annotate gpp/core/image.py @ 505:a5d11471d031
Refactor the logic in the rate limiter decorator. Check to see if the request was ajax, as the ajax view always returns 200. Have to decode the JSON response to see if an error occurred or not.
| author |
Brian Neal <bgneal@gmail.com> |
| date |
Sat, 03 Dec 2011 19:13:38 +0000 |
| parents |
1ba2c6bf6eb7 |
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line source |
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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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