I am using imagemagick DLL (Refer: http://www.imagemagick.org) for the resize image,
But when I re-sized animated GIF image then it going screw.
I using below code for re-size image ( image type are png, gif, jpg, bmp, tif …)
ImageMagickObject.MagickImage imgLarge = new ImageMagickObject.MagickImage();
object[] o = new object[] { strOrig, "-resize", size, "-gravity", "center", "-colorspace", "RGB", "-extent", "1024x768", strDestNw };
imgLarge.Convert(ref o);
How can I fixed it.
see the result image 
I think you have to extract every single frame from the gif first, resize every single frame and then put it back together.
Edit: like this? Not tested nor builded…