Current File : //usr/lib/calibre/calibre/web/fetch/utils.py
#!/usr/bin/env python3
# License: GPLv3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
from calibre.utils.img import image_from_data, scale_image, image_to_data, blend_on_canvas
def rescale_image(data, scale_news_images, compress_news_images_max_size, compress_news_images_auto_size):
orig_data = data # save it in case compression fails
img = image_from_data(data)
orig_w, orig_h = img.width(), img.height()
if scale_news_images is not None:
wmax, hmax = scale_news_images
if wmax < orig_w or hmax < orig_h:
orig_w, orig_h, data = scale_image(img, wmax, hmax, compression_quality=95)
if compress_news_images_max_size is None:
if compress_news_images_auto_size is None: # not compressing
return data
maxsizeb = (orig_w * orig_h)/compress_news_images_auto_size
else:
maxsizeb = compress_news_images_max_size * 1024
if len(data) <= maxsizeb: # no compression required
return data
scaled_data = data # save it in case compression fails
quality = 90
while len(data) >= maxsizeb and quality >= 5:
data = image_to_data(image_from_data(scaled_data), compression_quality=quality)
quality -= 5
if len(data) >= len(scaled_data): # compression failed
return orig_data if len(orig_data) <= len(scaled_data) else scaled_data
if len(data) >= len(orig_data): # no improvement
return orig_data
return data
def prepare_masthead_image(path_to_image, out_path, mi_width, mi_height):
with lopen(path_to_image, 'rb') as f:
img = image_from_data(f.read())
img = blend_on_canvas(img, mi_width, mi_height)
with lopen(out_path, 'wb') as f:
f.write(image_to_data(img))
if __name__ == '__main__':
import sys
data = sys.stdin.read()
sys.stdout.write(rescale_image(data, (768, 1024), None, 8))
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