1. A system, comprising: one or more processors; and a memory coupled to the one or more processors and storing program instructions executable by the one or more processors to implement: accessing data representing an image; generating a suggested seam carving mask for the image, wherein a seam carving mask comprises data representing one or more pixels to be protected from or targeted by an image editing operation; displaying the suggested seam carving mask as an overlay of the image; in response to receiving user input, modifying the suggested seam carving mask, wherein said modifying comprises adding data representing one or more additional pixels to the suggested seam carving mask or removing data representing at least a subset of the one or more pixels from the suggested seam carving mask; and storing data representing the modified seam carving mask for use in a subsequent image editing operation directed to the image.