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# python import
import logging, os, struct, StringIO
# atoideweb import
from atoideweb.tools import registry
def compute_width_height(width, height, max_width, max_height, use_max=False):
# compute ratio
_ratio_scr = max_width / float(max_height)
_ratio_img = width / float(height)
# ..
if width > max_width\
or height > max_height:
if _ratio_img > _ratio_scr:
width = max_width
height = int(max_width / _ratio_img)
elif _ratio_img < _ratio_scr:
width = int(max_height * _ratio_img)
height = max_height
else:
width = max_width
height = max_height
# ..
return width, height
# ..
elif use_max is True:
return max_width, max_height
# ..
else:
return width, height
def get_image_info(path):
"""Tricky method found on Internet that returns the image info from a given
raw image data.
"""
# little check
_info = registry.InfoRegistry().get_info(path)
# already exist
if _info is not None:
return _info
elif os.path.exists(path):
pass
else:
return None, 0, 0
# read file
_f = open(path)
_data = _f.read()
_f.close()
#
size = len(_data)
height = 0
width = 0
content_type = None
# handle GIFs
if (size >= 10) and _data[:6] in ('GIF87a', 'GIF89a'):
# Check to see if content_type is correct
content_type = 'image/gif'
w, h = struct.unpack("<HH", _data[6:10])
width = int(w)
height = int(h)
# See PNG 2. Edition spec (http://www.w3.org/TR/PNG/)
# Bytes 0-7 are below, 4-byte chunk length, then 'IHDR'
# and finally the 4-byte width, height
elif ((size >= 24) and _data.startswith('\211PNG\r\n\032\n')
and (_data[12:16] == 'IHDR')):
content_type = 'image/png'
w, h = struct.unpack(">LL", _data[16:24])
width = int(w)
height = int(h)
# Maybe this is for an older PNG version.
elif (size >= 16) and _data.startswith('\211PNG\r\n\032\n'):
# Check to see if we have the right content type
content_type = 'image/png'
w, h = struct.unpack(">LL", _data[8:16])
width = int(w)
height = int(h)
# handle JPEGs
elif (size >= 2) and _data.startswith('\377\330'):
content_type = 'image/jpeg'
jpeg = StringIO.StringIO(_data)
jpeg.read(2)
b = jpeg.read(1)
try:
while (b and ord(b) != 0xDA):
while (ord(b) != 0xFF): b = jpeg.read(1)
while (ord(b) == 0xFF): b = jpeg.read(1)
if (ord(b) >= 0xC0 and ord(b) <= 0xC3):
jpeg.read(3)
h, w = struct.unpack(">HH", jpeg.read(4))
break
else:
jpeg.read(int(struct.unpack(">H", jpeg.read(2))[0])-2)
b = jpeg.read(1)
width = int(w)
height = int(h)
except struct.error:
pass
except ValueError:
pass
# udpate registry
registry.InfoRegistry().set_info(path, (content_type, width, height))
# ..
return content_type, width, height
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