将列表转换为 numpy 数组时出现内存错误

Question

我总共有大约 7000 张图像从中提取了 HoG 特征。然后我想将列表转换为 np 数组以进行进一步处理。但在转换过程中出现内存错误。

这是我的代码的相关部分：

from skimage import data, io, filter, color, exposure
from skimage.feature import hog
from skimage.transform import resize
import matplotlib.pyplot as plt
import numpy as np

tmp_hogs = [] # this is the list I need to convert into a numpy array
for group in samplegroups:
    for myimg in group:
        curr_img = np.array(myimg, dtype=float)
        imgs.append(curr_img)
        fd, hog_image = hog(curr_img, orientations=8, pixels_per_cell=(4, 4),
                 cells_per_block=(1, 1), visualise=True, normalise=True)
        tmp_hogs.append(fd)

img_hogs = np.array(tmp_hogs, dtype =float) 

我得到的错误是：

Exception in thread Thread-1:
Traceback (most recent call last):
  File "C:\Users\app\anacondasoftware\lib\threading.py", line 810, in __bootstrap_inner
    self.run()
  File "C:\Users\app\anacondasoftware\lib\site-packages\spyderlib\widgets\externalshell\monitor.py", line 582, in run
    already_pickled=True)
  File "C:\Users\app\anacondasoftware\lib\site-packages\spyderlib\utils\bsdsocket.py", line 45, in write_packet
    nsend -= temp_fail_retry(socket.error, sock.send, sent_data)
  File "C:\Users\app\anacondasoftware\lib\site-packages\spyderlib\utils\bsdsocket.py", line 25, in temp_fail_retry
    return fun(*args)
error: [Errno 10054] An existing connection was forcibly closed by the remote host

Traceback (most recent call last):
  File "C:\Users\app\Documents\Python Scripts\gbc_carclassify.py", line 63, in <module>
    img_hogs = np.array(tmp_hogs, dtype =float) 
MemoryError

我该如何解决？

Answer 1

对于 RGB 或 RGBA 图像，每个值只需要 8 位，而使用 float 时，每个值分配 64 位。尝试改用np.uint8：

img_hogs = np.array(tmp_hogs, dtype=np.uint8)