Flutter convert image to binary data

Question

How can i covert Image file to binary data ? I'm using a library call image_picker for pick the image from gallery or camera. And I want to convert the image that I picked to binary data.

File image = await ImagePicker.pickImage(source: ImageSource.gallery)
(image as Image).toByteData // the method toByteData here is not pop up.

Vinoth Vino · Accepted Answer · 2020-04-01T08:53:02.423

7

toByteData() method allows converting the image into a byte array. We need to pass the format in the format argument which specifies the format in which the bytes will be returned. It'll return the future that completes with binary data or error.

final pngByteData = await image.toByteData(format: ImageByteFormat.png);

ImageByteFormat enum contains the following constants.

png
rawRgba
rawUnmodified
values

For more information about ImageByteFormat, please have a look at this documentation.

Update : If you want to convert the image file into bytes. Then use readAsByte() method.

var bytes = await ImagePicker.pickImage(source: ImageSource.gallery).readAsBytes();

For converting image into a file, Check out this answer.

edited Apr 01 '20 at 08:53

answered Apr 01 '20 at 07:54

Vinoth Vino

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1

I tried to used the your method but toByteData didn't pop up. – Chheangly Prum Apr 01 '20 at 08:43
2

Is your image in Image type or File type ? If it's in file type, then use readAsBytes method or it's in image type then use toByteData method. Please check my updated answer. – Vinoth Vino Apr 01 '20 at 08:46
Use readAsBytes() method without type casting to Image. It'll work – Vinoth Vino Apr 01 '20 at 08:47
1

Try this var bytes = await ImagePicker.pickImage(source: ImageSource.gallery).readAsBytes(); – Vinoth Vino Apr 01 '20 at 08:48
Thanks alots I'll check it out. – Chheangly Prum Apr 01 '20 at 08:51

score 2 · Answer 2 · edited Apr 01 '20 at 08:44

2

simply use this method

var bytes = await File('filename').readAsBytes();

edited Apr 01 '20 at 08:44

Vinoth Vino

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answered Apr 01 '20 at 07:58

Muhammad Noman

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score 1 · Answer 3 · answered Apr 01 '20 at 08:03

You might want to consider using the toByteData method. It converts an image object into an array of bytes. It returns a future which returns a binary image data or an error if the encoding fails. Here is the implementation from this website: https://api.flutter.dev/flutter/dart-ui/Image/toByteData.html

Future<ByteData> toByteData({ImageByteFormat format = ImageByteFormat.rawRgba}) {
  return _futurize((_Callback<ByteData> callback) {
    return _toByteData(format.index, (Uint8List encoded) {
      callback(encoded?.buffer?.asByteData());
    });
  });
}

The format argument specifies in which encoding format the bytes will be returned in. Hope this helps!

Flutter convert image to binary data

3 Answers3