Mentalrayのnormal画像(32bit float)を読み込む

gistfile1.py

def read_image(img_file):
    with open(img_file, 'rb') as img:
        (format, nll, xres, yres, verson) = unpack('>BBHHH', img.read(8))
        
        pixels = np.zeros([yres, xres, 3]) # y,xでアクセスする
        
        for iy in range(yres):
            line = unpack('>{0}f'.format(xres*3), img.read(4*xres*3))
            for lx, ix in enumerate(range(0, xres*3, 3)):
                pixels[iy][lx] = line[ix:ix+3]