Cannot save PNG

[sueng66]

Why I could not save Image to file ? is there any dependency ? I am using release 9.1.1, here is my code :
im = Image.frombytes('L',(self.iwidth,self.iheight),bytes(self.ibuff))
im.save('/data/'+self.fname+'.png',format='PNG')
and got error :
KeyError: 'PNG'

[radarhere]

There was a similar error in #5034, where the user couldn't save a PNG, and concluded the problem was that they didn't have zlib enabled.

If you run python3 -m PIL, you should see a bunch of information, including whether or not ZLIB is supported by your installation.

If you would just like to save an image, and don't care about the format, you could try saving a JPEG instead.

[sueng66]

happend same thing with JPEG, even with BMP, and running python3 -m PIL tell
PNG image/png
Extensions: .apng, .png
Features: open, save, save_all

[sueng66]

I tested directly it's ok
>>> from PIL import Image
>>> im = Image.frombytes('L',(2,2),b'\x00\x00\x00\x00')
>>> im.save('tes.png')
it's generate tes.png and readable by other application

[radarhere]

What you mean by 'directly'? Are you running your Python code through a different application when it doesn't work?

[sueng66]

I am running above test code inside python, while the error come from my app, I think it's related with the data, still debugging it

[sueng66]

found the problem, I called from the destructor while the resource already unavailable, the solution is delete the class and then wait for a couple seconds to make sure resource still available