数据预处理的代码是什么啊？

p=0 
tf = []
for files in os.walk('data/inage', topdown=False):
f= files
for item in tqdm(f[2]);
label = cv2.imread(data/label/0’ format(item), cv2 IMREAD GRAYSCALE)
index0=0 
index1=0 
index2=0 
index3=0
[rows, cols] = 1abel.shape
# print(rows, cols) 
for i in range(rows):
for j in range(cols);
if (label[i, j] == 0):
index0 = index0 +1 
elif (label[i, j] == 1):
index1 =index1 +1 
elif (label[i, j] == 2):
index2=index2 +1 
else:
index3=index3+1
ImageSize#512*512
if (index0 / ImageSize < percentage and indexl/ ImageSize <percentage and\
index2 / ImageSize < percentage and index3/ImageSize<percentage):
 p=p+1
tf. append(item)