bmp-class

 private static Bitmap GetArgbCopy(Image sourceImage)
        {
            Bitmap bmpNew = new Bitmap(sourceImage.Width, sourceImage.Height, PixelFormat.Format32bppArgb);


            using (Graphics graphics = Graphics.FromImage(bmpNew))
            {
                graphics.DrawImage(sourceImage, new Rectangle(0, 0, bmpNew.Width, bmpNew.Height), new Rectangle(0, 0, bmpNew.Width, bmpNew.Height), GraphicsUnit.Pixel);
                graphics.Flush();
            }


            return bmpNew;
        }

        public static Bitmap CopyWithTransparency(this Image sourceImage, byte alphaComponent = 100)
        {
            Bitmap bmpNew = GetArgbCopy(sourceImage);
            BitmapData bmpData = bmpNew.LockBits(new Rectangle(0, 0, sourceImage.Width, sourceImage.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);


            IntPtr ptr = bmpData.Scan0;


            byte[] byteBuffer = new byte[bmpData.Stride * bmpNew.Height];


            Marshal.Copy(ptr, byteBuffer, 0, byteBuffer.Length);


            for (int k = 3; k < byteBuffer.Length; k += 4)
            {
                byteBuffer[k] = alphaComponent;
            }


            Marshal.Copy(byteBuffer, 0, ptr, byteBuffer.Length);


            bmpNew.UnlockBits(bmpData);


            bmpData = null;
            byteBuffer = null;


            return bmpNew;
        }

        public static Bitmap CopyAsGrayscale(this Image sourceImage)
        {
            Bitmap bmpNew = GetArgbCopy(sourceImage);
            BitmapData bmpData = bmpNew.LockBits(new Rectangle(0, 0, sourceImage.Width, sourceImage.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);


            IntPtr ptr = bmpData.Scan0;


            byte[] byteBuffer = new byte[bmpData.Stride * bmpNew.Height];


            Marshal.Copy(ptr, byteBuffer, 0, byteBuffer.Length);


            float rgb = 0;


            for (int k = 0; k < byteBuffer.Length; k += 4)
            {
                rgb = byteBuffer[k] * 0.11f;
                rgb += byteBuffer[k + 1] * 0.59f;
                rgb += byteBuffer[k + 2] * 0.3f;


                byteBuffer[k] = (byte)rgb;
                byteBuffer[k + 1] = byteBuffer[k];
                byteBuffer[k + 2] = byteBuffer[k];


                byteBuffer[k + 3] = 255;
            }


            Marshal.Copy(byteBuffer, 0, ptr, byteBuffer.Length);


            bmpNew.UnlockBits(bmpData);


            bmpData = null;
            byteBuffer = null;


            return bmpNew;
        }

        public static Bitmap CopyAsSepiaTone(this Image sourceImage)
        {
            Bitmap bmpNew = GetArgbCopy(sourceImage);
            BitmapData bmpData = bmpNew.LockBits(new Rectangle(0, 0, sourceImage.Width, sourceImage.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);


            IntPtr ptr = bmpData.Scan0;


            byte[] byteBuffer = new byte[bmpData.Stride * bmpNew.Height];


            Marshal.Copy(ptr, byteBuffer, 0, byteBuffer.Length);


            byte maxValue = 255;
            float r = 0;
            float g = 0;
            float b = 0;


            for (int k = 0; k < byteBuffer.Length; k += 4)
            {
                r = byteBuffer[k] * 0.189f + byteBuffer[k + 1] * 0.769f + byteBuffer[k + 2] * 0.393f;
                g = byteBuffer[k] * 0.168f + byteBuffer[k + 1] * 0.686f + byteBuffer[k + 2] * 0.349f;
                b = byteBuffer[k] * 0.131f + byteBuffer[k + 1] * 0.534f + byteBuffer[k + 2] * 0.272f;


                byteBuffer[k + 2] = (r > maxValue ? maxValue : (byte)r);
                byteBuffer[k + 1] = (g > maxValue ? maxValue : (byte)g);
                byteBuffer[k] = (b > maxValue ? maxValue : (byte)b);
            }


            Marshal.Copy(byteBuffer, 0, ptr, byteBuffer.Length);


            bmpNew.UnlockBits(bmpData);


            bmpData = null;
            byteBuffer = null;


            return bmpNew;
        }

        public static Bitmap CopyAsNegative(this Image sourceImage)
        {
            Bitmap bmpNew = GetArgbCopy(sourceImage);
            BitmapData bmpData = bmpNew.LockBits(new Rectangle(0, 0, sourceImage.Width, sourceImage.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);


            IntPtr ptr = bmpData.Scan0;


            byte[] byteBuffer = new byte[bmpData.Stride * bmpNew.Height];


            Marshal.Copy(ptr, byteBuffer, 0, byteBuffer.Length);
            byte[] pixelBuffer = null;


            int pixel = 0;


            for (int k = 0; k < byteBuffer.Length; k += 4)
            {
                pixel = ~BitConverter.ToInt32(byteBuffer, k);
                pixelBuffer = BitConverter.GetBytes(pixel);


                byteBuffer[k] = pixelBuffer[0];
                byteBuffer[k + 1] = pixelBuffer[1];
                byteBuffer[k + 2] = pixelBuffer[2];
            }


            Marshal.Copy(byteBuffer, 0, ptr, byteBuffer.Length);


            bmpNew.UnlockBits(bmpData);


            bmpData = null;
            byteBuffer = null;


            return bmpNew;
        }