chunks.py 文件源码

def encode_jpeg(arr):
    assert arr.dtype == np.uint8

    # simulate multi-channel array for single channel arrays
    if len(arr.shape) == 3:
        arr = np.expand_dims(arr, 3) # add channels to end of x,y,z

    arr = arr.transpose((3,2,1,0)) # channels, z, y, x
    reshaped = arr.reshape(arr.shape[3] * arr.shape[2], arr.shape[1] * arr.shape[0])
    if arr.shape[0] == 1:
        img = Image.fromarray(reshaped, mode='L')
    elif arr.shape[0] == 3:
        img = Image.fromarray(reshaped, mode='RGB')
    else:
        raise ValueError("Number of image channels should be 1 or 3. Got: {}".format(arr.shape[3]))

    f = io.BytesIO()
    img.save(f, "JPEG")
    return f.getvalue()