A machine may receive, from one or more sensors, first data indicating a first position of a work implement within an environment and second data indicating a second position of the work implement within the environment. Based on the first position and the second position, the machine may define a working area of the work implement. The machine may receive, from one or more cameras, image data depicting at least a portion of the environment and at least a portion an object disposed within a field of view of the one or more cameras. The machine may determine, based on the image data, that the object is located outside of the working area. Based on determining that the object is located outside of the working area, the machine may refrain from causing output of an alert indicating the presence of the object outside the working area.