Python编程：pillow对图像的简单处理

图片属性

from PIL import Image

def show_info():
    im = Image.open("image.jpg")
    print(im.mode)  # RGB
    print(im.format)  # JPEG
    print(im.size)  # (1200, 800)
    print(im.filename)  # image.jpg
    print(im.width)  # 1200
    print(im.height)  # 800

image.jpg

转换图片格式

jpg -> png

def convert_format():
    Image.open("image.jpg").save("image.png")

    im = Image.open("image.png")
    print(im.mode)  # RGB
    print(im.format)  # PNG

创建缩略图

def create_thumbnail():
    im = Image.open("image.jpg")
    im.thumbnail((120, 80))
    im.save("image_thumbnail.jpg", "PNG")

image_thumbnail.jpg

裁剪图片

def crop_iamge():
    im = Image.open("image.jpg")
    box = (206, 180, 994, 648)   # 左上角和右下角坐标，类似qq截图
    region = im.crop(box)
    region.save("image_region.jpg")

    # 处理子图，旋转180度，粘贴回原图
    region = region.transpose(Image.ROTATE_180)
    im.paste(region, box)
    im.save("image_paste.jpg")

image_region.jpg

image_paste.jpg

左右翻转图片

def roll_image():
    im = Image.open("image_region.jpg")
    image = im.copy()
    delta = 2
    width_half = image.width // delta

    box_left = (0, 0, width_half, image.height)
    box_right = (width_half, 0, image.width, image.height)

    part_left = image.crop(box_left)
    part_right = image.crop(box_right)

    image.paste(part_left, box_right)
    image.paste(part_right, box_left)

    image.save("image_roll.jpg")

image_roll.jpg

图片的分离和合并

def split_merge():
    im = Image.open("image_region.jpg")
    r, g, b = im.split()

    print(r, g, b)

    r.save("r.jpg")
    g.save("g.jpg")
    b.save("b.jpg")

    image = Image.merge("RGB", (r, g, b))
    image.save("image_merge.jpg")

r.jpg

g.jpg

b.jpg

image_merge.jpg

改变大小

def resize():
    im = Image.open("image_region.jpg")
    out = im.resize((128, 128))
    out.save("image_resize.jpg")

image_resize.jpg

旋转图片

def rotate():
    im = Image.open("image_region.jpg")
    out = im.rotate(45)
    out.save("image_rotate.jpg")

image_rotate.jpg

转置图片

逆时针

def transpose():
    im = Image.open("image_region.jpg")

    # 左右镜像
    out = im.transpose(Image.FLIP_LEFT_RIGHT)
    out.save("image_flip_left_right.jpg")

    # 上下镜像
    out = im.transpose(Image.FLIP_TOP_BOTTOM)
    out.save("image_flip_top_bottom.jpg")

    # 旋转90度
    out = im.transpose(Image.ROTATE_90)
    out.save("image_rotate_90.jpg")

    # 旋转180度
    out = im.transpose(Image.ROTATE_180)
    out.save("image_rotate_180.jpg")

    # 旋转270度
    out = im.transpose(Image.ROTATE_270)
    out.save("image_rotate_270.jpg")

image_flip_left_right.jpg

image_rotate_90.jpg

转为黑白图片

def convert_l():
    im = Image.open('image_region.jpg').convert('L')
    im.save("image_l.jpg")

image_l.jpg

图像增强

from PIL import ImageFilter

def filter():
    im = Image.open('image_region.jpg')
    im.filter(ImageFilter.DETAIL)
    im.save("image_detail.jpg")

image_detail.jpg

像素点处理

im = Image.open('image_region.jpg')
out = im.point(lambda i: i * 1.2)
out.save("image_point.jpg")

image_region.jpg

参考

1. 1. 
      
2. ​​PIL 中的 Image 模块​​
3. ​​Python图像处理库：Pillow 初级教程​​
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