gistfile1.c

            uint8 *fourchan = (uint8*) malloc(sizeof(uint8) * width * height * 4);
            short cur;
            short *subscript = (short*) imgData;
            for (int i = 0; i < width * height; i++) {
                cur = (subscript[i] + 1000) / (int) pow(2., sizeof(short)/2.);
                fourchan[i*4] = (uint8) cur;
            }