Class PngImage

[JsonObject(MemberSerialization.OptIn)]
public class PngImage : RasterCachedImage, IDisposable, IObjectWithBounds, IRasterImageArgb32PixelLoader, IRasterImageRawDataLoader, IHasXmpData, IHasMetadata

string dir = "c:\\temp\\";

                                                                  // Load a PNG image from a file.
                                                                  using (Aspose.Imaging.FileFormats.Png.PngImage pngImage = new Aspose.Imaging.FileFormats.Png.PngImage(dir + "sample.png"))
                                                                  {
                                                                      // Transform the image to grayscale representation
                                                                      pngImage.Grayscale();

                                                                      // Save to a file.
                                                                      pngImage.Save(dir + "sample.grayscale.png");
                                                                  }

public PngImage(int width, int height)

string dir = "c:\\temp\\";

                                                                                                                                // Create a PNG image of 100x100 px.
                                                                                                                                using (Aspose.Imaging.FileFormats.Png.PngImage pngImage = new Aspose.Imaging.FileFormats.Png.PngImage(100, 100))
                                                                                                                                {
                                                                                                                                    // Do some image processing, e.g. fill the entire image in red.
                                                                                                                                    Aspose.Imaging.Graphics graphics = new Aspose.Imaging.Graphics(pngImage);
                                                                                                                                    Aspose.Imaging.Brushes.SolidBrush brush = new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.Red);
                                                                                                                                    graphics.FillRectangle(brush, pngImage.Bounds);

                                                                                                                                    // Save to a file.
                                                                                                                                    pngImage.Save(dir + "output.png");
                                                                                                                                }

public PngImage(string path)

string dir = "c:\\temp\\";

                                                                  // Load a PNG image from a file.
                                                                  using (Aspose.Imaging.FileFormats.Png.PngImage pngImage = new Aspose.Imaging.FileFormats.Png.PngImage(dir + "sample.png"))
                                                                  {
                                                                      // Transform the image to grayscale representation
                                                                      pngImage.Grayscale();

                                                                      // Save to a file.
                                                                      pngImage.Save(dir + "sample.grayscale.png");
                                                                  }

public PngImage(RasterImage rasterImage)

string dir = "c:\\temp\\";

                                                                     // Load a TrueColor PNG image from a BMP image.
                                                                     // First, create a temporal BMP image that will be a foundation for building a PNG image.
                                                                     // You can also load BMP image from a file or use an image of any other raster format.
                                                                     using (Aspose.Imaging.FileFormats.Bmp.BmpImage bmpImage = new Aspose.Imaging.FileFormats.Bmp.BmpImage(100, 100))
                                                                     {
                                                                         // Fill the entire BMP image in red.
                                                                         Aspose.Imaging.Graphics gr = new Aspose.Imaging.Graphics(bmpImage);
                                                                         Aspose.Imaging.Brushes.SolidBrush brush = new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.Red);
                                                                         gr.FillRectangle(brush, bmpImage.Bounds);

                                                                         using (Aspose.Imaging.FileFormats.Png.PngImage pngImage = new Aspose.Imaging.FileFormats.Png.PngImage(bmpImage))
                                                                         {
                                                                             System.Console.WriteLine("The PNG color type: {0}", pngImage.GetOriginalOptions());
                                                                             pngImage.Save(dir + "output.png");
                                                                         }
                                                                     }

public PngImage(string path, PngColorType colorType)

string dir = "c:\\temp\\";

                                                                                                // Load a PNG image from a file.
                                                                                                // Note that the colorful image will be converted to grayscale automatically.
                                                                                                using (Aspose.Imaging.FileFormats.Png.PngImage pngImage = new Aspose.Imaging.FileFormats.Png.PngImage(dir + "sample.png", Aspose.Imaging.FileFormats.Png.PngColorType.Grayscale))
                                                                                                {
                                                                                                    // Save to a file.
                                                                                                    pngImage.Save(dir + "sample.grayscale.png");
                                                                                                }

public PngImage(RasterImage rasterImage, PngColorType colorType)

string dir = "c:\\temp\\";

