PngQualityFactor Property

public int PngQualityFactor {get; set;}

public void TestPngImageOptimizer( )
   {
      // Initialize the RasterCodecs class
      RasterCodecs codecs = new RasterCodecs();

      // The input and output location
      string inputFileName = Path.Combine(LEAD_VARS.ImagesDir, "LittleGFlyingAlpha.png");
      string outputFolder = Path.Combine(LEAD_VARS.ImagesDir, "OptimizedImages");

      // Initialize a new Optimizer object
      ImageOptimizer optimizer = new ImageOptimizer();

      // Optimization Options
      ImageOptimizerOptions options = ImageOptimizerOptions.Default;

      // Set custom optimization options
      options.Distance = 20;
      options.Percent = 15;
      options.PngQualityFactor = 4;

      IntPtr bufferPtr;
      int bufferSize = 0;
      LoadFileIntoPointer(inputFileName, out bufferPtr, out bufferSize);

      if(IntPtr.Zero != bufferPtr && bufferSize > 0)
      {
         RasterNativeBuffer optBuffer = optimizer.OptimizeBuffer(codecs, bufferPtr, bufferSize, options, null);

         // Free orgBuffer.PointerBuffer, since it won't be needed anymore.
         Marshal.FreeHGlobal(bufferPtr);

         // Save this image into the output folder
         // Make sure the output folder exists
         if(!Directory.Exists(outputFolder))
            Directory.CreateDirectory(outputFolder);

         // Get the name of the output file from the input file
         string outputFileName = Path.Combine(outputFolder, Path.GetFileName(inputFileName));

         // Save the optimized buffer to the output file
         using(FileStream fs = File.Create(outputFileName))
         {
            byte[] optArray = new byte[optBuffer.Length];

            Marshal.Copy(optBuffer.Data, optArray, 0, optArray.Length);
            fs.Write(optArray, 0, optArray.Length);
         }

         // Free optBuffer.PointerBuffer, since it won't be needed anymore.
         Marshal.FreeHGlobal(optBuffer.Data);

         // Compare the original image size with the optimized size.
         long orgSize = new FileInfo(inputFileName).Length;
         long optSize = new FileInfo(outputFileName).Length;
         int percentage = (int)((double)optSize * 100.0 / orgSize);

         string message = string.Format(
            "Original image size: {0} KB{1}Optimized image size: {2} KB{1}Percentage: {3}%",
            orgSize / 1024, Environment.NewLine, optSize / 1024,
            100 - percentage);
         MessageBox.Show(message);
      }

      //shutdown the RasterCodecs class.
   }

   // This method opens an image file and loads it into IntPtr.
   private void LoadFileIntoPointer(string fileName, out IntPtr ptr, out int size)
   {
      using(FileStream fs = File.OpenRead(fileName))
      {
         // Allocate memory to load the file
         size = (int)fs.Length;
         ptr = Marshal.AllocHGlobal(size);

         // Load in 32K chunks
         const int bufferSize = 32 * 1024;
         byte[] buffer = new byte[bufferSize];

         int bytesToRead;
         int bytesLeft = (int)fs.Length;
         IntPtr tempPtr = ptr;   // where we are
         do
         {
            // read a chunk
            bytesToRead = Math.Min(bufferSize, bytesLeft);
            if(bytesToRead > 0)
            {
               fs.Read(buffer, 0, bytesToRead);

               // copy into our buffer
               Marshal.Copy(buffer, 0, tempPtr, bytesToRead);

               // move the temp pointer
               tempPtr = new IntPtr(tempPtr.ToInt64() + bytesToRead);

               bytesLeft -= bytesToRead;
            }
         }
         while(bytesToRead > 0);
      }
   }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}