AForge.Imaging.Filters.HSLLinear.ProcessFilter C# (CSharp) Method

        protected override unsafe void ProcessFilter( UnmanagedImage image, Rectangle rect )
        {
            int pixelSize = Image.GetPixelFormatSize( image.PixelFormat ) / 8;

            int startX  = rect.Left;
            int startY  = rect.Top;
            int stopX   = startX + rect.Width;
            int stopY   = startY + rect.Height;
            int offset  = image.Stride - rect.Width * pixelSize;

            RGB rgb = new RGB( );
            HSL hsl = new HSL( );

            float kl = 0, bl = 0;
            float ks = 0, bs = 0;

            // luminance line parameters
            if ( inLuminance.Max != inLuminance.Min )
            {
                kl = ( outLuminance.Max - outLuminance.Min ) / ( inLuminance.Max - inLuminance.Min );
                bl = outLuminance.Min - kl * inLuminance.Min;
            }
            // saturation line parameters
            if ( inSaturation.Max != inSaturation.Min )
            {
                ks = ( outSaturation.Max - outSaturation.Min ) / ( inSaturation.Max - inSaturation.Min );
                bs = outSaturation.Min - ks * inSaturation.Min;
            }

            // do the job
            byte* ptr = (byte*) image.ImageData.ToPointer( );

            // allign pointer to the first pixel to process
            ptr += ( startY * image.Stride + startX * pixelSize );

            // for each row
            for ( int y = startY; y < stopY; y++ )
            {
                // for each pixel
                for ( int x = startX; x < stopX; x++, ptr += pixelSize )
                {
                    rgb.Red   = ptr[RGB.R];
                    rgb.Green = ptr[RGB.G];
                    rgb.Blue  = ptr[RGB.B];

                    // convert to HSL
                    AForge.Imaging.HSL.FromRGB( rgb, hsl );

                    // do luminance correction
                    if ( hsl.Luminance >= inLuminance.Max )
                        hsl.Luminance = outLuminance.Max;
                    else if ( hsl.Luminance <= inLuminance.Min )
                        hsl.Luminance = outLuminance.Min;
                    else
                        hsl.Luminance = kl * hsl.Luminance + bl;

                    // do saturation correct correction
                    if ( hsl.Saturation >= inSaturation.Max )
                        hsl.Saturation = outSaturation.Max;
                    else if ( hsl.Saturation <= inSaturation.Min )
                        hsl.Saturation = outSaturation.Min;
                    else
                        hsl.Saturation = ks * hsl.Saturation + bs;

                    // convert back to RGB
                    AForge.Imaging.HSL.ToRGB( hsl, rgb );

                    ptr[RGB.R] = rgb.Red;
                    ptr[RGB.G] = rgb.Green;
                    ptr[RGB.B] = rgb.Blue;
                }
                ptr += offset;
            }
        }
    }