您的图像格式可能不受支持或图像文件已损坏。例如，如果您通过 google 或 bing 下载图像，这种情况经常发生。当我经常这样做时，我开发了一个下面提供的函数，它检查包含子目录中保存的图像的目录（如果您使用 ImageDataGenerator()，则为类目录，flow_from_directory。它检查文件是否是有效的图像文件并具有在用户定义的适当扩展名列表中指定的扩展名。代码如下所示。它有点长，因为它对输入等进行了大量检查。请注意，如果它检测到扩展名为 jfif 的文件，它会将其重命名为 jpg，因为它们是相同的格式。可以设置参数 convert_ext 以根据指定的扩展名将所有图像转换为新的图像格式，例如 'bmp' 如果保留为 None，则图像保留其原始格式。
import os
import shutil
import cv2
def check_file_extension (source_dir, good_ext_list, delete=False, convert_ext=None):
# source_dir is the directory containing the class sub directories that hold the images
# good_ext_list is a list of strings you specify as good extensions for the ImageDataGenerator
# this list should be ['jpg', 'jpeg', 'bmp', 'png', 'tiff']
# delete is a boolean, if set to True image files that have invalid extensions or are not valid
# image files will be deleted.
# the function return a list. If delete=False this is a list of all files that have invalid
# extensions or are not valid image files
# if convert_ext is set to other than None, it should be a string indicating the new image format
# the files will be converted to, for example "jpg"
processed_count=0 # will be total number of files found
good_count=0 # will be total number of valid image files found
bad_file_list=[] # will be a list of all files processed that had invalid extensions
removed_count=0 # will be the number of files deleted if delete is set to true
class_list=os.listdir(source_dir)
if len(class_list)==0:
print('directory ', source_dir, ' is empty *** Program Terminating')
return None
print('{0:^20s}{1}{2:^17s}{1}{3:^14s}{1}{4:^15s}'.format('Class Directory',' ', 'Files Processed', 'Files Verified', 'Files Removed'))
for klass in class_list:
class_path=os.path.join(source_dir, klass)
if os.path.isdir(class_path)==False:# check if this is a directory if it is not print a warning
print ('*** Warning *** there are files in ', source_dir, ' it should only contain sub directories' )
else:
class_file_count=0 # will be number of files found in the class directory
class_good_count=0 # will be the number of good files found in the class directory
class_removed_count =0
f_list=os.listdir(class_path) # get a list of files in the class directory
for f in f_list:
f_path=os.path.join(class_path,f)
if os.path.isfile(f_path)==False: # check if it is a file if it is a directory print a warning
print ('*** Warning *** there is a directory in ', class_path, ' there should only be files there')
else:
class_file_count +=1 #increment class file counter
index=f.rfind('.')
fname=f[:index]
fext=f[index+1:].lower()
if fext not in good_ext_list and fext !='jfif':
if delete:
os.remove(f_path)
class_removed_count +=1 # increment removed file counter
else:
bad_file_list.append(f_path) # don't delete but put the path in list of files with bad extensions
else:
if fext =='jfif': # if ext= jfif change it to jpg
fnew_path=os.path.join(class_path, fname + '.' + 'jpg')
shutil.copy(f_path,fnew_path )
os.remove(f_path)
else:
try:
img=cv2.imread(f_path)
shape=img.shape
if convert_ext !=None:
fnew_path=os.path.join(class_path, fname + '.' + convert_ext)
cv2.imwrite(fnew_path,img)
os.remove (f_path)
class_good_count +=1
except:
if delete:
os.remove(f_path)
class_removed_count +=1
else:
bad_file_list.append(f_path)
print('{0:^20s}{1}{2:^17s}{1}{3:^14s}{1}{4:^15s}'.format(klass,' ', str(class_file_count),str(class_good_count), str(class_removed_count)) )
processed_count=processed_count + class_file_count
good_count=good_count + class_good_count
removed_count=removed_count+ class_removed_count
print('processed ', processed_count, ' files ', good_count, 'files were verified ', removed_count, ' files were removed')
return bad_file_list
以下是使用示例
source_dir=r'c:\temp\people\storage'
good_ext_list=['jpg', 'jpeg', 'bmp', 'tiff', 'png']
new_ext='bmp'
bad_file_list=check_file_extension (source_dir, good_ext_list, delete=False,convert_ext=new_ext )
print (bad_file_list)
下面是典型的输出
Class Directory Files Processed Files Verified Files Removed
savory 20 20 0
unsavory 21 20 0
processed 41 files 40 files were verified 0 files were removed
['c:\\temp\\people\\storage\\unsavory\\040.xyz']