Patent ID: 8587605

Claim:
An image processing device, which combines a first display screen and a second display screen, which are display screens expressed in index color expression in which pixel colors of pixels are indicated by color codes selected and combined as necessary from among R, G, and B, the image processing device comprising: a memory device for storing therein a first look-up table and a second look-up table, wherein the first look-up table shows association between the color codes and RGB expression for the pixel colors of the pixels constituting the first display screen, and includes values respectively indicating intensities of R, G, and B, and an α value indicating transmittance, and the second look-up table shows association between the color codes and RGB expression for the pixel colors of the pixels constituting the second display screen, and includes values respectively indicating intensities of R, G, and B, and an α value indicating transmittance; and creating means for creating a composite screen in the index color expression by combining the first display screen and the second display screen in such a manner that a display effect obtainable by superimposing the first display screen and the second display screen is obtained, the creating means including: look-up table creating means for creating, from the first look-up table and the second look-up table, a third look-up table for showing association between color codes and RGB expression for pixel colors of pixels constituting the composite screen; changing means for changing the third look-up table in such a manner that values respectively corresponding to the values respectively indicating intensities of R, G, and B, and the α value of a certain color code in the first look-up table are changed; updating means for rewriting the third look-up table in such a manner that, based on the values changed by the changing means, values respectively corresponding to the values respectively indicating intensities of R, G, and B, and the α value in the second look-up table are rewritten so as to obtain color expression corresponding to colors obtainable by superimposing the first display screen and the second display screen; and composite screen creating means for creating the composite screen by referring to the third look-up table thus rewritten by the updating means.