                                                                                                   // Load a grayscale PNG image from a colored BMP image.
                                                                                                   // First, create a temporal BMP image that will be a foundation for building a PNG image.
                                                                                                   // You can also load BMP image from a file or use an image of any other raster format.
                                                                                                   using (Aspose.Imaging.FileFormats.Bmp.BmpImage bmpImage = new Aspose.Imaging.FileFormats.Bmp.BmpImage(100, 100))
                                                                                                   {
                                                                                                       // Fill the entire BMP image in red.
                                                                                                       Aspose.Imaging.Graphics gr = new Aspose.Imaging.Graphics(bmpImage);
                                                                                                       Aspose.Imaging.Brushes.SolidBrush brush = new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.Red);
                                                                                                       gr.FillRectangle(brush, bmpImage.Bounds);

                                                                                                       // The colors of the image pixels will be converted to their grayscale counterparts.
                                                                                                       using (Aspose.Imaging.FileFormats.Png.PngImage pngImage = new Aspose.Imaging.FileFormats.Png.PngImage(bmpImage, Aspose.Imaging.FileFormats.Png.PngColorType.Grayscale))
                                                                                                       {
                                                                                                           pngImage.Save(dir + "output.grayscale.png");
                                                                                                       }
                                                                                                   }

public PngImage(Stream stream)

string dir = "c:\\temp\\";

                                                                                   // Load a PNG image from a file stream.
                                                                                   using (System.IO.Stream stream = System.IO.File.OpenRead(dir + "sample.png"))
                                                                                   {
                                                                                       using (Aspose.Imaging.FileFormats.Png.PngImage pngImage = new Aspose.Imaging.FileFormats.Png.PngImage(stream))
                                                                                       {
                                                                                           // Transform the image to grayscale representation
                                                                                           pngImage.Grayscale();

                                                                                           // Save to a file.
                                                                                           pngImage.Save(dir + "sample.grayscale.png");
                                                                                       }
                                                                                   }

public PngImage(int width, int height, PngColorType colorType)

string dir = "c:\\temp\\";

                                                                                                                                                              // Create a grayscale PNG image of 100x100 px.
                                                                                                                                                              // All colors will be automatically converted to the grayscale format.
                                                                                                                                                              using (Aspose.Imaging.FileFormats.Png.PngImage pngImage = new Aspose.Imaging.FileFormats.Png.PngImage(100, 100, Aspose.Imaging.FileFormats.Png.PngColorType.Grayscale))
                                                                                                                                                              {
                                                                                                                                                                  // Do some image processing, e.g. fill the entire image in red.
                                                                                                                                                                  Aspose.Imaging.Graphics graphics = new Aspose.Imaging.Graphics(pngImage);
                                                                                                                                                                  Aspose.Imaging.Brushes.SolidBrush brush = new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.Red);
                                                                                                                                                                  graphics.FillRectangle(brush, pngImage.Bounds);

                                                                                                                                                                  // Save to a file.
                                                                                                                                                                  pngImage.Save(dir + "output.grayscale.png");
                                                                                                                                                              }

public PngImage(PngOptions pngOptions, int width, int height)

string dir = "c:\\temp\\";

                                                                                                                                                Aspose.Imaging.ImageOptions.PngOptions createOptions = new Aspose.Imaging.ImageOptions.PngOptions();

                                                                                                                                                // The number of bits per color channel
                                                                                                                                                createOptions.BitDepth = 8;

                                                                                                                                                // Each pixel is a (red, green, blue) triple followed by the alpha component.
                                                                                                                                                createOptions.ColorType = Imaging.FileFormats.Png.PngColorType.TruecolorWithAlpha;

                                                                                                                                                // The maximum level of compression.
                                                                                                                                                createOptions.CompressionLevel = 9;

                                                                                                                                                // Usage of filters allows to compress continuous tonal images more effectively.
                                                                                                                                                createOptions.FilterType = Aspose.Imaging.FileFormats.Png.PngFilterType.Sub;

                                                                                                                                                // Use progressive loading
                                                                                                                                                createOptions.Progressive = true;

