大部分轉換(除了翻轉)都會總是修改輸入圖像。例如,如果您指定rotation_range
,從源代碼:
theta = np.pi/180 * np.random.uniform(-self.rotation_range, self.rotation_range)
這是不可能的隨機數將完全0
有沒有打印出應用於轉換的金額方便的方法每張圖片。您必須修改源代碼並在ImageDataGenerator.random_transform()
中添加一些打印功能。
如果您不想觸摸源代碼(例如,在共享機器上),則可以擴展ImageDataGenerator
並覆蓋random_transform()
。
import numpy as np
from keras.preprocessing.image import *
class MyImageDataGenerator(ImageDataGenerator):
def random_transform(self, x, seed=None):
# these lines are just copied-and-pasted from the original random_transform()
img_row_axis = self.row_axis - 1
img_col_axis = self.col_axis - 1
img_channel_axis = self.channel_axis - 1
if seed is not None:
np.random.seed(seed)
if self.rotation_range:
theta = np.pi/180 * np.random.uniform(-self.rotation_range, self.rotation_range)
else:
theta = 0
if self.height_shift_range:
tx = np.random.uniform(-self.height_shift_range, self.height_shift_range) * x.shape[img_row_axis]
else:
tx = 0
if self.width_shift_range:
ty = np.random.uniform(-self.width_shift_range, self.width_shift_range) * x.shape[img_col_axis]
else:
ty = 0
if self.shear_range:
shear = np.random.uniform(-self.shear_range, self.shear_range)
else:
shear = 0
if self.zoom_range[0] == 1 and self.zoom_range[1] == 1:
zx, zy = 1, 1
else:
zx, zy = np.random.uniform(self.zoom_range[0], self.zoom_range[1], 2)
transform_matrix = None
if theta != 0:
rotation_matrix = np.array([[np.cos(theta), -np.sin(theta), 0],
[np.sin(theta), np.cos(theta), 0],
[0, 0, 1]])
transform_matrix = rotation_matrix
if tx != 0 or ty != 0:
shift_matrix = np.array([[1, 0, tx],
[0, 1, ty],
[0, 0, 1]])
transform_matrix = shift_matrix if transform_matrix is None else np.dot(transform_matrix, shift_matrix)
if shear != 0:
shear_matrix = np.array([[1, -np.sin(shear), 0],
[0, np.cos(shear), 0],
[0, 0, 1]])
transform_matrix = shear_matrix if transform_matrix is None else np.dot(transform_matrix, shear_matrix)
if zx != 1 or zy != 1:
zoom_matrix = np.array([[zx, 0, 0],
[0, zy, 0],
[0, 0, 1]])
transform_matrix = zoom_matrix if transform_matrix is None else np.dot(transform_matrix, zoom_matrix)
if transform_matrix is not None:
h, w = x.shape[img_row_axis], x.shape[img_col_axis]
transform_matrix = transform_matrix_offset_center(transform_matrix, h, w)
x = apply_transform(x, transform_matrix, img_channel_axis,
fill_mode=self.fill_mode, cval=self.cval)
if self.channel_shift_range != 0:
x = random_channel_shift(x,
self.channel_shift_range,
img_channel_axis)
if self.horizontal_flip:
if np.random.random() < 0.5:
x = flip_axis(x, img_col_axis)
if self.vertical_flip:
if np.random.random() < 0.5:
x = flip_axis(x, img_row_axis)
# print out the trasformations applied to the image
print('Rotation:', theta/np.pi * 180)
print('Height shift:', tx/x.shape[img_row_axis])
print('Width shift:', ty/x.shape[img_col_axis])
print('Shear:', shear)
print('Zooming:', zx, zy)
return x
我只是在函數的末尾添加了5個print
s。其他行從原始源代碼複製並粘貼。 現在你可以用,例如使用它,
gen = MyImageDataGenerator(rotation_range=15,
width_shift_range=0.1,
height_shift_range=0.1,
zoom_range=0.5)
flow = gen.flow_from_directory('data', batch_size=1)
img = next(flow)
,看到這樣的印在終端上的信息:
Rotation: -9.185074669096467
Height shift: 0.03791625365979884
Width shift: -0.08398553078553198
Shear: 0
Zooming: 1.40950509832 1.12895574928
哇,這真的很有幫助。謝謝! – doogFromMT