OpenCvSharpException: Native object address is NULL

1

We are migrate to .NET 6. After this converting image with Mat.FromStream() return exception:
Native object address is NULL . I make small project where this exception is reproduce. Hope that you can help me with this.
Here is the link for small example: https://drive.google.com/file/d/1t-BM1uxUoZ1NOsGHIhPYnCCyvLtN_er2/view?usp=sharing

2

can you please paste your code here not on some dropbox ? thank you.

3

I’m loading image from file. This code is working fine on .NET Framework 4.8 but stop working when we migrate to .NET 6

 var imagePath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, @"ImagesTest\Test.jpg");
            FileStream imageStream = new FileStream(imagePath, FileMode.Open);

            OpenCvImageWorker worker = new OpenCvImageWorker();
            var result = worker.LoadAsync(imageStream, CancellationToken.None).GetAwaiter().GetResult();

OpenCvImageWorker based on OpenCVSharp nuget:

public async Task<ImageContainer> LoadAsync(Stream imageStream, CancellationToken cancellationToken)
        {
            if (imageStream == null)
                throw new ArgumentNullException(nameof(imageStream));

            if (imageStream == Stream.Null)
                throw new InvalidOperationException("Stream is empty");

            imageStream.ToBegin();

            cancellationToken.ThrowIfCancellationRequested();
            return await Task.FromResult(new MatImageContainer(Mat.FromStream(imageStream, ImreadModes.AnyColor)));
        }


public class MatImageContainer : IDisposable
    {
        private Lazy<BitmapSource> bitmapSource;

        public MatImageContainer(Image image)
            : this((Bitmap)image)
        {
        }

        public MatImageContainer(Bitmap bitmap)
            : this(bitmap.ToMat())
        {
        }

        public MatImageContainer(Mat image)
        {
            OriginalImage = image;
            bitmapSource = new Lazy<BitmapSource>(() => OriginalImage.ToBitmapSource());
        }

        public Mat OriginalImage { get; }

        public BitmapSource Image
        {
            get => bitmapSource?.Value;
            set => throw new NotImplementedException();
        }

        public BitmapSource Thumbnail
        {
            get => throw new NotImplementedException();
            set => throw new NotImplementedException();
        }

        public void Dispose()
        {
            bitmapSource = null;

            if (!OriginalImage.IsDisposed)
                OriginalImage.Dispose();
        }
    }
4

I try but its moved into a spam

5

I’m reading photo from file into a stream. This code is working well on .NET Framework 4.8 but not working on .NET Core 3.1, .NET 5, .NET 6

 var imagePath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, @"ImagesTest\Test.jpg");
            FileStream imageStream = new FileStream(imagePath, FileMode.Open);

            OpenCvImageWorker worker = new OpenCvImageWorker();
            var result = worker.LoadAsync(imageStream, CancellationToken.None).GetAwaiter().GetResult();

OpenCvImageWorker:

 public class OpenCvImageWorker
    {
        public ImageContainer[] Load(string fileName)
        {
            if (String.IsNullOrWhiteSpace(fileName))
                throw new ArgumentNullException(nameof(fileName));

            if (!File.Exists(fileName))
                throw new FileNotFoundException("File not found", fileName);

            if (!Cv2.ImReadMulti(fileName, out Mat[] mats))
                throw new InvalidOperationException("OpenCV can't open file");

            // ReSharper disable once CoVariantArrayConversion
            return mats.Select(m => new MatImageContainer(m)).ToArray();
        }

        public async Task<ImageContainer[]> LoadAsync(string fileName)
            => await Task.FromResult(Load(fileName));

        public async Task<ImageContainer> LoadAsync(Stream imageStream, CancellationToken cancellationToken)
        {
            if (imageStream == null)
                throw new ArgumentNullException(nameof(imageStream));

            if (imageStream == Stream.Null)
                throw new InvalidOperationException("Stream is empty");

            imageStream.ToBegin();

            cancellationToken.ThrowIfCancellationRequested();
            return await Task.FromResult(new MatImageContainer(Mat.FromStream(imageStream, ImreadModes.AnyColor)));
        }
    }

public class MatImageContainer : ImageContainer
    {
        private Lazy<BitmapSource> bitmapSource;

        public MatImageContainer(Image image)
            : this((Bitmap)image)
        {
        }

        public MatImageContainer(Bitmap bitmap)
            : this(bitmap.ToMat())
        {
        }

        public MatImageContainer(Mat image)
        {
            OriginalImage = image;
            bitmapSource = new Lazy<BitmapSource>(() => OriginalImage.ToBitmapSource());
        }

        public Mat OriginalImage { get; }

        public override BitmapSource Image
        {
            get => bitmapSource?.Value;
            set => throw new NotImplementedException();
        }

        public override BitmapSource Thumbnail
        {
            get => throw new NotImplementedException();
            set => throw new NotImplementedException();
        }

        public override void Dispose()
        {
            base.Dispose();

            bitmapSource = null;

            if (!OriginalImage.IsDisposed)
                OriginalImage.Dispose();
        }
    }

 public class ImageContainer : IDisposable
    {
        public virtual BitmapSource Image { get; set; }

        public virtual BitmapSource Thumbnail { get; set; }

        public virtual void Dispose()
        {
        }
    }