mangle/image.py

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Python
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2011-08-28 14:57:22 +00:00
# Copyright (C) 2010 Alex Yatskov
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
from PIL import Image, ImageDraw
class ImageFlags:
Orient = 1 << 0
Resize = 1 << 1
Frame = 1 << 2
Quantize = 1 << 3
class KindleData:
Palette4 = [
0x00, 0x00, 0x00,
0x55, 0x55, 0x55,
0xaa, 0xaa, 0xaa,
0xff, 0xff, 0xff
]
Palette15 = [
0x00, 0x00, 0x00,
0x11, 0x11, 0x11,
0x22, 0x22, 0x22,
0x33, 0x33, 0x33,
0x44, 0x44, 0x44,
0x55, 0x55, 0x55,
0x66, 0x66, 0x66,
0x77, 0x77, 0x77,
0x88, 0x88, 0x88,
0x99, 0x99, 0x99,
0xaa, 0xaa, 0xaa,
0xbb, 0xbb, 0xbb,
0xcc, 0xcc, 0xcc,
0xdd, 0xdd, 0xdd,
0xff, 0xff, 0xff,
]
Profiles = {
'Kindle 1': ((600, 800), Palette4),
'Kindle 2': ((600, 800), Palette15),
'Kindle 3': ((600, 800), Palette15),
'Kindle DX': ((824, 1200), Palette15),
'Kindle DXG': ((824, 1200), Palette15)
}
def quantizeImage(image, palette):
colors = len(palette) / 3
if colors < 256:
palette = palette + palette[:3] * (256 - colors)
palImg = Image.new('P', (1, 1))
palImg.putpalette(palette)
return image.quantize(palette=palImg)
def resizeImage(image, size):
widthDev, heightDev = size
widthImg, heightImg = image.size
if widthImg <= widthDev and heightImg <= heightDev:
return image
ratioImg = float(widthImg) / float(heightImg)
ratioWidth = float(widthImg) / float(widthDev)
ratioHeight = float(heightImg) / float(heightDev)
if ratioWidth > ratioHeight:
widthImg = widthDev
heightImg = int(widthDev / ratioImg)
elif ratioWidth < ratioHeight:
heightImg = heightDev
widthImg = int(heightDev * ratioImg)
else:
widthImg, heightImg = size
return image.resize((widthImg, heightImg), Image.ANTIALIAS)
def formatImage(image):
if image.mode == 'RGB':
return image
return image.convert('RGB')
def orientImage(image, size):
widthDev, heightDev = size
widthImg, heightImg = image.size
if (widthImg > heightImg) != (widthDev > heightDev):
return image.rotate(90, Image.BICUBIC, True)
return image
def frameImage(image, foreground, background, size):
widthDev, heightDev = size
widthImg, heightImg = image.size
pastePt = (
max(0, (widthDev - widthImg) / 2),
max(0, (heightDev - heightImg) / 2)
)
corner1 = (
pastePt[0] - 1,
pastePt[1] - 1
)
corner2 = (
pastePt[0] + widthImg + 1,
pastePt[1] + heightImg + 1
)
imageBg = Image.new(image.mode, size, background)
imageBg.paste(image, pastePt)
draw = ImageDraw.Draw(imageBg)
draw.rectangle([corner1, corner2], outline=foreground)
return imageBg
def convertImage(source, target, device, flags):
try:
size, palette = KindleData.Profiles[device]
except KeyError:
raise RuntimeError('Unexpected output device %s' % device)
try:
image = Image.open(source)
except IOError:
raise RuntimeError('Cannot read image file %s' % source)
image = formatImage(image)
if flags & ImageFlags.Orient:
image = orientImage(image, size)
if flags & ImageFlags.Resize:
image = resizeImage(image, size)
if flags & ImageFlags.Frame:
image = frameImage(image, tuple(palette[:3]), tuple(palette[-3:]), size)
if flags & ImageFlags.Quantize:
image = quantizeImage(image, palette)
try:
image.save(target)
except IOError:
raise RuntimeError('Cannot write image file %s' % target)