                                                                                                                                                // Create a PNG image with custom parameters.
                                                                                                                                                using (Aspose.Imaging.FileFormats.Png.PngImage pngImage = new Aspose.Imaging.FileFormats.Png.PngImage(createOptions, 100, 100))
                                                                                                                                                {
                                                                                                                                                    Aspose.Imaging.Brushes.LinearGradientBrush gradientBrush = new Aspose.Imaging.Brushes.LinearGradientBrush(
                                                                                                                                                            new Aspose.Imaging.Point(0, 0),
                                                                                                                                                            new Aspose.Imaging.Point(pngImage.Width, pngImage.Height),
                                                                                                                                                            Aspose.Imaging.Color.Blue,
                                                                                                                                                            Aspose.Imaging.Color.Transparent);

                                                                                                                                                    Aspose.Imaging.Graphics graphics = new Aspose.Imaging.Graphics(pngImage);

                                                                                                                                                    // Fill the image with a semi-transparent gradient.
                                                                                                                                                    graphics.FillRectangle(gradientBrush, pngImage.Bounds);

                                                                                                                                                    // Save to a file.
                                                                                                                                                    pngImage.Save(dir + "output.explicitoptions.png");
                                                                                                                                                }

public override Color BackgroundColor { get; set; }

Aspose.Imaging.ImageOptions.PngOptions createOptions = new Aspose.Imaging.ImageOptions.PngOptions();
                                                                                                                                                   createOptions.Source = new Aspose.Imaging.Sources.FileCreateSource("c:\\temp\\transparent.png", false);
                                                                                                                                                   createOptions.ColorType = Aspose.Imaging.FileFormats.Png.PngColorType.Truecolor;

                                                                                                                                                   // Create a TrueColor PNG image of 100x100 px.
                                                                                                                                                   using (Aspose.Imaging.Image image = Image.Create(createOptions, 100, 100))
                                                                                                                                                   {
                                                                                                                                                       Aspose.Imaging.FileFormats.Png.PngImage pngImage = (Aspose.Imaging.FileFormats.Png.PngImage)image;
                                                                                                                                                       Aspose.Imaging.Graphics gr = new Aspose.Imaging.Graphics(pngImage);

                                                                                                                                                       // All red pixels will be considered as fully transparent.
                                                                                                                                                       pngImage.TransparentColor = Aspose.Imaging.Color.Red;
                                                                                                                                                       pngImage.HasTransparentColor = true;

                                                                                                                                                       // All transparent pixels will have a background color.
                                                                                                                                                       pngImage.BackgroundColor = Aspose.Imaging.Color.Green;
                                                                                                                                                       pngImage.HasBackgroundColor = true;

                                                                                                                                                       // Fill the entire image with white color.
                                                                                                                                                       gr.FillRectangle(new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.White), pngImage.Bounds);

                                                                                                                                                       // Fill the top-left quarter of the image with the transparent color.
                                                                                                                                                       // This makes the top-left quarter colored in the background color.
                                                                                                                                                       Rectangle rect = new Rectangle(0, 0, pngImage.Width / 2, pngImage.Height / 2);
                                                                                                                                                       gr.FillRectangle(new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.Red), rect);

                                                                                                                                                       pngImage.Save();
                                                                                                                                                   }

public override int BitsPerPixel { get; }

public override FileFormat FileFormat { get; }

public override bool HasAlpha { get; }

// Get all supported PNG color types.
                                                                                          System.Array colorTypes = System.Enum.GetValues(typeof(Aspose.Imaging.FileFormats.Png.PngColorType));

                                                                                          foreach (Aspose.Imaging.FileFormats.Png.PngColorType colorType in colorTypes)
                                                                                          {
                                                                                              Aspose.Imaging.ImageOptions.PngOptions createOptions = new Aspose.Imaging.ImageOptions.PngOptions();
                                                                                              createOptions.Source = new Sources.StreamSource(new System.IO.MemoryStream());
                                                                                              createOptions.ColorType = colorType;

