python图像处理库Pillow基本使用方法

安装pillow

pillow的文档页面，documentation of Pillow

生成一个有单一颜色的图像

from PIL import Image, ImageDraw
img = Image.new(mode, size, color)
img.save(filename)

There are various values for mode listed in the documentation of Pillow. For example RGB and RGBA can be modes. The size is a tuple in the form of (width, height) in pixels. The color can be a word such as 'red', or a triplet for RGB colors of 3 values between 0-255.

例子

from PIL import Image

img = Image.new('RGB', (60, 30), color = 'red')
img.save('pil_red.png')

使用RGB三个数值创建颜色

from PIL import Image

img = Image.new('RGB', (60, 30), color = (73, 109, 137))
img.save('pil_color.png')

在图像上写字

from PIL import Image, ImageDraw

img = Image.new('RGB', (100, 30), color = (73, 109, 137))

d = ImageDraw.Draw(img)
d.text((10,10), "Hello World", fill=(255,255,0))

img.save('pil_text.png')

换不同的字体

There are a number of ways to select the font used for writing on the image. We need to import and use the ImageFont to load a TrueType font. Mac OSX supplies a bunch of fonts that are located in the /Library/Fonts/. On other platforms you'll need to locate the files yourself and then pass the full path to the function. Alternatively you could include the font-file in your application and then you can know where is the font-file relative to your code.

In this example we load the font using the truetype method of the ImageFont passing to it the path to the fonts and the size of the fonts to be loaded.

from PIL import Image, ImageDraw, ImageFont

img = Image.new('RGB', (100, 30), color = (73, 109, 137))

fnt = ImageFont.truetype('/Library/Fonts/Arial.ttf', 15)
d = ImageDraw.Draw(img)
d.text((10,10), "Hello world", font=fnt, fill=(255, 255, 0))

img.save('pil_text_font.png')