The disadvantage is that each scan takes about the same amount of computation to display as a whole baseline JPEG file would. This is only true if you're actua

The disadvantage is that each scan takes about the same amount of computation to display as a whole baseline JPEG file would. This is only true if you're actually displaying each and every refinement level. If you only display the final image, progressive and baseline JPEG have about the same computational complexity. Progressive is still slower because of less efficient cache access patterns, however.