Full width on home page images

Hi,

I wanted to know how to make an image use full width of the page?

When I add an image and edit the row and make it use full width, the image still is not using the full width of the page. It still has some margins between the image above, below and in the left and right side.(See image 1 attached)

I would like to know how to make and image use the same width that my slider is using. ( see image)