1. A semiconductor device having an image-processing function, comprising: an image processor processing image data and outputting first processed data and second processed data; a data combination circuitry combining the first processed data and the second processed data and outputting combined data; an output buffer circuit into which the combined data are transferred from the data combination circuitry; and a data distribution circuitry into which the combined data are transferred from the output buffer circuit, wherein the data distribution circuitry is configured to output first output data in a first form or second output data in a second form, wherein, in the first form, the first processed data and the second processed data are separated, wherein, in the second form, the first processed data and the second processed data are combined.