test_data=np.random.randint(0,256,size=(400,800,3))
for i in range(400):
for j in range(800):
    mn = np.mean(test_data[i,j])
    for k in range(3):
        test_data[i,j,k]=mn

test_data[i,j,0]=test_data[i,j,0]*0.2
test_data[i,j,1]=test_data[i,j,1]*0.5
test_data[i,j,2]=test_data[i,j,2]*0.3