                                                                                              using (Aspose.Imaging.Image image = Image.Create(createOptions, 100, 100))
                                                                                              {
                                                                                                  Aspose.Imaging.FileFormats.Png.PngImage pngImage = (Aspose.Imaging.FileFormats.Png.PngImage)image;

                                                                                                  if (pngImage.HasAlpha)
                                                                                                  {
                                                                                                      System.Console.WriteLine("A {0} PNG image supports alpha channel", createOptions.ColorType);
                                                                                                  }
                                                                                                  else
                                                                                                  {
                                                                                                      System.Console.WriteLine("A {0} PNG image doesn't support alpha channel", createOptions.ColorType);
                                                                                                  }
                                                                                              }
                                                                                          }

                                                                                          // The output looks like this:
                                                                                          // A Grayscale PNG image doesn't support alpha channel
                                                                                          // A Truecolor PNG image doesn't support alpha channel
                                                                                          // A IndexedColor PNG image doesn't support alpha channel
                                                                                          // A GrayscaleWithAlpha PNG image supports alpha channel
                                                                                          // A TruecolorWithAlpha PNG image supports alpha channel

public override bool HasBackgroundColor { get; set; }

Aspose.Imaging.ImageOptions.PngOptions createOptions = new Aspose.Imaging.ImageOptions.PngOptions();
                                                                                                                                                   createOptions.Source = new Aspose.Imaging.Sources.FileCreateSource("c:\\temp\\transparent.png", false);
                                                                                                                                                   createOptions.ColorType = Aspose.Imaging.FileFormats.Png.PngColorType.Truecolor;

                                                                                                                                                   // Create a TrueColor PNG image of 100x100 px.
                                                                                                                                                   using (Aspose.Imaging.Image image = Image.Create(createOptions, 100, 100))
                                                                                                                                                   {
                                                                                                                                                       Aspose.Imaging.FileFormats.Png.PngImage pngImage = (Aspose.Imaging.FileFormats.Png.PngImage)image;
                                                                                                                                                       Aspose.Imaging.Graphics gr = new Aspose.Imaging.Graphics(pngImage);

                                                                                                                                                       // All red pixels will be considered as fully transparent.
                                                                                                                                                       pngImage.TransparentColor = Aspose.Imaging.Color.Red;
                                                                                                                                                       pngImage.HasTransparentColor = true;

                                                                                                                                                       // All transparent pixels will have a background color.
                                                                                                                                                       pngImage.BackgroundColor = Aspose.Imaging.Color.Green;
                                                                                                                                                       pngImage.HasBackgroundColor = true;

                                                                                                                                                       // Fill the entire image with white color.
                                                                                                                                                       gr.FillRectangle(new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.White), pngImage.Bounds);

                                                                                                                                                       // Fill the top-left quarter of the image with the transparent color.
                                                                                                                                                       // This makes the top-left quarter colored in the background color.
                                                                                                                                                       Rectangle rect = new Rectangle(0, 0, pngImage.Width / 2, pngImage.Height / 2);
                                                                                                                                                       gr.FillRectangle(new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.Red), rect);

                                                                                                                                                       pngImage.Save();
                                                                                                                                                   }

public override bool HasTransparentColor { get; set; }

Aspose.Imaging.ImageOptions.PngOptions createOptions = new Aspose.Imaging.ImageOptions.PngOptions();
                                                                                                                                                   createOptions.Source = new Aspose.Imaging.Sources.FileCreateSource("c:\\temp\\transparent.png", false);
                                                                                                                                                   createOptions.ColorType = Aspose.Imaging.FileFormats.Png.PngColorType.Truecolor;

                                                                                                                                                   // Create a TrueColor PNG image of 100x100 px.
                                                                                                                                                   using (Aspose.Imaging.Image image = Image.Create(createOptions, 100, 100))
                                                                                                                                                   {
                                                                                                                                                       Aspose.Imaging.FileFormats.Png.PngImage pngImage = (Aspose.Imaging.FileFormats.Png.PngImage)image;
                                                                                                                                                       Aspose.Imaging.Graphics gr = new Aspose.Imaging.Graphics(pngImage);

