PDFRead just might work for you too, depending on your source text:
https://www.mobileread.com/forums/showthread.php?t=21906
According to the write-up in our wiki, it is a tool for converting primarily PDF and DJVU documents for reading on eBook devices. It does this by creating an image out of each page, enhancing the image and then collating the images in a device-specific format (supports .IMP/.RB/.OEB/.LRF/.PRC/.HTML)