通道分离与滤镜
python
from PIL import Image, ImageFilter
im1 = Image.open("kfc-1.jpg")
im2 = Image.open("kfc-2.jpg").resize(im1.size)
# 通道分离与重组
r1, g1, b1 = im1.split()
r2, g2, b2 = im2.split()
merged = Image.merge("RGB", (r1, g2, b1)) # R 来自 im1,G 来自 im2,B 来自 im1
merged.show()
```
# 应用滤镜
```python
blur = im1.filter(ImageFilter.GaussianBlur(radius=5))
blur.show()
数学合成运算(ImageChops)
python
from PIL import Image, ImageChops
im1 = Image.open("kfc-1.jpg")
im2 = Image.open("kfc-2.jpg").resize(im1.size)
# 加法:加亮叠加区域
ImageChops.add(im1, im2).show()
# 减法:突出差异
ImageChops.subtract(im1, im2).show()
# 取暗 / 取亮
ImageChops.darker(im1, im2).show()
ImageChops.lighter(im1, im2).show()
# 反相
ImageChops.invert(im1).show()
# 差异
ImageChops.difference(im1, im2).show()
色彩与亮度增强
python
from PIL import Image, ImageEnhance
im = Image.open("kfc-1.jpg")
# 色彩增强(彩度)
enhancer = ImageEnhance.Color(im)
enhancer.enhance(2.0).show() # >1 提升彩度,<1 降低彩度
# 亮度增强
enhancer = ImageEnhance.Brightness(im)
enhancer.enhance(1.5).show() # >1 更亮,<1 更暗
# 对比度增强
enhancer = ImageEnhance.Contrast(im)
enhancer.enhance(1.8).show()
绘制基本图形与文本
python
from PIL import Image, ImageDraw, ImageFont
# 新建画布
canvas = Image.new("RGB", (300, 200), color="white")
draw = ImageDraw.Draw(canvas)
# 绘制矩形、椭圆、线条
draw.rectangle((20, 20, 120, 80), outline="red", fill="blue")
draw.ellipse((150, 20, 280, 100), outline="green", fill=None)
draw.line((0, 199, 299, 0), fill="black", width=2)
# 绘制文字
font = ImageFont.truetype("arial.ttf", size=24)
draw.text((30, 120), "Hello, Pillow!", font=font, fill="purple")
canvas.show()
ImageDraw.Draw:所有绘制动作都发生在同一个 canvas 上;
文字需要指定 ImageFont.truetype 字体文件;