Copy blob image with RW properties

[fdncred]

@cesarsouza,
I'm not sure you'll allow the PR but I have the need to manipulate Accord.Imaging.Blob properties. Specifically, I'm creating and merging my own blobs. This is an example of how I need to use it.

private Blob MergeBlobsVertically(Blob blobOne, Blob blobTwo)
{
    var newRect = new Rectangle(
        Math.Min(blobOne.Rectangle.X, blobTwo.Rectangle.X),
        Math.Min(blobOne.Rectangle.Y, blobTwo.Rectangle.Y),
        Math.Max(blobOne.Rectangle.Width, blobTwo.Rectangle.Width),
        blobOne.Rectangle.Height + blobTwo.Rectangle.Height);
    var blobBmp = new Bitmap(newRect.Width, newRect.Height);
    using (var g = Graphics.FromImage(blobBmp))
    {
        g.Clear(Color.Black);
        if (blobOne.Rectangle.Y == newRect.Y)
        {
            // Merge BlobOne on Top
            g.DrawImage(blobOne.Image.ToManagedImage(), new Point(0, 0));
            g.DrawImage(blobTwo.Image.ToManagedImage(), new Point(0, blobOne.Image.Height));
        }
        else
        {
            // Merge BlobTwo on Top
            g.DrawImage(blobTwo.Image.ToManagedImage(), new Point(0, 0));
            g.DrawImage(blobOne.Image.ToManagedImage(), new Point(0, blobTwo.Image.Height));
        }
    }
    var newBlob = new Blob(blobOne.ID, newRect, UnmanagedImage.FromManagedImage(blobBmp));
    newBlob.Area = blobOne.Area + blobTwo.Area; // Area looks to be the count of white pixels
    newBlob.CenterOfGravity = new Accord.Point(newRect.X + (newRect.Width / 2), newRect.Y + (newRect.Height / 2));
    newBlob.ColorMean = blobOne.ColorMean;
    newBlob.ColorStdDev = blobOne.ColorStdDev;
    newBlob.Fullness = (double)newBlob.Area / (newRect.Width * newRect.Height);
    // From BlobCounterBase Class
    //Blob blob = new Blob(j, new Rectangle(x1[j], y1[j], x2[j] - x1[j] + 1, y2[j] - y1[j] + 1));
    //blob.Area = blobArea;
    //blob.Fullness = (double)blobArea / ((x2[j] - x1[j] + 1) * (y2[j] - y1[j] + 1));
    //blob.CenterOfGravity = new Accord.Point((float)xc[j] / blobArea, (float)yc[j] / blobArea);
    //blob.ColorMean = Color.FromArgb((byte)(meanR[j] / blobArea), (byte)(meanG[j] / blobArea), (byte)(meanB[j] / blobArea));
    //blob.ColorStdDev = Color.FromArgb(
    //    (byte)(Math.Sqrt(stdDevR[j] / blobArea - blob.ColorMean.R * blob.ColorMean.R)),
    //    (byte)(Math.Sqrt(stdDevG[j] / blobArea - blob.ColorMean.G * blob.ColorMean.G)),
    //    (byte)(Math.Sqrt(stdDevB[j] / blobArea - blob.ColorMean.B * blob.ColorMean.B)));
    return newBlob;
}

I'm not sure I'm calculating all the properties correctly.

Thanks,
Darren

[fdncred]

Doh! Please ignore the build-all-462.cmd. I created that just to make it easier to compile.

[cesarsouza]

Hi @fdncred,

All PRs that help you achieve something you need are more than welcome. I will need some time to take a look at the PR yet, and also all the other issues that have popped up in the last week, but I will incorporate it as soon as I can.

Don't worry about the build-all462.cmd, I will remove it manually either before or after I accept the PR!

Thanks a lot for the submission,
Cesar

[cesarsouza]

I guess the main issue here is related to #627. After so many years working with Python where everything is publicly accessible, I now recognize how much more useful it would be if the project allowed more properties to be easily directly adjusted by users. As I said, I will try to accept the PR as soon as I can.

Regards,
Cesar

[fdncred]

Looks good. Thanks!