Image processing method and display device using the same

Disclosed is an image processing method, in which three primary color data of an input RGB data format are rendered on a display panel according to a sub-pixel structure of the display panel, the display panel having as many G sub-pixels as the display resolution input G data and as many R and B sub-pixels as half the display resolution of input R and B data, respectively, the method comprising: (A) separating the R and B data and the G data from the input data; (B) loading data corresponding to respective odd rows of gamma-converted R and B data, and storing data corresponding to respective even rows of the R and B data adjacent to the loaded odd rows; (C) loading two R data of the even row, along with two R data of the odd row corresponding to a first display position, so as to form a 2x2 R pixel area, and loading two B data of the even row, along with two B data of the odd row corresponding to a second display position, so as to form a 2x2 B pixel area; (D) computing the sharpness of the corresponding display data by comparing the data in each of the R and B pixel areas column by column and row by row; (E) computing the luminance of the display data by taking the average value of the data corresponding to the odd row of each of the R and B pixel areas; (F) determining the gray scale value of output R data by adding the sharpness to the luminance of the R data, and determining the gray scale value of output B data by adding the sharpness to the luminance of the B data; and (G) combining the inverse-gamma-converted R and B data and the input G data and then outputting the combined data according to the sub-pixel structure of the display panel.