tensorflow 图像数据处理（一）

原图式样：

代码：

# -*- coding: utf-8 -*-
"""
@author: tz_zs
图片的编码、解码、随机截取图像
"""
import matplotlib.pyplot as plt
import tensorflow as tf

image_raw_data = tf.gfile.FastGFile("picture.jpg", 'rb').read()

with tf.Session() as sess:
# 解码
image_data = tf.image.decode_jpeg(image_raw_data)

print(image_data.eval())
plt.imshow(image_data.eval())
plt.show()#图1
"""
[[[ 94 131  53]
[ 87 125  48]
[ 83 121  48]
...,
[ 29  63  13]
[ 31  65  14]
[ 34  69  15]]

[[106 150  65]
[100 143  61]
[ 94 138  59]
...,
[ 30  64  13]
[ 32  67  13]
[ 34  69  15]]

[[111 161  72]
[103 153  66]
[ 97 149  64]
...,
[ 33  65  15]
[ 34  67  14]
[ 35  68  13]]

...,
[[250 250 250]
[250 250 250]
[251 251 251]
...,
[ 13  26   8]
[ 14  25   9]
[ 12  23   9]]

[[248 248 248]
[249 249 249]
[250 250 250]
...,
[ 14  29  10]
[ 15  28  10]
[ 14  27  10]]

[[250 250 250]
[251 251 251]
[249 249 249]
...,
[ 16  31  10]
[ 16  31  12]
[ 16  29  11]]]
"""
# image_data = tf.image.convert_image_dtype(image_data, dtype=tf.float32)  # uint8→float32

# 编码
# encode_image = tf.image.encode_jpeg(image_data)# 接收的是 Tensor型uint8
# with tf.gfile.GFile("output.jpg", 'wb') as f:
#     f.write(encode_image.eval())

# 缩小
image_data = tf.image.resize_images(image_data, [180, 267], method=1)
plt.imshow(image_data.eval())
plt.show()#图2
# print(tf.shape(image_data).eval())  # [180 267   3]

# 随机截取图像
boxes = tf.constant([[[0.05, 0.05, 0.9, 0.7], [0.35, 0.47, 0.5, 0.56]]])
'''
print(boxes)
Tensor("Const:0", shape=(1, 2, 4), dtype=float32)
print(boxes.eval())
[[[0.05        0.05        0.89999998  0.69999999]
[0.34999999  0.47        0.5         0.56]]]
'''
begin, size, bbox_for_draw = tf.image.sample_distorted_bounding_box(tf.shape(image_data), bounding_boxes=boxes)

print(begin.eval())
print(size.eval())
print(bbox_for_draw.eval())
'''
[ 9 46  0]
[161 139  -1]
[[[ 0.07777778  0.40449437  0.77777779  0.90262175]]]
'''
image_data = tf.slice(image_data, begin, size)
plt.imshow(image_data.eval())
plt.show()#图3

图1：

图2：

图3：