, f)
                   for f in os.listdir(imgpath) if f.lower().endswith((".png", ".jpg"))]
        logger.debug("Image files: %s", files)
          return files
  
      def load_latest_preview(self, thumbnail_size, frame_dims):
          """ Load the latest preview image for extract and convert """
          logger.trace("Loading preview image: (thumbnail_size: %s, frame_dims: %s)",
keep keep keep keep replace keep keep keep keep keep
 GUI: Preview for convert

Display preview when outputting to a stream container (e.g. video, gif) 
lib/gui/utils.py