Convert uint8list image to a supported Image file(jpg or etc.)

Question

In android 10 and 11 (SDK number 29 and 30) music covers (artworks) formats aren't the same as previous versions, in fact, they aren't readable as a supported image file such as jpg or png, they are uint8lists and only Image.memory widget accepts and shows them.

Now, my problem is I don't wanna read them as a memory image, I need files such as jpg or etc.

Searched a lot! Read a lot and found only 1, not working solution! And that was writing unit8list as bytes in a file which it's path is ended with ".jpg". As I said it's not working.

Anyone can help?

Thanks in advance, <3.

final io.File image = File('directory/image.jpg').create();
image.writeAsBytesSync(uint8list);

uint8list sample:[255, 216, 255, 224, 0, 16, 74, 70, 73, 70, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 255, 226, 2, 40, 73, 67, 67, 95, 80, 82 ,...]

length: thousands

*"they are uint8lists"* - how you read them? what is their [magic number](https://en.wikipedia.org/wiki/List_of_file_signatures)? — pskink, Dec 28 '20 at 08:05
https://stackoverflow.com/questions/53078493/flutter-qrimage-convert-to-image you can read to result — sanghuynh, Dec 28 '20 at 09:06
@sanghuynh I guess you misunderstood my question! I wanna decode unit8list to jpg not encode it! — M.Taha Basiri, Dec 28 '20 at 09:13
@pskink I don't know a lot about uint8lists and only know that it's an encoding method to compress images as a string data. — M.Taha Basiri, Dec 28 '20 at 09:15
your uint8list is a valid image data, if `Image.memory` can decode it then `Image.file` will do work too if you write your data correctly — pskink, Dec 28 '20 at 12:09
Have you checked [my answer](https://stackoverflow.com/a/63732653/8342742) if this could help? — MαπμQμαπkγVπ.0, Nov 02 '21 at 02:30

score 5 · Accepted Answer · answered Jan 21 '22 at 01:07

5

To write Uint8list as a file, you can use File(String).writeAsBytes(Uint8list);. You can set the path and file extension on the File object and pass the image bytes on writeAsBytes()

Uint8List imageBytes;
File('image.jpg').writeAsBytes(imageBytes);

answered Jan 21 '22 at 01:07

Omatt

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you have any idea, how to write Uint8List as Image data type in flutter – saddam Apr 26 '22 at 05:39
If you're pertaining to the Image widget, you can use [Image.memory(Uint8List)](https://api.flutter.dev/flutter/widgets/Image/Image.memory.html) – Omatt Apr 26 '22 at 09:49
No, I'm not using that in widget.. – saddam Apr 26 '22 at 10:23
How did you know the format of the image, that you want to end the the `path` with like `.jpg` `.png`...etc. – Tayan May 28 '23 at 18:36

Convert uint8list image to a supported Image file(jpg or etc.)

1 Answers1