python-pyinsane脚本失败

Question

我需要一些关于python脚本的帮助。该脚本是Python的Py疯狂模块的示例脚本。（疯狂https://github.com/jflesch/pyinsane)我想写我自己的扫描程序脚本，但要做到这一点，我应该理解示例代码或输出错误。

脚本示例。

import sys
``from PIL import Image
try:
   import src.abstract as pyinsane
except ImportError:
   import pyinsane.abstract as pyinsane

def set_scanner_opt(scanner, opt, value):
   print("Setting %s to %s" % (opt, str(value)))
   try:
       scanner.options[opt].value = value
   except (KeyError, pyinsane.SaneException) as exc:
       print("Failed to set %s to %s: %s" % (opt, str(value), str(exc)))

if __name__ == "__main__":
   steps = False
   args = sys.argv[1:]
   if len(args) <= 0 or args[0] == "-h" or args[0] == "--help":
       print("Syntax:")
       print("  %s [-s] <output file (JPG)>" % sys.argv[0])
       print("")
       print("Options:")
       print("  -s : Generate intermediate images (may generate a lot of"
             " images !)")
       sys.exit(1)
   for arg in args[:]:
       if arg == "-s":
           steps = True
           args.remove(arg)
   output_file = args[0]
   print("Output file: %s" % output_file)
   print("Looking for scanners ...")
   devices = pyinsane.get_devices()
   if (len(devices) <= 0):
       print("No scanner detected !")
       sys.exit(1)
   print("Devices detected:")
   print("- " + "n- ".join([str(d) for d in devices]))
   print("")
   device = devices[0]
   print("Will use: %s" % str(device))
   print("")
   source = 'Auto'
   if (device.options['source'].constraint_type
           == pyinsane.SaneConstraintType.STRING_LIST):
       if 'Auto' in device.options['source'].constraint:
           source = 'Auto'
       elif 'FlatBed' in device.options['source'].constraint:
           source = 'FlatBed'
   else:
       print("Warning: Unknown constraint type on the source: %d"
             % device.options['source'].constraint_type)
   set_scanner_opt(device, 'resolution', 300)
   set_scanner_opt(device, 'source', source)
   set_scanner_opt(device, 'mode', 'Color')
   print("")
   print("Scanning ...  ")
   scan_session = device.scan(multiple=False)
   if steps and scan_session.scan.expected_size[1] < 0:
       print("Warning: requested step by step scan images, but"
             " scanner didn't report the expected number of lines"
             " in the final image --> can't do")
       print("Step by step scan images won't be recorded")
       steps = False
   if steps:
       last_line = 0
       expected_size = scan_session.scan.expected_size
       img = Image.new("RGB", expected_size, "#ff00ff")
       sp = output_file.split(".")
       steps_filename = (".".join(sp[:-1]), sp[-1])
   try:
       PROGRESSION_INDICATOR = ['|', '/', '-', '\']
       i = -1
       while True:
           i += 1
           i %= len(PROGRESSION_INDICATOR)
           sys.stdout.write("b%s" % PROGRESSION_INDICATOR[i])
           sys.stdout.flush()
           scan_session.scan.read()
           if steps:
               next_line = scan_session.scan.available_lines[1]
               if (next_line > last_line):
                   subimg = scan_session.scan.get_image(last_line, next_line)
                   img.paste(subimg, (0, last_line))
                   img.save("%s-%05d.%s" % (steps_filename[0], last_line,
                                        steps_filename[1]), "JPEG")
               last_line = next_line
   except EOFError:
       pass
   print("b ")
   print("Writing output file ...")
   img = scan_session.images[0]
   img.save(output_file, "JPEG")
   print("Done")

现在输出：

sudo python /home/pi/Desktop/scantest.py -s 1
Output file: 1
Looking for scanners ...
Devices detected:
- Scanner 'genesys:libusb:001:006' (Canon, LiDE 110, flatbed scanner)
Will use: Scanner 'genesys:libusb:001:006' (Canon, LiDE 110, flatbed scanner)
Setting resolution to 300
Setting source to Auto
Failed to set source to Auto: <class 'pyinsane.rawapi.SaneStatus'> : Data is       invalid (4)
Setting mode to Color
Scanning ...  
|Traceback (most recent call last):
  File "/home/pi/Desktop/scantest.py", line 107, in <module>
    steps_filename[1]), "JPEG")
  File "/usr/local/lib/python2.7/dist-packages/PIL/Image.py", line 1439, in save
    save_handler(self, fp, filename)
  File "/usr/local/lib/python2.7/dist-packages/PIL/PngImagePlugin.py", line 572, in _save
    ImageFile._save(im, _idat(fp, chunk), [("zip", (0,0)+im.size, 0, rawmode)])
  File "/usr/local/lib/python2.7/dist-packages/PIL/ImageFile.py", line 481, in _save
    e = Image._getencoder(im.mode, e, a, im.encoderconfig)
   File "/usr/local/lib/python2.7/dist-packages/PIL/Image.py", line 399, in  _getencoder
    return apply(encoder, (mode,) + args + extra)
 TypeError: an integer is required

请有人解释一下示例代码或帮助我解决输出错误吗？

非常感谢

月桂醇

Answer 1

您的PIL/Pillow库是否使用JPEG支持编译？如果没有，请尝试更换：

img.save("%s-%05d.%s" % (steps_filename[0], last_line,
                                    steps_filename[1]), "JPEG")

通过

img.save("%s-%05d.%s" % (steps_filename[0], last_line,
                                    steps_filename[1]), "PNG")

和

img.save(output_file, "JPEG")

通过

img.save(output_file, "PNG")