Average pixel luminosity is calculated for each frame comprising a content item. For each pair of adjacent frames, an IFD is calculated. The IFD represents the difference between a baseline pixel luminosity associated with each of the two frames. An initial set of cut frames is selected based on IFD values that are less than a minimum value IFDmin, or that are greater than a maximum value IFDmax. The positions of these initial cut frames are optimized using a numerical optimization technique that favors removal of frames corresponding to IFD extrema, but that also attempts to maintain a minimum time gap between cut frames. Selecting frames for removal is approached as a constraint minimization problem. Once an optimized set of cut frames is established, audio is cut and crossfaded in a temporal window surrounding cut frame positions.