def rescale_image(data, maxsizeb=IMAGE_MAX_SIZE, dimen=None):
'''
Convert image setting all transparent pixels to white and changing format
to JPEG. Ensure the resultant image has a byte size less than
maxsizeb.
If dimen is not None, generate a thumbnail of
width=dimen, height=dimen or width, height = dimen (depending on the type
of dimen)
Returns the image as a bytestring
'''
if dimen is not None:
if hasattr(dimen, '__len__'):
width, height = dimen
else:
width = height = dimen
data = thumbnail(data,
width=width,
height=height,
compression_quality=90)[-1]
else:
# Replace transparent pixels with white pixels and convert to JPEG
data = save_cover_data_to(data, 'img.jpg', return_data=True)
if len(data) <= maxsizeb:
return data
orig_data = data
img = Image()
quality = 95
img.load(data)
while len(data) >= maxsizeb and quality >= 10:
quality -= 5
img.set_compression_quality(quality)
data = img.export('jpg')
if len(data) <= maxsizeb:
return data
orig_data = data
scale = 0.9
while len(data) >= maxsizeb and scale >= 0.05:
img = Image()
img.load(orig_data)
w, h = img.size
img.size = (int(scale * w), int(scale * h))
img.set_compression_quality(quality)
data = img.export('jpg')
scale -= 0.05
return data
def rescale_image(data, maxsizeb=IMAGE_MAX_SIZE, dimen=None):
'''
Convert image setting all transparent pixels to white and changing format
to JPEG. Ensure the resultant image has a byte size less than
maxsizeb.
If dimen is not None, generate a thumbnail of
width=dimen, height=dimen or width, height = dimen (depending on the type
of dimen)
Returns the image as a bytestring
'''
if dimen is not None:
if hasattr(dimen, '__len__'):
width, height = dimen
else:
width = height = dimen
data = thumbnail(data, width=width, height=height,
compression_quality=90)[-1]
else:
# Replace transparent pixels with white pixels and convert to JPEG
data = save_cover_data_to(data, 'img.jpg', return_data=True)
if len(data) <= maxsizeb:
return data
orig_data = data
img = Image()
quality = 95
img.load(data)
while len(data) >= maxsizeb and quality >= 10:
quality -= 5
img.set_compression_quality(quality)
data = img.export('jpg')
if len(data) <= maxsizeb:
return data
orig_data = data
scale = 0.9
while len(data) >= maxsizeb and scale >= 0.05:
img = Image()
img.load(orig_data)
w, h = img.size
img.size = (int(scale*w), int(scale*h))
img.set_compression_quality(quality)
data = img.export('jpg')
scale -= 0.05
return data
