Optical display system and method, active and passive dithering using birefringence, color image superpositioning and display enhancement with phase coordinated polarization switching

A method of controlling contrast of a display image of a display apparatus capable of displaying color within a predetermined grey range having a predetermined number of discrete shades of grey, wherein an input image signal uses a first number of discrete shades of grey that is less than the predetermined number of discrete shades of grey of the display apparatus in a range less than the predetermined grey range when an image corresponding to the input image signal is a bright image or a dim image, the display apparatus including an illuminating light source and a computer control, the method comprising:

• processing brightness information and color information of the input image signal to determine the first number of discrete shades of grey;
• and
• changing the first number of discrete shades of grey to a second number of discrete shades of grey greater than the first number of discrete shades of grey while adjusting the amount of light from the illuminating light source if the input image is a bright image or a dim image.

A method of controlling contrast of a display image of a display apparatus including an illuminating light source and a computer control, the method comprising:

• processing brightness information and color information of an input signal and determining shades of grey used for the input signal using the computer control;
• and
• increasing the number of shades of grey used to display an image corresponding to the input signal while decreasing the amount of light if the image corresponding to the input signal is a dim image and increasing the amount of light if the image corresponding to the input signal is a bright image.

A display device for displaying an image, comprising:

• a display;
• an illuminating light source;
• a computer control, wherein the computer control receives an input signal including brightness and color information, determines shades of grey used for the input signal and increases a number of shades of grey used to display an image on the display corresponding to the input signal while increasing an amount of light from the illuminating light source if the brightness is high and decreasing an amount of light from the illuminating light source if the brightness is low.

A method of controlling contrast of a display image of a display apparatus including an illuminating light source and a computer control, the method comprising:

• processing brightness information and color information and determining shades of grey used for an input signal using the computer control;
• and
• increasing the number of shades of grey used to display an image corresponding to the input signal while adjusting the amount of light if the image corresponding to the input signal is a dim image or a bright image.

A display device for displaying an image, comprising:

• a display;
• an illuminating light source;
• a computer control, wherein the computer control receives an input signal including brightness and color information, determines shades of grey used for the input signal and increases a number of shades of grey used to display an image on the display corresponding to the input signal while adjusting an amount of light from the illuminating light source if the brightness is high or if the brightness is low.

A display device for displaying an image, comprising:

• a display;
• an illuminating light source having a plurality of light sources of different colors;
• a computer control, wherein the computer control receives an input signal including brightness and color information, determines shades of grey used for the input signal and increases a number of shades of grey used to display an image on the display corresponding to the input signal while increasing an amount of light from the illuminating light source if the brightness of the input image is high and decreasing an amount of light from the illuminating light source if the brightness of the input image is low.

A method of controlling contrast of a display image of a display apparatus capable of displaying color within a predetermined grey range having a predetermined number of discrete shades of grey, wherein an input image signal uses a first number of discrete shades of grey that is less than the predetermined number of discrete shades of grey of the display apparatus in a range less than the predetermined grey range, the display apparatus including an illuminating light source and a computer control, the method comprising:

• processing brightness information and color information of the input image signal to determine the first number of discrete shades of grey;
• and
• changing the first number of discrete shades of grey to a second number of discrete shades of grey greater than the first number of discrete shades of grey while adjusting the amount of light from the illuminating light source.