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I am learning to use 'pillow 5.0' following book 'Automate the boring stuff with python'

The info about the image object

In [79]: audacious = auda
In [80]: print(audacious.format, audacious.size, audacious.mode)
PNG (1094, 960) RGBA

When I tried to convert filetype, it report error.

In [83]: audacious.save('audacious.jpg')
OSError: cannot write mode RGBA as JPEG

There's no such a n error in book.

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  • 2
    the duped answer is not a 100% dupe, but will help you solve the problem - My answer holds the reason you get this error
    – Patrick Artner
    Commented Jan 14, 2018 at 10:01
  • 1
    I second this. This question refers specifically how to resolve that exception. I ran into this without using PNGs so would not have found it otherwise.
    – Justin Meiners
    Commented Apr 25, 2021 at 2:10

2 Answers 2

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282

JPG does not support transparency - RGBA means Red, Green, Blue, Alpha - Alpha is transparency.

You need to discard the Alpha Channel or save as something that supports transparency - like PNG.

The Image class has a method convert which can be used to convert RGBA to RGB - after that you will be able to save as JPG.

Have a look here: the image class doku

im = Image.open("audacious.png")
rgb_im = im.convert('RGB')
rgb_im.save('audacious.jpg')

Adapted from dm2013's answer to Convert png to jpeg using Pillow

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  • 43
    As @timop suggests in this answer, a more efficient way is to check whether its in RGBA/P format first before converting to RGB: if im.mode in ("RGBA", "P"): im = im.convert("RGB")
    – Prahlad Yeri
    Commented Apr 28, 2020 at 9:49
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    @Prahlad good to do if you do not know you have a RGBA - this question used a RGBA to begin with
    – Patrick Artner
    Commented Apr 28, 2020 at 10:47
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You can use only .png mode for save image in RGBA

im = Image.open("audacious.jpg")
rgb_im = im.convert('RGBA')
rgb_im.save('audacious.png')
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