Convert a UInt8List to Image in flutter/dart-ui
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I have this scenario where I have to get a UInt8List from an image like that:
List stuff = image.toByteData().buffer.asUInt8List()
Do some manipulations and get back to a Image.
I've tried the following:
List stuff = image.toByteData().buffer.asUInt8List()
ui.decodeImageFromList(stuff, (image){
// do stuff with image
});
But I keep getting this Exception:
E/flutter (10201): [ERROR:flutter/lib/ui/painting/codec.cc(97)] Failed decoding image. Data is either invalid, or it is encoded using an unsupported format.
E/flutter (10201): [ERROR:flutter/shell/common/shell.cc(186)] Dart Error: Unhandled exception:
...
Take notice that even without any changes in the List the exception is thrown. How can I make the list have a encodable format?
dart
flutter asked Jan 3 at 21:55
Renan C. AraujoRenan C. Araujo
28518
add a comment |
I have this scenario where I have to get a UInt8List from an image like that:
List stuff = image.toByteData().buffer.asUInt8List()
Do some manipulations and get back to a Image.
I've tried the following:
List stuff = image.toByteData().buffer.asUInt8List()
ui.decodeImageFromList(stuff, (image){
// do stuff with image
});
But I keep getting this Exception:
E/flutter (10201): [ERROR:flutter/lib/ui/painting/codec.cc(97)] Failed decoding image. Data is either invalid, or it is encoded using an unsupported format.
E/flutter (10201): [ERROR:flutter/shell/common/shell.cc(186)] Dart Error: Unhandled exception:
...
Take notice that even without any changes in the List the exception is thrown. How can I make the list have a encodable format?
dart
flutter asked Jan 3 at 21:55
Renan C. AraujoRenan C. Araujo
28518
add a comment |
I have this scenario where I have to get a UInt8List from an image like that:
List stuff = image.toByteData().buffer.asUInt8List()
Do some manipulations and get back to a Image.
I've tried the following:
List stuff = image.toByteData().buffer.asUInt8List()
ui.decodeImageFromList(stuff, (image){
// do stuff with image
});
But I keep getting this Exception:
E/flutter (10201): [ERROR:flutter/lib/ui/painting/codec.cc(97)] Failed decoding image. Data is either invalid, or it is encoded using an unsupported format.
E/flutter (10201): [ERROR:flutter/shell/common/shell.cc(186)] Dart Error: Unhandled exception:
...
Take notice that even without any changes in the List the exception is thrown. How can I make the list have a encodable format?
dart
flutter asked Jan 3 at 21:55
Renan C. AraujoRenan C. Araujo
28518
I have this scenario where I have to get a UInt8List from an image like that:
List stuff = image.toByteData().buffer.asUInt8List()
Do some manipulations and get back to a Image.
I've tried the following:
List stuff = image.toByteData().buffer.asUInt8List()
ui.decodeImageFromList(stuff, (image){
// do stuff with image
});
But I keep getting this Exception:
E/flutter (10201): [ERROR:flutter/lib/ui/painting/codec.cc(97)] Failed decoding image. Data is either invalid, or it is encoded using an unsupported format.
E/flutter (10201): [ERROR:flutter/shell/common/shell.cc(186)] Dart Error: Unhandled exception:
...
Take notice that even without any changes in the List the exception is thrown. How can I make the list have a encodable format?
dart
flutter dart
flutter asked Jan 3 at 21:55
Renan C. AraujoRenan C. Araujo
28518
asked Jan 3 at 21:55
Renan C. AraujoRenan C. Araujo
28518
asked Jan 3 at 21:55
Renan C. AraujoRenan C. Araujo
28518
asked Jan 3 at 21:55
Renan C. AraujoRenan C. Araujo
28518
asked Jan 3 at 21:55
Renan C. AraujoRenan C. Araujo
28518
28518
add a comment |
add a comment |
1 Answer
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ui.Image can turn itself into an RGBA bitmap (or PNG), but cannot convert itself back from a bitmap. (The reason for this is that there isn't any way to tell the image codec things like the color depth, geometry, etc.) The solution is to add a BMP file header onto the front of your bitmap, where you can describe those missing things, then pass that to instantiateImageCodec. See this answer, but note that in that case the bitmap in question had a strange packed color map. In your case of 32 bit RGBA, the header would be even simpler.
answered Jan 3 at 22:42
Richard HeapRichard Heap
8,00121119
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
ui.Image can turn itself into an RGBA bitmap (or PNG), but cannot convert itself back from a bitmap. (The reason for this is that there isn't any way to tell the image codec things like the color depth, geometry, etc.) The solution is to add a BMP file header onto the front of your bitmap, where you can describe those missing things, then pass that to instantiateImageCodec. See this answer, but note that in that case the bitmap in question had a strange packed color map. In your case of 32 bit RGBA, the header would be even simpler.
answered Jan 3 at 22:42
Richard HeapRichard Heap
8,00121119
add a comment |
ui.Image can turn itself into an RGBA bitmap (or PNG), but cannot convert itself back from a bitmap. (The reason for this is that there isn't any way to tell the image codec things like the color depth, geometry, etc.) The solution is to add a BMP file header onto the front of your bitmap, where you can describe those missing things, then pass that to instantiateImageCodec. See this answer, but note that in that case the bitmap in question had a strange packed color map. In your case of 32 bit RGBA, the header would be even simpler.
answered Jan 3 at 22:42
Richard HeapRichard Heap
8,00121119
add a comment |
ui.Image can turn itself into an RGBA bitmap (or PNG), but cannot convert itself back from a bitmap. (The reason for this is that there isn't any way to tell the image codec things like the color depth, geometry, etc.) The solution is to add a BMP file header onto the front of your bitmap, where you can describe those missing things, then pass that to instantiateImageCodec. See this answer, but note that in that case the bitmap in question had a strange packed color map. In your case of 32 bit RGBA, the header would be even simpler.
answered Jan 3 at 22:42
Richard HeapRichard Heap
8,00121119
ui.Image can turn itself into an RGBA bitmap (or PNG), but cannot convert itself back from a bitmap. (The reason for this is that there isn't any way to tell the image codec things like the color depth, geometry, etc.) The solution is to add a BMP file header onto the front of your bitmap, where you can describe those missing things, then pass that to instantiateImageCodec. See this answer, but note that in that case the bitmap in question had a strange packed color map. In your case of 32 bit RGBA, the header would be even simpler.
answered Jan 3 at 22:42
Richard HeapRichard Heap
8,00121119
answered Jan 3 at 22:42
Richard HeapRichard Heap
8,00121119
answered Jan 3 at 22:42
Richard HeapRichard Heap
8,00121119
answered Jan 3 at 22:42
Richard HeapRichard Heap
8,00121119
8,00121119
add a comment |
add a comment |
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