                                                                                                                                                       // All red pixels will be considered as fully transparent.
                                                                                                                                                       pngImage.TransparentColor = Aspose.Imaging.Color.Red;
                                                                                                                                                       pngImage.HasTransparentColor = true;

                                                                                                                                                       // All transparent pixels will have a background color.
                                                                                                                                                       pngImage.BackgroundColor = Aspose.Imaging.Color.Green;
                                                                                                                                                       pngImage.HasBackgroundColor = true;

                                                                                                                                                       // Fill the entire image with white color.
                                                                                                                                                       gr.FillRectangle(new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.White), pngImage.Bounds);

                                                                                                                                                       // Fill the top-left quarter of the image with the transparent color.
                                                                                                                                                       // This makes the top-left quarter colored in the background color.
                                                                                                                                                       Rectangle rect = new Rectangle(0, 0, pngImage.Width / 2, pngImage.Height / 2);
                                                                                                                                                       gr.FillRectangle(new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.Red), rect);

                                                                                                                                                       pngImage.Save();
                                                                                                                                                   }

public override int Height { get; }

public override double HorizontalResolution { get; set; }

string dir = "c:\\temp\\";

                                                                                                using (Aspose.Imaging.Image image = Aspose.Imaging.Image.Load(dir + "sample.png"))
                                                                                                {
                                                                                                    Aspose.Imaging.FileFormats.Png.PngImage pngImage = (Aspose.Imaging.FileFormats.Png.PngImage)image;

                                                                                                    // Get horizontal and vertical resolution of the PngImage.
                                                                                                    double horizontalResolution = pngImage.HorizontalResolution;
                                                                                                    double verticalResolution = pngImage.VerticalResolution;
                                                                                                    System.Console.WriteLine("The horizontal resolution, in pixels per inch: {0}", horizontalResolution);
                                                                                                    System.Console.WriteLine("The vertical resolution, in pixels per inch: {0}", verticalResolution);

                                                                                                    if (horizontalResolution != 96.0 || verticalResolution != 96.0)
                                                                                                    {
                                                                                                        // Use the SetResolution method for updating both resolution values in a single call.
                                                                                                        System.Console.WriteLine("Set resolution values to 96 dpi");
                                                                                                        pngImage.SetResolution(96.0, 96.0);

                                                                                                        System.Console.WriteLine("The horizontal resolution, in pixels per inch: {0}", pngImage.HorizontalResolution);
                                                                                                        System.Console.WriteLine("The vertical resolution, in pixels per inch: {0}", pngImage.VerticalResolution);
                                                                                                    }
                                                                                                }

public bool Interlaced { get; }

public bool IsInterlaced { get; }

public override PixelDataFormat RawDataFormat { get; }

// The PNG images to load.
                                                                                                                 string[] fileNames = new string[]
                                                                                                                 {
                                                                                                                     @"c:\temp\sample.png",
                                                                                                                     @"c:\temp\alpha.png",
                                                                                                                 };

                                                                                                                 foreach (string fileName in fileNames)
                                                                                                                 {
                                                                                                                     using (Aspose.Imaging.Image image = Aspose.Imaging.Image.Load(fileName))
                                                                                                                     {
                                                                                                                         Aspose.Imaging.FileFormats.Png.PngImage pngImage = (Aspose.Imaging.FileFormats.Png.PngImage)image;
                                                                                                                         System.Console.WriteLine("ImageFile={0}, FileFormat={1}, HasAlpha={2}", fileName, pngImage.RawDataFormat, pngImage.HasAlpha);
                                                                                                                     }
                                                                                                                 }

                                                                                                                 // The output may look like this:
                                                                                                                 // ImageFile=c:\temp\sample.png, FileFormat=Rgb24Bpp, used channels: 8,8,8, HasAlpha=False
                                                                                                                 // ImageFile=c:\temp\alpha.png, FileFormat=RGBA32Bpp, used channels: 8,8,8,8, HasAlpha=True

public override Color TransparentColor { get; set; }

Aspose.Imaging.ImageOptions.PngOptions createOptions = new Aspose.Imaging.ImageOptions.PngOptions();
                                                                                                                                                   createOptions.Source = new Aspose.Imaging.Sources.FileCreateSource("c:\\temp\\transparent.png", false);
                                                                                                                                                   createOptions.ColorType = Aspose.Imaging.FileFormats.Png.PngColorType.Truecolor;

