public static void AbsDiff()

in Sources/Imaging/Microsoft.Psi.Imaging/ImageExtensions.cs [2254:2349]
86 lines of code
32 McCabe index (conditional complexity)

        public static void AbsDiff(this Image imageA, Image imageB, Image destImage)
        {
            if (imageA.PixelFormat != destImage.PixelFormat || imageB.PixelFormat != destImage.PixelFormat)
            {
                throw new ArgumentOutOfRangeException("destImage.PixelFormat", "destination image pixel format doesn't match source image pixel format");
            }

            if (imageA.Width != imageB.Width || imageA.Height != imageB.Height || imageA.PixelFormat != imageB.PixelFormat)
            {
                throw new ArgumentException("Images sizes/types don't match");
            }

            unsafe
            {
                int bytesPerPixel = imageA.PixelFormat.GetBytesPerPixel();
                byte* srcRowA = (byte*)imageA.ImageData.ToPointer();
                byte* srcRowB = (byte*)imageB.ImageData.ToPointer();
                byte* dstRow = (byte*)destImage.ImageData.ToPointer();
                for (int i = 0; i < imageA.Height; i++)
                {
                    byte* srcColA = srcRowA;
                    byte* srcColB = srcRowB;
                    byte* dstCol = dstRow;
                    int delta0, delta1, delta2, delta3;
                    for (int j = 0; j < imageA.Width; j++)
                    {
                        switch (imageA.PixelFormat)
                        {
                            case PixelFormat.BGRA_32bpp:
                                delta0 = srcColA[0] - srcColB[0];
                                delta1 = srcColA[1] - srcColB[1];
                                delta2 = srcColA[2] - srcColB[2];
                                delta3 = srcColA[3] - srcColB[3];
                                dstCol[0] = (byte)((delta0 < 0) ? -delta0 : delta0);
                                dstCol[1] = (byte)((delta1 < 0) ? -delta1 : delta1);
                                dstCol[2] = (byte)((delta2 < 0) ? -delta2 : delta2);
                                dstCol[3] = (byte)((delta3 < 0) ? -delta3 : delta3);
                                break;

                            case PixelFormat.BGRX_32bpp:
                                delta0 = srcColA[0] - srcColB[0];
                                delta1 = srcColA[1] - srcColB[1];
                                delta2 = srcColA[2] - srcColB[2];
                                dstCol[0] = (byte)((delta0 < 0) ? -delta0 : delta0);
                                dstCol[1] = (byte)((delta1 < 0) ? -delta1 : delta1);
                                dstCol[2] = (byte)((delta2 < 0) ? -delta2 : delta2);
                                dstCol[3] = 255;
                                break;

                            case PixelFormat.BGR_24bpp:
                            case PixelFormat.RGB_24bpp:
                                delta0 = srcColA[0] - srcColB[0];
                                delta1 = srcColA[1] - srcColB[1];
                                delta2 = srcColA[2] - srcColB[2];
                                dstCol[0] = (byte)((delta0 < 0) ? -delta0 : delta0);
                                dstCol[1] = (byte)((delta1 < 0) ? -delta1 : delta1);
                                dstCol[2] = (byte)((delta2 < 0) ? -delta2 : delta2);
                                break;

                            case PixelFormat.Gray_16bpp:
                                delta0 = ((ushort*)srcColA)[0] - ((ushort*)srcColB)[0];
                                ((ushort*)dstCol)[0] = (ushort)((delta0 < 0) ? -delta0 : delta0);
                                break;

                            case PixelFormat.Gray_8bpp:
                                delta0 = srcColA[0] - srcColB[0];
                                dstCol[0] = (byte)((delta0 < 0) ? -delta0 : delta0);
                                break;

                            case PixelFormat.RGBA_64bpp:
                                delta0 = (ushort)(((ushort*)srcColA)[0] - ((ushort*)srcColB)[0]);
                                delta1 = (ushort)(((ushort*)srcColA)[1] - ((ushort*)srcColB)[1]);
                                delta2 = (ushort)(((ushort*)srcColA)[2] - ((ushort*)srcColB)[2]);
                                delta3 = (ushort)(((ushort*)srcColA)[3] - ((ushort*)srcColB)[3]);
                                ((ushort*)dstCol)[0] = (ushort)((delta0 < 0) ? -delta0 : delta0);
                                ((ushort*)dstCol)[1] = (ushort)((delta1 < 0) ? -delta1 : delta1);
                                ((ushort*)dstCol)[2] = (ushort)((delta2 < 0) ? -delta2 : delta2);
                                ((ushort*)dstCol)[3] = (ushort)((delta3 < 0) ? -delta3 : delta3);
                                break;

                            case PixelFormat.Undefined:
                            default:
                                throw new ArgumentException(Image.ExceptionDescriptionUnexpectedPixelFormat);
                        }

                        srcColA += bytesPerPixel;
                        srcColB += bytesPerPixel;
                        dstCol += bytesPerPixel;
                    }

                    srcRowA += imageA.Stride;
                    srcRowB += imageB.Stride;
                    dstRow += destImage.Stride;
                }
            }
        }