Pythonで画像略処理コード

2014年5月7日

def MakeThumb(path, sizes=(75, 32, 16)):
base, ext = os.path.splitext(path)
try:
im = Image.open(path)
except IOError:
return
mode = im.mode
if mode not in ('L’, 'RGB’):
if mode == 'RGBA’:
# 透明画像処理
alpha = im.split()[3]
bgmask = alpha.point(lambda x: 255-x)
im = im.convert('RGB’)
# paste(color, box, mask)
im.paste((255,255,255), None, bgmask)
else:
im = im.convert('RGB’)
width, height = im.size
if width == height:
region = im
else:
if width > height:
delta = (width – height)/2
box = (delta, 0, delta+height, height)
else:
delta = (height – width)/2
box = (0, delta, width, delta+width)
region = im.crop(box)
for size in sizes:
filename = base + “_" + “%sx%s" % (str(size), str(size)) + “.jpg"
thumb = region.resize((size,size), Image.ANTIALIAS)
thumb.save(filename, quality=100) # ディフォルトJPEGの保存品質75