                                                                                                                                                   // Create a TrueColor PNG image of 100x100 px.
                                                                                                                                                   using (Aspose.Imaging.Image image = Image.Create(createOptions, 100, 100))
                                                                                                                                                   {
                                                                                                                                                       Aspose.Imaging.FileFormats.Png.PngImage pngImage = (Aspose.Imaging.FileFormats.Png.PngImage)image;
                                                                                                                                                       Aspose.Imaging.Graphics gr = new Aspose.Imaging.Graphics(pngImage);

                                                                                                                                                       // All red pixels will be considered as fully transparent.
                                                                                                                                                       pngImage.TransparentColor = Aspose.Imaging.Color.Red;
                                                                                                                                                       pngImage.HasTransparentColor = true;

                                                                                                                                                       // All transparent pixels will have a background color.
                                                                                                                                                       pngImage.BackgroundColor = Aspose.Imaging.Color.Green;
                                                                                                                                                       pngImage.HasBackgroundColor = true;

                                                                                                                                                       // Fill the entire image with white color.
                                                                                                                                                       gr.FillRectangle(new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.White), pngImage.Bounds);

                                                                                                                                                       // Fill the top-left quarter of the image with the transparent color.
                                                                                                                                                       // This makes the top-left quarter colored in the background color.
                                                                                                                                                       Rectangle rect = new Rectangle(0, 0, pngImage.Width / 2, pngImage.Height / 2);
                                                                                                                                                       gr.FillRectangle(new Aspose.Imaging.Brushes.SolidBrush(Aspose.Imaging.Color.Red), rect);

                                                                                                                                                       pngImage.Save();
                                                                                                                                                   }

public override double VerticalResolution { get; set; }

string dir = "c:\\temp\\";

                                                                                                using (Aspose.Imaging.Image image = Aspose.Imaging.Image.Load(dir + "sample.png"))
                                                                                                {
                                                                                                    Aspose.Imaging.FileFormats.Png.PngImage pngImage = (Aspose.Imaging.FileFormats.Png.PngImage)image;

                                                                                                    // Get horizontal and vertical resolution of the PngImage.
                                                                                                    double horizontalResolution = pngImage.HorizontalResolution;
                                                                                                    double verticalResolution = pngImage.VerticalResolution;
                                                                                                    System.Console.WriteLine("The horizontal resolution, in pixels per inch: {0}", horizontalResolution);
                                                                                                    System.Console.WriteLine("The vertical resolution, in pixels per inch: {0}", verticalResolution);

                                                                                                    if (horizontalResolution != 96.0 || verticalResolution != 96.0)
                                                                                                    {
                                                                                                        // Use the SetResolution method for updating both resolution values in a single call.
                                                                                                        System.Console.WriteLine("Set resolution values to 96 dpi");
                                                                                                        pngImage.SetResolution(96.0, 96.0);

                                                                                                        System.Console.WriteLine("The horizontal resolution, in pixels per inch: {0}", pngImage.HorizontalResolution);
                                                                                                        System.Console.WriteLine("The vertical resolution, in pixels per inch: {0}", pngImage.VerticalResolution);
                                                                                                    }
                                                                                                }

public override int Width { get; }

public override XmpPacketWrapper XmpData { get; set; }

public override ImageOptionsBase GetDefaultOptions(object[] args)

public override DateTime GetModifyDate(bool useDefault)

public override ImageOptionsBase GetOriginalOptions()

protected override void OnPaletteChanged(IColorPalette oldPalette, IColorPalette newPalette)

protected override void SaveData(Stream stream)

protected override void UpdateDimensions(int newWidth, int newHeight)

protected override void UpdateMetadata()