Sizing Full-Page Images: Why is there a white gap at the bottom?

Full-page images with bleed should precisely match the proportions of the printed page size, plus an additional .125 inch width and .25 inch height. This will ensure that there's no white space beneath the image. If you require assistance in determining the dimensions of full-page images with bleed, we have a calculator in this tutorial: https://www.atticus.io/calculate-image-size-for-print-and-ebooks/