Created as below to show the variation of the JPEG compression artifacts: convert -quality 90 Felis_silvestris_silvestris_small_gradual_decrease_of_quality.png Felis_silvestris_silvestris_small_gradual_decrease_of_quality.jpg compare Felis_silvestris_silvestris_small_gradual_decrease_of_quality.png Felis_silvestris_silvestris_small_gradual_decrease_of_quality.jpg -compose difference Felis_silvestris_silvestris_small_gradual_decrease_of_quality-difference.png