Display driving method and apparatus

A display driving method which drives a display to make a gradation display on a screen of the display depending on a length of a sustain time interval in each of sub fields forming one field, where the field is a time interval in which an image is displayed and the sustain time interval is equal to a light emission time and determines a luminance level, said display driving method comprising:

• detecting at least one image feature from an amount of motion of an input image signal having “n” gradation levels, a luminance level of the input image signal at which the sub fields having a light emission state greatly change on a time base, and an edge portion of the input image signal;
• converting the input image signal into a first display information signal having “a” gradation levels satisfying a≦n or, into a second display information signal having “b” gradation levels satisfying b<a, depending on the detected image feature, and outputting the first or second display information signal as an output display information signal;
• and
• driving the display based on the output display information signal so as to make the gradation display on the screen of the display.