| # Copyright 2015 The Chromium OS Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| """Defines type check methods that can be used with safetynet.""" |
| import numpy as np |
| |
| |
| def Image(instance): |
| """Returns True if instance is a 2D image.""" |
| if not isinstance(instance, np.ndarray): |
| return False |
| if len(instance.shape) < 2 or len(instance.shape) > 3: |
| return False |
| if len(instance.shape) == 3: |
| if instance.shape[2] < 2 or instance.shape[2] > 4: |
| return False |
| return True |
| |
| |
| def RGBImage(instance): |
| """Returns True if instance is a 2D RGB image.""" |
| if not Image(instance): |
| return False |
| shape = instance.shape |
| return (len(shape) == 3 and shape[2] == 3 and instance.dtype == np.float) |
| |
| |
| def RGBAImage(instance): |
| """Returns True if instance is a 2D RGBA image.""" |
| if not Image(instance): |
| return False |
| shape = instance.shape |
| return (len(shape) == 3 and shape[2] == 4 and instance.dtype == np.float) |
| |
| |
| def GrayscaleImage(instance): |
| """Returns True if instance is a 2D grayscale float image.""" |
| if not Image(instance): |
| return False |
| shape = instance.shape |
| return (len(shape) == 2 and instance.dtype == np.float) |
| |
| |
| def BinaryImage(instance): |
| """Returns True if instance is a 2D binary image.""" |
| if not Image(instance): |
| return False |
| shape = instance.shape |
| return (len(shape) == 2 and instance.dtype == np.bool) |
