A presentation application for masking portions of an object, such as the background of an image, is provided. The presentation application may provide a background removal tool that allows a user to define an initial point in the background of the object. The presentation application may establish an initial background color based on the initial point, and may compute and automatically adjust a color tolerance of the background color based on the distance that a user-controlled cursor is from the initial point. Using a seed-fill algorithm, the presentation application can select a contiguous portion of the object for masking that includes the initial point and surrounding pixels that are within the background color tolerance. To smoothen the edges of the contiguous portion, the presentation application can convert the portion to a vector graphic before making the object.