pip install pillow
pip install pyqt5

#!-*-coding:utf-8-*-

from PIL import Image

import hashlib, os, sys
from PyQt5.QtGui import QFont, QIcon
from PyQt5.QtWidgets import (QFileDialog, QMessageBox,
  QGridLayout, QLineEdit, QTextEdit, QLabel, QWidget, QToolTip, 
  QPushButton, QApplication, QInputDialog)
from PyQt5.QtCore import QCoreApplication


def makedir(path):
  if not os.path.exists(path):
    os.mkdir(path)


def image_resize(image_path, scale):
  #获得新文件名称
  out_path = os.path.splitext(image_path)[0] + "_after" + os.path.splitext(image_path)[-1]
  with Image.open( image_path ) as im:
    width = int(im.size[0]*scale)
    height = int(im.size[1]*scale)
    #resize 设置新尺寸
    out = im.resize( (width, height) )
    out.save(out_path)

def folder_resize(folder_path, scale):
  dst_files = []
  files = os.listdir( folder_path )
  for file in files:
    ext = os.path.splitext(file)[-1]
    #只支持jpg或png文件
    if ext == ".jpg" or ext == ".png":
      dst_files.append(file)

  #输出路径
  out_folder = os.path.join(folder_path, "after")
  makedir(out_folder)

  for item in dst_files:
    try:
      op = os.path.join( out_folder, item )
      with Image.open( os.path.join(folder_path, item) ) as im:
        width = int(im.size[0]*scale)
        height = int(im.size[1]*scale)
        out = im.resize( (width, height) )
        out.save(op)
    except FileNotFoundError:
      print("file not found " + item)


class MainBody(QWidget):
  def __init__(self):
    super(MainBody, self).__init__()
    self.init()

    self.m_scale = 1.0
    self.m_width = 0
    self.m_height = 0

  def init(self):
    grid = QGridLayout()
    self.setLayout(grid)
    grid.setSpacing(10)

    self.m_tedit = QTextEdit()
    self.m_tedit.setToolTip( u'可以拖拽文件到这里来' )
    grid.addWidget(self.m_tedit, 1, 0, 4, 3)

    self.m_scale_set_btn = QPushButton( u"设置缩放值" )
    self.m_scale_set_btn.clicked.connect( self.set_scale_func )
    grid.addWidget( self.m_scale_set_btn, 1, 3 )
    self.m_scale_label = QLabel( "1.0" )
    grid.addWidget( self.m_scale_label, 2, 3 )

    self.m_height_set_btn = QPushButton( u"设置高度" )
    self.m_height_set_btn.clicked.connect( self.set_height_func )
    grid.addWidget( self.m_height_set_btn, 3, 3 )
    self.m_height_label = QLabel( "0" )
    grid.addWidget( self.m_height_label, 4, 3 )

    self.m_width_set_btn = QPushButton( u"设置宽度" )
    self.m_width_set_btn.clicked.connect( self.set_width_func )
    grid.addWidget( self.m_width_set_btn, 5, 3 )
    self.m_width_label = QLabel( "0" )
    grid.addWidget( self.m_width_label, 6, 3 )

    self.m_file_btn = QPushButton(u'选择文件')
    self.m_file_btn.clicked.connect( self.file_func )

    self.m_folder_btn = QPushButton(u'选择文件夹')
    self.m_folder_btn.clicked.connect( self.folder_func )

    self.m_generate_btn = QPushButton(u'处理')
    self.m_generate_btn.clicked.connect( self.generate_func )

    self.m_clear_btn = QPushButton(u'清空')
    self.m_clear_btn.clicked.connect( self.clear_func )

    grid.addWidget(self.m_file_btn, 5, 0)
    grid.addWidget(self.m_folder_btn, 5, 1)
    grid.addWidget(self.m_generate_btn, 6, 0)
    grid.addWidget(self.m_clear_btn, 6, 1)

    self.setGeometry(300,300,300,200)
    self.setWindowTitle(u"批量图片缩放")
    self.setWindowIcon(QIcon('icon.png'))
    self.show()

