annotate core/image.py @ 631:f36d1a168be7
For issue 27, disable login dialog button during POST.
This seems to prevent multiple logins most of the time. You can
still bang on the enter key and sometimes get more through.
| author |
Brian Neal <bgneal@gmail.com> |
| date |
Wed, 14 Nov 2012 20:57:05 -0600 |
| parents |
ee87ea74d46b |
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234726f5a47a |
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bgneal@265
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1 """
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2 This file contains common utility functions for manipulating images for
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3 the rest of the applications in the project.
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4 """
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5 from PIL import ImageFile
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6 from PIL import Image
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7
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8
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9 def parse_image(file):
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10 """
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11 Returns a PIL Image from the supplied Django file object.
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12 Throws IOError if the file does not parse as an image file or some other
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13 I/O error occurred.
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14
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15 """
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16 parser = ImageFile.Parser()
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17 for chunk in file.chunks():
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18 parser.feed(chunk)
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19 image = parser.close()
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20 return image
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21
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22
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23 def downscale_image_square(image, size):
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24 """
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25 Scale an image to the square dimensions given by size (in pixels).
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26 The new image is returned.
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27 If the image is already smaller than (size, size) then no scaling
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28 is performed and the image is returned unchanged.
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29
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30 """
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31 # don't upscale
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32 if (size, size) >= image.size:
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33 return image
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34
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35 (w, h) = image.size
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36 if w > h:
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37 diff = (w - h) / 2
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38 image = image.crop((diff, 0, w - diff, h))
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39 elif h > w:
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40 diff = (h - w) / 2
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41 image = image.crop((0, diff, w, h - diff))
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42 image = image.resize((size, size), Image.ANTIALIAS)
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43 return image
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