用PIL库进行图像处理

一、如果系统里没有安装PIL库的，请先到命令提示符输入“pip install pillow”进行安装

二、之后就可以参考以下的代码

 from PIL import Image
 from pylab import *

 # 添加中文字体支持
 from matplotlib.font_manager import FontProperties
 font = FontProperties(fname=r"c:\windows\fonts\SimSun.ttc", size=14)
 figure()

 pil_im = Image.open('E:\python\Python Computer Vision\Image data\empire.jpg')
 gray()
 subplot(121)
 title(u'原图',fontproperties=font)
 axis('off')
 imshow(pil_im)

 pil_im = Image.open('E:\python\Python Computer Vision\Image data\empire.jpg').convert('L')
 subplot(122)
 title(u'灰度图',fontproperties=font)
 axis('off')
 imshow(pil_im)

 show()

三，可以观看效果

四、其还可以进行旋转等操作

 from PIL import Image
 from pylab import *

 # 添加中文字体支持
 from matplotlib.font_manager import FontProperties

 font = FontProperties(fname=r"c:\windows\fonts\SimSun.ttc", size=14)
 figure()

 # 显示原图
 pil_im = Image.open('E:/python/Python Computer Vision/Image data/empire.jpg')
 print(pil_im.mode, pil_im.size, pil_im.format)
 subplot(231)
 title(u'原图', fontproperties=font)
 axis('off')
 imshow(pil_im)

 # 显示灰度图
 pil_im = Image.open('E:/python/Python Computer Vision/Image data/empire.jpg').convert('L')
 gray()
 subplot(232)
 title(u'灰度图', fontproperties=font)
 axis('off')
 imshow(pil_im)

 # 复制并粘贴区域
 pil_im = Image.open('E:/python/Python Computer Vision/Image data/empire.jpg')
 box = (100, 100, 400, 400)
 region = pil_im.crop(box)
 region = region.transpose(Image.ROTATE_180)
 pil_im.paste(region, box)
 subplot(233)
 title(u'复制粘贴区域', fontproperties=font)
 axis('off')
 imshow(pil_im)

 # 缩略图
 pil_im = Image.open('E:/python/Python Computer Vision/Image data/empire.jpg')
 size = 128, 128
 pil_im.thumbnail(size)
 print(pil_im.size)
 subplot(234)
 title(u'缩略图', fontproperties=font)
 axis('off')
 imshow(pil_im)
 pil_im.save('E:/python/Python Computer Vision/Image data/empire thumbnail.jpg')# 保存缩略图

 #调整图像尺寸
 pil_im=Image.open('E:/python/Python Computer Vision/Image data/empire thumbnail.jpg')
 pil_im=pil_im.resize(size)
 print(pil_im.size)
 subplot(235)
 title(u'调整尺寸后的图像',fontproperties=font)
 axis('off')
 imshow(pil_im)

 #旋转图像45°
 pil_im=Image.open('E:/python/Python Computer Vision/Image data/empire thumbnail.jpg')
 pil_im=pil_im.rotate(45)
 subplot(236)
 title(u'旋转45°后的图像',fontproperties=font)
 axis('off')
 imshow(pil_im)

 show()

查看效果：