in InputImage.fromBytes, InputImageData is required while InputImage.fromFile does not require it

[anil-shrestha]

In InputImage.fromBytes, InputImageData is required while InputImage.fromFile does not require it

for that to work I am writing the bytes to file and then loading InputImage.

Uint8List? imageString = base64Decode(<base64 string>); final dir = (await getTemporaryDirectory()).path; final imageFile = File('$dir/a.png')..writeAsBytesSync(imageString!); final image = InputImage.fromFile(imageFile);

How can I achieve without saving bytes to file.

Thank you.

[fbernaly]

How did you get the bytes in the first instance? I mean the first line: base64Decode(<base64 string>)

[anil-shrestha]

How did you get the bytes in the first instance? I mean the first line: base64Decode(<base64 string>)

I am getting base64 string from api response.

[fbernaly]

Could you be more specific?

How you reading the image? Could you share the code how you are doing that? What plugin you are using to read the image? Image_picker? Camera?

[anil-shrestha]

Could you be more specific?

How you reading the image? Could you share the code how you are doing that? What plugin you are using to read the image? Image_picker? Camera?

final response = await http.get(<uri>);    
final jsonObj = jsonDecode(response.body);
final base64String = jsonObj['imageString'];

Uint8List imageString = base64Decode(base64String);
final dir = (await getTemporaryDirectory()).path;
final imageFile = File('$dir/a.png')..writeAsBytesSync(imageString);
final image = InputImage.fromFile(imageFile);

[fbernaly]

Oh, I see, you are downloading the image from the cloud. In that case I think what you are doing is correct: you need to create a File from the url. You wont be able to use the other constructor: InputImage.fromBytes because you do not have the InputImageData which comes from camera device that is taking the photo. I was looking in stackoverflow if there is an easier way to get a File from Url, but I think you approach is correct: https://stackoverflow.com/questions/59546381/how-to-get-image-from-url-to-a-file-in-flutter I dont think there is much left to do, therefore closing this ticket.

[badpaybad]

I have the same question too. How to convert jpeg Uint8List into InputImage. Jpeg in Uint8List can come from any source file, api ... Cause I use google ML kits, eg: ` import 'package:google_mlkit_pose_detection/google_mlkit_pose_detection.dart';

final PoseDetector _poseDetector = PoseDetector( options: PoseDetectorOptions(mode: PoseDetectionMode.single)); var poses = await _poseDetector.processImage(inputImage); `

[badpaybad]

I found this one android only :

` import 'package:image/image.dart' as AndroidImage; import 'package:camera/camera.dart'; import 'package:flutter/material.dart';

InputImage convertFromJpeg(Uint8List jpegData, double w, double h) { return InputImage.fromBytes( bytes: DartImageHelper.convertJpegToYUV(jpegData), metadata: InputImageMetadata( bytesPerRow: -1, format: InputImageFormat.yuv_420_888, rotation: InputImageRotation.rotation0deg, size: Size(w, h), ) ); }

Uint8List convertJpegToYUV(Uint8List jpegData) { // Decode JPEG data into an image object AndroidImage.Image image = AndroidImage.decodeImage(jpegData)!;

// Convert the image to YUV420sp format
AndroidImage.Image convertedImage = AndroidImage.copyResize(image, width: image.width, height: image.height);
Uint8List yuvData = concatenatePlanes(convertedImage);

return yuvData;

}

Uint8List concatenatePlanes(AndroidImage.Image image) { final int uvRowStride = (image.width / 2).ceil() * 2; final int uvPixelStride = 2;

final int ySize = image.width * image.height;
final int uvSize = uvRowStride * image.height ~/ 2;

final Uint8List result = Uint8List(ySize + uvSize);

// Copy Y plane (full resolution)
for (int y = 0; y < image.height; y++) {
  final int yOffset = y * image.width;
  //final Uint8List row = image.getBytes( format: AndroidImage.Format.luminance, y: y);
  final Uint8List row = image.getBytes();
  result.setRange(yOffset, yOffset + image.width, row);
}

// Copy UV plane (half resolution)
final int uvOffset = ySize;
for (int y = 0; y < image.height; y += 2) {
  for (int x = 0; x < image.width; x += 2) {
    final int uOffset = uvOffset + (y * uvRowStride ~/ 2) + (x * uvPixelStride);
    final int vOffset = uOffset + 1;

    //final Uint8List uvRow = image.getBytes(format: img.Format.cbCr, x: x, y: y);
    final Uint8List uvRow = image.getBytes();
    result[uOffset] = uvRow[0];
    result[vOffset] = uvRow[1];
  }
}

return result;

} `

[badpaybad]

I tested this worked well in android ` import 'package:image/image.dart' as DartImage; InputImage convertFromJpeg(Uint8List jpegData, double w, double h) { return InputImage.fromBytes( bytes: convertImageToYUV420SP(DartImage.decodeJpg(jpegData)!), metadata: InputImageMetadata( bytesPerRow: -1, format: InputImageFormat.nv21, rotation: InputImageRotation.rotation0deg, size: Size(w, h), )); }

Uint8List convertImageToYUV420SP(DartImage.Image image) { int width = image.width; int height = image.height; final int frameSize = width height; Uint8List yuv420sp = Uint8List(frameSize 3 ~/ 2); for (int j = 0, yp = 0; j < height; j++) { for (int i = 0; i < width; i++, yp++) { var p = image.getPixel(i, j); int r = p.r.toInt(); int g = p.g.toInt(); int b = p.b.toInt(); yuv420sp[yp] = ((66 r + 129 g + 25 b + 128) >> 8) + 16; if (j % 2 == 0 && i % 2 == 0) { int uvp = frameSize + (j >> 1) width + i; yuv420sp[uvp] = ((-38 r - 74 g + 112 b + 128) >> 8) + 128; yuv420sp[uvp + 1] = ((112 r - 94 g - 18 b + 128) >> 8) + 128; } } } return yuv420sp; }

`