Method and device for displaying image
A method for displaying an image is provided in which an optimal lighting pattern is selected so as to reduce pseudo contours and flickers. In an image display for reproducing halftones by a subframe technique, a frame is converted into plural subframes. For each of pixels of a display screen, the lighting pattern that is a combination of on and off of the subframes are determined in accordance with a frame data value of the noted pixel, a lighting pattern of the noted pixel in the past frame and the lighting pattern determined for the peripheral pixel located in the vicinity of the noted pixel and having the same display color as the noted pixel.
1. A method for displaying an image in which a halftone is reproduced by a subframe technique of converting a frame into a plurality of subframes, the method comprising:
determining a lighting pattern that is a combination of on and off of the subframes for each of plural pixels of a display screen in accordance with a frame data value of a noted pixel, a lighting pattern of the noted pixel in a past frame and a lighting pattern determined for a peripheral pixel that is located in a vicinity of the noted pixel and has the same display color as the noted pixel, wherein:
intensity values of Fourier components of the difference between the light emission waveform indicated by the lighting pattern in the past frame and a target light emission waveform indicated by the frame data value; and intensity values of Fourier components of a light emission distribution error between the peripheral pixel and the noted pixel are determined so that a sum of the intensities after being weighted becomes a minimum.
2. A method as recited in claim 1 , wherein the weight of the Fourier components having a frequency above a flicker frequency is set to zero among the Fourier components of the difference between the light emission waveform indicated by the lighting pattern in the past frame and the target light emission waveform indicated by the frame data value.
3. A method as recited in claim 1 , wherein the determining a lighting pattern uses only the components corresponding to the period twice the pixel pitch among the Fourier components of the light emission distribution error between the peripheral pixel and the noted pixel.
4. A method for displaying an image in which a halftone is reproduced by a subframe technique of converting a frame into a plurality of subframes, the method comprising:
determining a lighting pattern that is a combination of on and off of the subframes for each of plural pixels of a display screen in accordance with a frame data value of a noted pixel, a lighting pattern of the noted pixel in a past frame and a lighting pattern determined for a peripheral pixel that is located in a vicinity of the noted pixel and has the same display color as the noted pixel, wherein:
a lighting pattern is regarded as a coordinate value so that the sum of a distance to the lighting pattern of the past frame and a distance to the lighting pattern determined for the peripheral pixel becomes a minimum.
5. A method for displaying an image in which a halftone is reproduced by a subframe techniciue of converting a frame into a plurality of subframes, the method comprising:
determining a lighting pattern that is a combination of on and off or the subframes for each of plural pixels of a display screen in accordance with a frame data value of a noted pixel, a lighting pattern of the noted pixel in a past frame and a lighting pattern determined for a peripheral pixel that is located in a vicinity of the noted pixel and has the same display color as the noted pixel, wherein:
only a part of the plurality of subframes is noted, the lighting pattern of the past frame and the lighting pattern determined for the peripheral pixel are referred, and the lighting pattern is regarded as a coordinate value, so that a sum of a distance to the lighting pattern in the past frame and a distance to the lighting pattern determined for the peripheral pixel becomes a minimum value.