Image to RGB matrix in flutter - flutter

Question

I am a beginner in Flutter. I want to choose an image from my local and convert it into an RGB array. Can anybody please provide me with the code to do so correctly?

Answer 1

You can use this package - image
It provides image conversion and manipulation utility functions.
import 'package:image/image.dart' as Imagi;
Here's how to use it to obtain RGB matrix of a file from ImagePicker()-
final image = await ImagePicker().pickImage(source: ImageSource.gallery);
if (image == null) return;
final imageTemp = File(image.path);
controlImage = imageTemp;
Now here's a function for obtaining the RGB matrix -
List<List<int>> imgArray = [];
void readImage() async{
final bytes = await controlImage!.readAsBytes();
final decoder = Imagi.JpegDecoder();
final decodedImg = decoder.decodeImage(bytes);
final decodedBytes = decodedImg!.getBytes(format: Imagi.Format.rgb);
// print(decodedBytes);
print(decodedBytes.length);
// int loopLimit = decodedImg.width;
int loopLimit =1000;
for(int x = 0; x < loopLimit; x++) {
int red = decodedBytes[decodedImg.width*3 + x*3];
int green = decodedBytes[decodedImg.width*3 + x*3 + 1];
int blue = decodedBytes[decodedImg.width*3 + x*3 + 2];
imgArray.add([red, green, blue]);
}
print(imgArray);
}
The array imgArray will contain the RGB matrix