I would like to use the HTML or Advanced HTML block on the welcome page to display an image for visitors. However when doing so it does not expand to the size of the image and only displays some of it while allowing scrolling within the the block. Is there anyway to expand the block to the size of the image or another block type or plugin that can be used to display a larger image? The image will fit in the right column width but is taller than the HTML and Advanced HTML block seem to allow for. Anyone have any advice?
You will have to know PHP.
Clone the Adv HTML block (block_htmlplus.php and rename it.
Find the code within the new block or in the CSS that defines the height and change it to either a fixed height or dynamic.
Use that block for your image placement.