Python3 使用pli優化圖檔大小，相機或手機拍圖檔根據exif旋轉、糾正方向

首先安裝

pip install pillow           

如果報錯，請根據報錯的資訊去搜尋一下，一般都能得到解決，未找到請更新pip

python -m pip install --upgrade pip           

或者

pip install --upgrade pip           

那麼寫個方法

from PIL import Image,ExifTags

#定義儲存圖檔都路徑
def get_outfile(infile, outfile):
  if outfile:
  return outfile
  dir, suffix = os.path.splitext(infile)
  outfile = '{}-cover{}'.format(dir, suffix)
  return outfile
 
#縮小圖檔大小，保持原始寬高
def compress_image(infile, outfile='', kb=3200, step=5, quality=80):
  o_size = os.path.getsize(infile) / 1024
  if o_size <= kb:
    return False
  outfile = self.get_outfile(infile, outfile)
  while o_size > kb:
    img = Image.open(infile)
    #相機或手機拍攝圖檔需要根據exif旋轉角度
    try:
      for orientation in ExifTags.TAGS.keys():
        if ExifTags.TAGS[orientation] == 'Orientation': break
      exif = dict(img._getexif().items())
      if exif[orientation] == 3:
        img = img.rotate(180, expand=True)
      elif exif[orientation] == 6:
        img = img.rotate(270, expand=True)
      elif exif[orientation] == 8:
        img = img.rotate(90, expand=True)
    except:
      pass
    img.save(outfile, quality=quality)
  if quality - step < 0:
  break
  quality -= step
  o_size = os.path.getsize(outfile) / 1024
  return outfile           

compress_image(infile, outfile='', kb=3200, step=5, quality=80)
infile : 原始圖檔路徑
outfile: 生成圖檔儲存路徑
kb     : 圖檔壓縮上限，機關kb
step   : 每次壓縮品質，
quality: 圖檔品質，jpg特有，最高為100的品質           

使用

small_path = compress_image(image_path)
if not small_path:
small_path = image_path           

在某個項目中用到，就記錄一下吧～特别是碰到圖檔上傳後改變了方向的，特别郁悶，是以找到了解決方案

img = Image.open(infile)
    #相機或手機拍攝圖檔需要根據exif旋轉角度
    try:
      for orientation in ExifTags.TAGS.keys():
        if ExifTags.TAGS[orientation] == 'Orientation': break
      exif = dict(img._getexif().items())
      if exif[orientation] == 3:
        img = img.rotate(180, expand=True)
      elif exif[orientation] == 6:
        img = img.rotate(270, expand=True)
      elif exif[orientation] == 8:
        img = img.rotate(90, expand=True)
    except:
      pass
    img.save(outfile, quality=100)