  #按照输入的缩放值进行缩放
  def set_scale_func(self):
    text, ok = QInputDialog.getText( self, 'Input Scale', u'输入缩放值' )
    if ok:
      try:
        scale = float( text )
      except ValueError:
        QMessageBox.warning( self, u"设置缩放值", u"输入错误" )
      else:
        self.m_scale = scale
        self.refresh_setting(0)

  #根据高度的缩放比例等比例缩放
  def set_height_func(self):
    text, ok = QInputDialog.getText( self, 'Input Height', u'输入高度' )
    if ok:
      try:
        height = int( text )
      except ValueError:
        QMessageBox.warning( self, u"设置高度", u"输入错误" )
      else:
        self.m_height = height
        self.refresh_setting(2)

  #根据宽度的缩放比例等比例缩放
  def set_width_func(self):
    text, ok = QInputDialog.getText( self, 'Input Width', u'输入宽度' )
    if ok:
      try:
        width = int( text )
      except ValueError:
        QMessageBox.warning( self, u"设置宽度", u"输入错误" )
      else:
        self.m_width = width
        self.refresh_setting(1)

  def file_func(self):
    filename, ok = QFileDialog.getOpenFileName(self, "Open File", "C:/Users/Administrator/Desktop", "JPG (*.jpg);;PNG (*.png)")
    if ok:        
      self.m_tedit.setText( filename )

      size = self.get_image_size( filename )
      s,w,h = self.get_current_setting()
      self.m_width = int(size[0]*s)
      self.m_height = int(size[1]*s)
      self.m_height_label.setText( str( self.m_height ) )
      self.m_width_label.setText( str( self.m_width ) )

  def folder_func(self):
    filename = QFileDialog.getExistingDirectory(self, "Open File", "C:/Users/Administrator/Desktop")
    self.m_tedit.setText( filename )


  def generate_func(self):
    path = self.get_image_path()
    if path == None or path == "":
      QMessageBox.warning( self, u"Error", u"未选择文件" )
      return
    elif os.path.exists(path) == False:
      QMessageBox.warning( self, u"Error", u"文件不存在" )
      return

    if os.path.isdir(path):
      folder_resize( path, self.m_scale )
    elif os.path.isfile(path):
      image_resize( path, self.m_scale )


  def clear_func(self):
    self.m_tedit.clear()
    self.m_width = 0
    self.m_height = 0
    self.m_width_label.setText("0")
    self.m_height_label.setText("0")

  def get_image_size(self, image_path):
    with Image.open(image_path) as im:
      return im.size

  def get_image_path(self):
    path = self.m_tedit.toPlainText()
    if path.startswith( 'file:///' ):
      path = path[8:]
    return path

  def get_current_setting(self):
    return self.m_scale, self.m_width, self.m_height

  def refresh_setting(self, kind):
    s, w, h = self.get_current_setting()
    p = self.get_image_path()
    if kind == 0:
      if p == None or p == "" or os.path.exists(p) == False or os.path.isdir(p) == True:
        w = 0
        h = 0
      else:
        size = self.get_image_size(p)
        w = size[0]*s
        h = size[1]*s

    elif kind == 1:
      if p == None or p == "" or os.path.exists(p) == False:
        QMessageBox.warning( self, u"Warning", u"请先选择文件" )
        return
      elif os.path.isdir(p) == True:
        QMessageBox.warning( self, u"Warning", u"文件夹不能设置宽度" )
        return

      size = self.get_image_size(p)
      w = int(w)
      s = w*1.0/size[0]
      h = int((w/size[0])*size[1])

    elif kind == 2:
      if p == None or p == "" or os.path.exists(p) == False:
        QMessageBox.warning( self, u"Warning", u"请先选择文件" )        
        return
      elif os.path.isdir(p) == True:
        QMessageBox.warning( self, u"Warning", u"文件夹不能设置高度" )
        return

      size = self.get_image_size(p)
      h = int(h)
      s = h*1.0/size[1]
      w = int((h/size[1])*size[0])

    self.m_width = int(w)
    self.m_height = int(h)
    self.m_scale = float(s)
    self.m_width_label.setText(str(self.m_width))
    self.m_height_label.setText(str(self.m_height))
    self.m_scale_label.setText(str(self.m_scale))



if __name__ == "__main__":
  app = QApplication(sys.argv)
  mb = MainBody()
  sys.exit( app.exec_() )