How to create a Bitmap from RGB buffer data?

[pzs7602]

I want to implement a method: AnyBitmap GetBitmapFromRGBBuffer(byte[] buffer, int width, int height) The buffer is image RGB data(length=widthheight3) Thanks in advance.

[iron-production-team]

Is there a similar method, constructor or factory in System.Drawing.Bitmap which you would use to achieve this in the past? https://learn.microsoft.com/en-us/dotnet/api/system.drawing.bitmap?view=windowsdesktop-7.0

[pzs7602]

The method would be implemented in macOS/Linux/Windows, so System.Drawing.Bitmap is not the right way, that's why I choose to use AnyBitmap.

[michael-ironsoftware]

@pzs7602 Please provide the equivalent method that existed in System.Drawing.Bitmap

[pzs7602]

        // buffer size = width*height*3
        public static Avalonia.Media.Imaging.Bitmap GetBitmapFromRGBBuffer(byte[] buffer, int width, int height)
        {
            System.Drawing.Bitmap b = new System.Drawing.Bitmap(width, height, System.Drawing.Imaging.PixelFormat.Format24bppRgb);

            System.Drawing.Rectangle BoundsRect = new System.Drawing.Rectangle();
            BoundsRect.Width = width;
            BoundsRect.Height = height;

            BitmapData bmpData = b.LockBits(BoundsRect, ImageLockMode.WriteOnly, b.PixelFormat);

            IntPtr ptr = bmpData.Scan0;

            // add back dummy bytes between lines, make each line be a multiple of 4 bytes
            int skipByte = bmpData.Stride - width*3;
            byte[] newBuff = new byte[buffer.Length + skipByte*height];
            for (int j = 0; j < height; j++)
            {
                Buffer.BlockCopy(buffer, j * width * 3, newBuff, j * (width * 3 + skipByte), width * 3);
            }

            // fill in rgbValues
            Marshal.Copy(newBuff, 0, ptr, newBuff.Length);
            b.UnlockBits(bmpData);
            return ConvertToAvaloniaBitmap(b);
        }
        // conversion between System.Drawing.Bitmap and Avalonia.Media.Imaging.Bitmap
        public static Avalonia.Media.Imaging.Bitmap ConvertToAvaloniaBitmap(System.Drawing.Bitmap bitmap)
        {
            if (bitmap == null)
                return null;
            System.Drawing.Bitmap bitmapTmp = bitmap;
            var bitmapdata = bitmapTmp.LockBits(new Rectangle(0, 0, bitmapTmp.Width, bitmapTmp.Height), ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb);
            Avalonia.Media.Imaging.Bitmap bitmap1 = new Avalonia.Media.Imaging.Bitmap(Avalonia.Platform.PixelFormat.Bgra8888, Avalonia.Platform.AlphaFormat.Premul, bitmapdata.Scan0, new Avalonia.PixelSize(bitmapdata.Width, bitmapdata.Height), new Avalonia.Vector(96, 96), bitmapdata.Stride);
            bitmapTmp.UnlockBits(bitmapdata);
            bitmapTmp.Dispose();
            return bitmap1;
        }
        //  conversion between Avalonia.Media.Imaging.Bitmap and IronSoftware.Drawing.AnyBitmap
        public static Avalonia.Media.Imaging.Bitmap ConvertToAvaloniaBitmap(AnyBitmap bitmap)
        {
            if (bitmap == null)
                return null;
            var bitmapdata = bitmap.ToStream();
            bitmapdata.Position = 0;
            Avalonia.Media.Imaging.Bitmap bitmap1 = new Avalonia.Media.Imaging.Bitmap(bitmapdata);
            return bitmap1;
        }

[michael-ironsoftware]

@pzs7602 This is fixed in the latest release.