Method for modifying picture pixel value of Python

When doing the semantic segmentation project, the annotated picture is not standard, and the type is RGBA, and it is the category represented by part of A, so it is necessary to convert the picture into RGB picture

# -*- coding:utf8 -*-
import os
 
from PIL import Image
im = Image.open('123.png')# Open picture 
pix = im.load()# Import Pixel 
width = im.size[0]# Get Width 
height = im.size[1]# Get length 
 
for x in range(width):
  for y in range(height):
    r,g,b,a = im.getpixel((x,y))	
    rgba=(r,g,b,a)
    if(a==0):
      im.putpixel((x,y),(0,0,0,0))
    if(a==255):
      im.putpixel((x,y),(255,255,255,255))
 
im = im.convert('RGB')
im.save('456.png')

Batch processing method

# -*- coding:utf8 -*-
import os
from PIL import Image
 
path = 'SegmentationClass(RGBA)/'
savedpath = 'SegmentationClass/'
filelist = os.listdir(path)
for item in filelist:
  im = Image.open( path + item )# Open picture 
  width = im.size[0]# Get Width 
  height = im.size[1]# Get length 
 
  for x in range(width):
    for y in range(height):
      r,g,b,a = im.getpixel((x,y))	
      if(a==0):
        im.putpixel((x,y),(0,0,0,0))
      if(a==255):
        im.putpixel((x,y),(255,255,255,255))
  im = im.convert('RGB')
  im.save(savedpath + item)
  print('item of %s is saved '%(item))