| 摘要 |
PROBLEM TO BE SOLVED: To generate the image signal of a superimposed image in a way such that a background map image is seen through under a graphic image by generating the signal of the superimposed image, where a gradation value is converted based on a specific equation respectively on a part, where one image is not superimposed on other image and on a part where one image is superimposed on other image. SOLUTION: The signal of a superimposed image is generated, where a gradation value is converted for a part in which other image is not superimposed on one image based on the equation C=B, and for a part in which other image is superimposed on one image based on the equation C=(1-α).A+α.B, where A is the gradation value of one image, B is the gradation value of the other image, C is the gradation of a superimposed image, andαis a transparency adjustment value (0<=α<=1). Anαvalue generating circuit 6 of this device generates a valueαwhich corresponds to the operation of a transparency switch 5 and outputs it to a look-up table(LUT) 4. The LUT 4 references a synthesis conversion table, corresponding to theαvalue to generate an image resulting in a graphics image which is superposed on a map image. |
