I need to rotate an image

Question

I need to rotate an image that is passed to a function as an array of BitmapFrames. the finished product needs to be saved as a BitmapFrame as well so I can send it to my Export-Image function. Help?

[Cmdlet(VerbsData.ConvertTo, "Rotate")]
public class RotateCmdlet : PSCmdlet
{
    private BitmapFrame[] bFrame, outFrame;
    private BitmapSource src;
    private double pixelsize;
    private int degrees;
    private byte[] pixels, outPixels;

    [Parameter(ValueFromPipeline = true,
        ValueFromPipelineByPropertyName = true), ValidateNotNullOrEmpty]
    public BitmapFrame[] Bitmap
    {
        get
        {
            return bFrame;
        }
        set
        {
            bFrame = value;
        }
    }

    [Parameter(Position = 0), ValidateNotNullOrEmpty]
    public int Degrees
    {
        get
        {
            return degrees;
        }
        set
        {
            degrees = value;
        }
    }

    protected override void ProcessRecord()
    {
        base.ProcessRecord();
        Console.Write("Rotating the image {0} degrees...\n\n", degrees);
        outFrame = new BitmapFrame[bFrame.Length];
        for (int c = 0; c < bFrame.Length; c++)
        {
            Image image;

            pixelsize = bFrame[c].PixelWidth * bFrame[c].PixelHeight;
            pixels = new byte[(int)pixelsize];
            outPixels = new byte[(int)pixelsize];
            bFrame[c].CopyPixels(pixels, (int)(bFrame[c].Width * (bFrame[c].Format.BitsPerPixel / 8.0)), 0);

            Stream strm = new MemoryStream(pixels);
            image = Image.FromStream(strm);

            var newBitmap = new Bitmap((int)bFrame[c].PixelWidth, (int)bFrame[c].PixelHeight);
            var graphics = Graphics.FromImage(newBitmap);
            graphics.TranslateTransform((float)bFrame[c].PixelWidth / 2, (float)bFrame[c].PixelHeight / 2);
            graphics.RotateTransform(degrees);
            graphics.TranslateTransform(-(float)bFrame[c].PixelWidth / 2, -(float)bFrame[c].PixelHeight / 2);
            graphics.DrawImage(image, new System.Drawing.Point(0, 0));

            for (int i = 0; i < pixelsize; i++)
            {
                outPixels[i] = pixels[i];
            }

            src = BitmapSource.Create(bFrame[c].PixelWidth, bFrame[c].PixelHeight, bFrame[c].DpiX, bFrame[c].DpiY,
                bFrame[c].Format, bFrame[c].Palette, outPixels, (int)(bFrame[c].Width * (bFrame[c].Format.BitsPerPixel / 8)));
            outFrame[c] = BitmapFrame.Create(src);
        }
        WriteObject(outFrame);
    }
}

Answer 1

It seems that the error you're getting on the FromStream call might be because the image format is invalid. This could be for many reasons and since I'm not sure exactly how this Cmdlet is being used I will make an assumption:

I may be incorrect here, but since you're passing in an array of BitMapFrame's, I'm wondering if the ProcessRecord is being called once for each array element. The only way to truly tell is to see how you're Cmdlet is being invoked. For example, if your BitMap parameter is coming from the pipeline then there is a good chance that ProcessRecord is being called once for each BitMapFrame in the array.

Does that make sense?