I've been using FBReader so far for reading e-books, but my problem with it is how it handles images. Whenever there's an image, it isn't displayed until all of it can be displayed (i.e. it won't show if you haven't scrolled down far enough) and scrolling isn't smooth because the image is treated as one line.

Is there a way to change this so that it displays the partially visible images?

If there is not a way to change this, I am open to software suggestions to use as an alternative (I'm using Linux).

I have already tried Calibre, but I find that it's too bloated. It takes ages to start up, and I don't want a directory for all my e-books...