我正在尝试使用 Python 在 Colab 中运行图像平铺脚本，当我尝试重命名和保存文件时，Pillow 抛出错误
这是我的脚本
import pandas as pd
import numpy as np
from PIL import Image
from shapely.geometry import Polygon, Point
from matplotlib import pyplot as plt
import glob
# get all image names
imnames_train = glob.glob('/content/content/drive/My Drive/yolor/training_data/train/*.jpg')
imnames_val = glob.glob('/content/content/drive/My Drive/yolor/training_data/val/*.jpg')
# specify path for a new tiled dataset
newpath_train = '/content/content/drive/My Drive/yolor/sampletiled/train/'
falsepath_train = '/content/content/drive/My Drive/yolor/sampletiled/false_train/'
newpath_val = '/content/content/drive/My Drive/yolor/sampletiled/val/'
falsepath_val = '/content/content/drive/My Drive/yolor/sampletiled/false_val/'
# specify slice width=height
slice_size = 416
# tile all images in a loop
for imname_train in imnames_train:
im = Image.open(imname_train)
imr = np.array(im, dtype=np.uint8)
height = imr.shape[0]
width = imr.shape[1]
labname = imname_train.replace('.jpg', '.txt')
labels = pd.read_csv(labname, sep=' ', names=['class', 'x1', 'y1', 'w', 'h'])
# we need to rescale coordinates from 0-1 to real image height and width
labels[['x1', 'w']] = labels[['x1', 'w']] * width
labels[['y1', 'h']] = labels[['y1', 'h']] * height
boxes = []
# convert bounding boxes to shapely polygons. We need to invert Y and find polygon vertices from center points
for row in labels.iterrows():
x1 = row[1]['x1'] - row[1]['w']/2
y1 = (height - row[1]['y1']) - row[1]['h']/2
x2 = row[1]['x1'] + row[1]['w']/2
y2 = (height - row[1]['y1']) + row[1]['h']/2
boxes.append((int(row[1]['class']), Polygon([(x1, y1), (x2, y1), (x2, y2), (x1, y2)])))
counter = 0
print('Image:', imname_train)
# create tiles and find intersection with bounding boxes for each tile
for i in range((height // slice_size)):
for j in range((width // slice_size)):
x1 = j*slice_size
y1 = height - (i*slice_size)
x2 = ((j+1)*slice_size) - 1
y2 = (height - (i+1)*slice_size) + 1
pol = Polygon([(x1, y1), (x2, y1), (x2, y2), (x1, y2)])
imsaved = False
slice_labels = []
for box in boxes:
if pol.intersects(box[1]):
inter = pol.intersection(box[1])
if not imsaved:
sliced = imr[i*slice_size:(i+1)*slice_size, j*slice_size:(j+1)*slice_size]
sliced_im = Image.fromarray(sliced)
filename = imname_train.split('/')[-1]
slice_path = newpath_train + filename.replace('.jpg', f'_{i}_{j}.jpg')
slice_labels_path = newpath_train + filename.replace('.jpg', f'_{i}_{j}.txt')
print(slice_path)
sliced_im.save(slice_path)
imsaved = True
# get the smallest polygon (with sides parallel to the coordinate axes) that contains the intersection
new_box = inter.envelope
# get central point for the new bounding box
centre = new_box.centroid
# get coordinates of polygon vertices
x, y = new_box.exterior.coords.xy
# get bounding box width and height normalized to slice size
new_width = (max(x) - min(x)) / slice_size
new_height = (max(y) - min(y)) / slice_size
# we have to normalize central x and invert y for yolo format
new_x = (centre.coords.xy[0][0] - x1) / slice_size
new_y = (y1 - centre.coords.xy[1][0]) / slice_size
counter += 1
slice_labels.append([box[0], new_x, new_y, new_width, new_height])
# save txt with labels for the current tile
if len(slice_labels) > 0:
slice_df = pd.DataFrame(slice_labels, columns=['class', 'x1', 'y1', 'w', 'h'])
print(slice_df)
slice_df.to_csv(slice_labels_path, sep=' ', index=False, header=False, float_format='%.6f')
# if there are no bounding boxes intersect current tile, save this tile to a separate folder
if not imsaved:
sliced = imr[i*slice_size:(i+1)*slice_size, j*slice_size:(j+1)*slice_size]
sliced_im = Image.fromarray(sliced)
filename = imname_train.split('/')[2]
slice_path = falsepath_train + filename.replace('.jpg', f'_{i}_{j}.jpg')
sliced_im.save(slice_path)
print('Slice without boxes saved')
imsaved = True
这是我在 colab 控制台中遇到的错误
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
/usr/local/lib/python3.7/dist-packages/PIL/Image.py in save(self, fp, format, **params)
2113 try:
-> 2114 format = EXTENSION[ext]
2115 except KeyError:
KeyError: ''
During handling of the above exception, another exception occurred:
ValueError Traceback (most recent call last)
1 frames
/usr/local/lib/python3.7/dist-packages/PIL/Image.py in save(self, fp, format, **params)
2114 format = EXTENSION[ext]
2115 except KeyError:
-> 2116 raise ValueError("unknown file extension: {}".format(ext))
2117
2118 if format.upper() not in SAVE:
ValueError: unknown file extension:
在脚本底部的这一行抛出错误
sliced_im.save(slice_path)
我尝试将线路更改为
sliced_im.save(slice_path,format='JPG')
这只是给了我这个错误：
KeyError Traceback (most recent call last)
<ipython-input-65-93619c93028b> in <module>()
100 slice_path = falsepath_train + filename.replace('.jpg', f'_{i}_{j}.jpg')
101
--> 102 sliced_im.save(slice_path,format = '.jpg')
103 print('Slice without boxes saved')
104 imsaved = True
/usr/local/lib/python3.7/dist-packages/PIL/Image.py in save(self, fp, format, **params)
2121 save_handler = SAVE_ALL[format.upper()]
2122 else:
-> 2123 save_handler = SAVE[format.upper()]
2124
2125 if open_fp:
KeyError: '.JPG'
有谁知道这是什么原因造成的吗？
使用 PIL 时不要使用 jpg 格式尝试 png
我实际上点击了这个，因为我试图保存文件的目录不存在，并且 PILLOW 没有检查它，所以没有返回可读的错误消息。