在python（PIL）中，将一个图像集中在另一个图像的顶部，然后将一个图像隐藏在另一个图像中

这项任务是使两个函数，一个是将灰度图像嵌入到RGB函数中。第二个则显示隐藏的“水印”。我已经完成了任务（代码必须通过15个测试，我全部通过了：D），但是如果可能的话，我想整理我的代码。有人告诉我，我本可以用裁剪函数将水印放在照片顶部的中心位置（我不知道怎么做），而不是用数学逻辑

from PIL import Image
#function for embedding the watermark
def add_watermark(clean_file, watermark_file):

#if the files are not compatible
#or doesn't exist end the function
try:
    clean_photo = Image.open(clean_file)
    watermark_photo = Image.open(watermark_file)
except:
    return False

#the images pixels tuple values are attained
clean_photo_size = clean_photo.size
watermark_photo_size = watermark_photo.size

# .load  was used to return a pixel access object
# that can be used to read and modify pixels
#for both images 
photo_array = clean_photo.load()
watermark_array = watermark_photo.load()

#centring the watermarked image on the photo
start_x_coord=int((clean_photo_size[0]-watermark_photo_size[0])/2)
start_y_coord=int((clean_photo_size[1]-watermark_photo_size[1])/2)

#for the pixels that share the same position as the pixels in the
#watermark, manipulate their RGB tuple value to include the watermarks
#greyscale value as part of the original RGB tuple
for line in range(watermark_photo_size[0]):
    for rank in range(watermark_photo_size[1]):
         photo_array [(start_x_coord+line),\
                (start_y_coord+rank)]\
                =(int(((photo_array [(start_x_coord+line),\
                                     (start_y_coord+rank)][0]/10)*10)\
                      +((watermark_array[line,rank]/100)%10)),\
                  int(((photo_array [(start_x_coord+line),\
                                     (start_y_coord+rank)]\
                        [1]/10)*10)+((watermark_array[line,rank]/10)%10)),\
                  int(((photo_array [(start_x_coord+line),\
                                     (start_y_coord+rank)][2]/10)*10)\
                      +(watermark_array[line,rank]%10)))

#create a new file name with _X at the end 
new_File_Name = clean_file[:-4]+"_X"+clean_file[-4:]

#create a new file
clean_photo.save(new_File_Name)

#return true for the test
return True

---

我试图更正这篇文章的拼写和语法，但我已经醒了20个小时了，因此如果我遗漏了任何内容，我向您道歉。

以下是如何将图像水印置于另一幅图像之上的方法：

注意：Image和ImageEnhanced要求将PIL系统库安装到Python运行时

import os 
from os.path import join, exists
import shutil
import Image

class BatchWatermark:

    def __init__(self):
        self.data = []


    def process(self, infolder, outfolder, watermarkImage):
        if not exists(infolder):
            print("Input folder '" + infolder + "' does not exist")
            raise Exception("Input folder '" + infolder + "' does not exist")
        #if exists(outfolder):
        #    shutil.rmtree(outfolder)

        watermark = Image.open(watermarkImage)
        for root, dirs, files in os.walk(infolder):
            for name in files:    
                try:
                    im = Image.open(join(root, name))
                    if im.mode != 'RGBA':
                        im = im.convert('RGBA')
                        layer = Image.new('RGBA', im.size, (0, 0, 0, 0))

                        wm_x, wm_y = watermark.size[0], watermark.size[1]
                        x = (im.size[0] - wm_x)/2
                        y = (im.size[1] - wm_y)/2
                        position = (x, y)
                        layer.paste(watermark, position)
                        if not exists(outfolder):
                            os.makedirs(outfolder)
                        Image.composite(layer, im, layer).save(join(outfolder, name))
                        print "Watermark added to image file '" + outfolder + "/" + name + "'";
                except Exception, (msg):
                    print msg