An ALT label will work with newer browsers. Image Maps are not labeled. This is another type of image that needs to be labeled. Tables present special problems to some screen reading programs for people who are blind or have low vision. There are a variety of solutions.
Busy backgrounds make text hard to read.
Busy background images can make text hard to read for persons with visual, learning or cognitive disabilities. If a background image is used it should remain well in the background and there should be maximum contrast between the type and the background. This is also true when a plain color background is used with colored text. The goal is for maximum contrast and readability. It is best also to view your page with different browsers on different platforms.