python对图片进行裁剪、等比例缩小、添加水印等图像操作代码

"""
皮蛋编程(https://www.pidancode.com)
创建日期：2022/3/28
功能描述：python对图片进行裁剪、等比例缩小、添加水印等图像操作代码
"""

from PIL import Image


# 等比例压缩图片
def resizeImg(**args):
    args_key = {'ori_img': '', 'dst_img': '', 'dst_w': '', 'dst_h': '', 'save_q': 75}
    arg = {}
    for key in args_key:
        if key in args:
            arg[key] = args[key]
    im = Image.open(arg['ori_img'])
    ori_w, ori_h = im.size
    widthRatio = heightRatio = None
    ratio = 1
    if (ori_w and ori_w > arg['dst_w']) or (ori_h and ori_h > arg['dst_h']):
        if arg['dst_w'] and ori_w > arg['dst_w']:
            widthRatio = float(arg['dst_w']) / ori_w  # 正确获取小数的方式
        if arg['dst_h'] and ori_h > arg['dst_h']:
            heightRatio = float(arg['dst_h']) / ori_h
        if widthRatio and heightRatio:
            if widthRatio < heightRatio:
                ratio = widthRatio
            else:
                ratio = heightRatio
        if widthRatio and not heightRatio:
            ratio = widthRatio
        if heightRatio and not widthRatio:
            ratio = heightRatio
        newWidth = int(ori_w * ratio)
        newHeight = int(ori_h * ratio)
    else:
        newWidth = ori_w
        newHeight = ori_h
    im.resize((newWidth, newHeight), Image.ANTIALIAS).save(arg['dst_img'], quality=arg['save_q'])


# 裁剪压缩图片
def clipResizeImg(**args):
    args_key = {'ori_img': '', 'dst_img': '', 'dst_w': '', 'dst_h': '', 'save_q': 75}
    arg = {}
    for key in args_key:
        if key in args:
            arg[key] = args[key]
    im = Image.open(arg['ori_img'])
    ori_w, ori_h = im.size
    dst_scale = float(arg['dst_h']) / arg['dst_w']  # 目标高宽比
    ori_scale = float(ori_h) / ori_w  # 原高宽比
    if ori_scale >= dst_scale:
        # 过高
        width = ori_w
        height = int(width * dst_scale)
        x = 0
        y = (ori_h - height) / 3
    else:
        # 过宽
        height = ori_h
        width = int(height * dst_scale)
        x = (ori_w - width) / 2
        y = 0
    # 裁剪
    box = (x, y, width + x, height + y)
    # 这里的参数可以这么认为：从某图的(x,y)坐标开始截，截到(width+x,height+y)坐标
    # 所包围的图像，crop方法与php中的imagecopy方法大为不一样
    newIm = im.crop(box)
    im = None
    # 压缩
    ratio = float(arg['dst_w']) / width
    newWidth = int(width * ratio)
    newHeight = int(height * ratio)
    newIm.resize((newWidth, newHeight), Image.ANTIALIAS).save(arg['dst_img'], quality=arg['save_q'])


# 水印(这里仅为图片水印)
def waterMark(**args):
    args_key = {'ori_img': '', 'dst_img': '', 'mark_img': '', 'water_opt': ''}
    arg = {}
    for key in args_key:
        if key in args:
            arg[key] = args[key]
    im = Image.open(arg['ori_img'])
    ori_w, ori_h = im.size
    mark_im = Image.open(arg['mark_img'])
    mark_w, mark_h = mark_im.size
    option = {'leftup': (0, 0), 'rightup': (ori_w - mark_w, 0), 'leftlow': (0, ori_h - mark_h),
              'rightlow': (ori_w - mark_w, ori_h - mark_h)
              }
    im.paste(mark_im, option[arg['water_opt']], mark_im.convert('RGBA'))
    im.save(arg['dst_img'])


# 演示代码
# 源图片
ori_img = './test.jpg'
# 水印标
mark_img = './mark.png'
# 水印位置(右下)
water_opt = 'rightlow'
# 目标图片
dst_img = './pidancode.com.jpg'
# 目标图片大小
dst_w = 94
dst_h = 94
# 保存的图片质量
save_q = 35
# 裁剪压缩
# clipResizeImg(ori_img=ori_img,dst_img=dst_img,dst_w=dst_w,dst_h=dst_h,save_q = save_q)
# 等比例压缩
# resizeImg(ori_img=ori_img,dst_img=dst_img,dst_w=dst_w,dst_h=dst_h,save_q=save_q)
# 水印
# waterMark(ori_img=ori_img,dst_img=dst_img,mark_img=mark_img,water_opt=water_opt)