Class PngImage
Namespace: Aspose.Imaging.FileFormats.Png
Assembly: Aspose.Imaging.dll (25.2.0)
Manipulate Portable Network Graphics (PNG) raster images with our versatile API, featuring support for compression levels and various color depths including Grayscale, Indexed Color, TrueColor, and alpha channels. Seamlessly process XMP metadata, enabling comprehensive image metadata management, while easily loading PNG images, performing diverse manipulations, applying filters, and converting images to other file formats for optimal versatility and customization.
[JsonObject(MemberSerialization.OptIn)]
public class PngImage : RasterCachedImage, IDisposable, IObjectWithBounds, IRasterImageArgb32PixelLoader, IRasterImageRawDataLoader, IHasXmpData, IHasMetadataInheritance
object ← DisposableObject ← DataStreamSupporter ← Image ← RasterImage ← RasterCachedImage ← PngImage
Implements
IDisposable, IObjectWithBounds, IRasterImageArgb32PixelLoader, IRasterImageRawDataLoader, IHasXmpData, IHasMetadata
Inherited Members
RasterCachedImage.CacheData(), RasterCachedImage.Blend(Point, RasterImage, Rectangle, byte), RasterCachedImage.Resize(int, int, ResizeType), RasterCachedImage.Resize(int, int, ImageResizeSettings), RasterCachedImage.RotateFlip(RotateFlipType), RasterCachedImage.Rotate(float, bool, Color), RasterCachedImage.Crop(Rectangle), RasterCachedImage.Dither(DitheringMethod, int, IColorPalette), RasterCachedImage.Grayscale(), RasterCachedImage.BinarizeFixed(byte), RasterCachedImage.BinarizeOtsu(), RasterCachedImage.BinarizeBradley(double, int), RasterCachedImage.BinarizeBradley(double), RasterCachedImage.AdjustBrightness(int), RasterCachedImage.AdjustContrast(float), RasterCachedImage.AdjustGamma(float, float, float), RasterCachedImage.AdjustGamma(float), RasterCachedImage.OnCached(), RasterCachedImage.OnPaletteChanged(IColorPalette, IColorPalette), RasterCachedImage.IsCached, RasterImage.xmpData, RasterImage.RemoveMetadata(), RasterImage.Save(Stream, ImageOptionsBase, Rectangle), RasterImage.GetModifyDate(bool), RasterImage.Dither(DitheringMethod, int), RasterImage.Dither(DitheringMethod, int, IColorPalette), RasterImage.GetDefaultPixels(Rectangle, IPartialArgb32PixelLoader), RasterImage.GetDefaultRawData(Rectangle, IPartialRawDataLoader, RawDataSettings), RasterImage.GetDefaultArgb32Pixels(Rectangle), RasterImage.GetDefaultRawData(Rectangle, RawDataSettings), RasterImage.GetArgb32Pixel(int, int), RasterImage.GetPixel(int, int), RasterImage.SetArgb32Pixel(int, int, int), RasterImage.SetPixel(int, int, Color), RasterImage.ReadScanLine(int), RasterImage.ReadArgb32ScanLine(int), RasterImage.WriteScanLine(int, Color[]), RasterImage.WriteArgb32ScanLine(int, int[]), RasterImage.LoadPartialArgb32Pixels(Rectangle, IPartialArgb32PixelLoader), RasterImage.LoadPartialPixels(Rectangle, IPartialPixelLoader), RasterImage.LoadArgb32Pixels(Rectangle), RasterImage.LoadArgb64Pixels(Rectangle), RasterImage.LoadPartialArgb64Pixels(Rectangle, IPartialArgb64PixelLoader), RasterImage.LoadPixels(Rectangle), RasterImage.LoadCmykPixels(Rectangle), RasterImage.LoadCmyk32Pixels(Rectangle), RasterImage.LoadRawData(Rectangle, RawDataSettings, IPartialRawDataLoader), RasterImage.LoadRawData(Rectangle, Rectangle, RawDataSettings, IPartialRawDataLoader), RasterImage.SaveRawData(byte[], int, Rectangle, RawDataSettings), RasterImage.SaveArgb32Pixels(Rectangle, int[]), RasterImage.SavePixels(Rectangle, Color[]), RasterImage.SaveCmykPixels(Rectangle, CmykColor[]), RasterImage.SaveCmyk32Pixels(Rectangle, int[]), RasterImage.SetResolution(double, double), RasterImage.SetPalette(IColorPalette, bool), RasterImage.Resize(int, int, ImageResizeSettings), RasterImage.Rotate(float, bool, Color), RasterImage.Rotate(float), RasterImage.BinarizeFixed(byte), RasterImage.BinarizeOtsu(), RasterImage.BinarizeBradley(double), RasterImage.BinarizeBradley(double, int), RasterImage.Blend(Point, RasterImage, Rectangle, byte), RasterImage.Blend(Point, RasterImage, byte), RasterImage.Grayscale(), RasterImage.AdjustBrightness(int), RasterImage.AdjustContrast(float), RasterImage.AdjustGamma(float, float, float), RasterImage.AdjustGamma(float), RasterImage.GetSkewAngle(), RasterImage.NormalizeAngle(), RasterImage.NormalizeAngle(bool, Color), RasterImage.Filter(Rectangle, FilterOptionsBase), RasterImage.ReplaceColor(Color, byte, Color), RasterImage.ReplaceColor(int, byte, int), RasterImage.ReplaceNonTransparentColors(Color), RasterImage.ReplaceNonTransparentColors(int), RasterImage.ToBitmap(), RasterImage.ReleaseManagedResources(), RasterImage.UpdateMetadata(), RasterImage.UpdateDimensions(int, int), RasterImage.PremultiplyComponents, RasterImage.UseRawData, RasterImage.UpdateXmpData, RasterImage.XmpData, RasterImage.RawIndexedColorConverter, RasterImage.RawCustomColorConverter, RasterImage.RawFallbackIndex, RasterImage.RawDataSettings, RasterImage.UsePalette, RasterImage.RawDataFormat, RasterImage.RawLineSize, RasterImage.IsRawDataAvailable, RasterImage.HorizontalResolution, RasterImage.VerticalResolution, RasterImage.HasTransparentColor, RasterImage.HasAlpha, RasterImage.TransparentColor, RasterImage.ImageOpacity, RasterImage.DataLoader, Image.CanLoad(string), Image.CanLoad(string, LoadOptions), Image.CanLoad(Stream), Image.CanLoad(Stream, LoadOptions), Image.Create(ImageOptionsBase, int, int), Image.Create(Image[]), Image.Create(MultipageCreateOptions), Image.Create(string[], bool), Image.Create(string[]), Image.Create(Image[], bool), Image.GetFileFormat(string), Image.GetFileFormat(Stream), Image.GetFittingRectangle(Rectangle, int, int), Image.GetFittingRectangle(Rectangle, int[], int, int), Image.Load(string, LoadOptions), Image.Load(string), Image.Load(Stream, LoadOptions), Image.Load(Stream), Image.GetProportionalWidth(int, int, int), Image.GetProportionalHeight(int, int, int), Image.RemoveMetadata(), Image.CanSave(ImageOptionsBase), Image.Resize(int, int), Image.Resize(int, int, ResizeType), Image.Resize(int, int, ImageResizeSettings), Image.GetDefaultOptions(object[]), Image.GetOriginalOptions(), Image.ResizeWidthProportionally(int), Image.ResizeHeightProportionally(int), Image.ResizeWidthProportionally(int, ResizeType), Image.ResizeHeightProportionally(int, ResizeType), Image.ResizeWidthProportionally(int, ImageResizeSettings), Image.ResizeHeightProportionally(int, ImageResizeSettings), Image.RotateFlip(RotateFlipType), Image.Rotate(float), Image.Crop(Rectangle), Image.Crop(int, int, int, int), Image.Save(), Image.Save(string), Image.Save(string, ImageOptionsBase), Image.Save(string, ImageOptionsBase, Rectangle), Image.Save(Stream, ImageOptionsBase), Image.Save(Stream, ImageOptionsBase, Rectangle), Image.GetSerializedStream(ImageOptionsBase, Rectangle, out int), Image.SetPalette(IColorPalette, bool), Image.UpdateContainer(Image), Image.GetCanNotSaveMessage(ImageOptionsBase), Image.GetFitRectangle(Rectangle), Image.GetImage2Export(ImageOptionsBase, Rectangle, IImageExporter), Image.GetFitRectangle(Rectangle, int[]), Image.OnPaletteChanged(IColorPalette, IColorPalette), Image.OnPaletteChanging(IColorPalette, IColorPalette), Image.ReleaseManagedResources(), Image.BitsPerPixel, Image.Bounds, Image.Container, Image.Height, Image.Palette, Image.UsePalette, Image.Size, Image.Width, Image.InterruptMonitor, Image.BufferSizeHint, Image.AutoAdjustPalette, Image.HasBackgroundColor, Image.FileFormat, Image.BackgroundColor, DataStreamSupporter.timeout, DataStreamSupporter.CacheData(), DataStreamSupporter.Save(), DataStreamSupporter.Save(Stream), DataStreamSupporter.Save(string), DataStreamSupporter.Save(string, bool), DataStreamSupporter.SaveData(Stream), DataStreamSupporter.ReleaseManagedResources(), DataStreamSupporter.OnDataStreamContainerChanging(StreamContainer), DataStreamSupporter.DataStreamContainer, DataStreamSupporter.IsCached, DisposableObject.Dispose(), DisposableObject.ReleaseManagedResources(), DisposableObject.ReleaseUnmanagedResources(), DisposableObject.VerifyNotDisposed(), DisposableObject.Disposed, object.GetType(), object.MemberwiseClone(), object.ToString(), object.Equals(object?), object.Equals(object?, object?), object.ReferenceEquals(object?, object?), object.GetHashCode()
Examples
This example shows how to load a PNG image from a file.```csharp [C#]
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");
}
## Constructors
### <a id="Aspose_Imaging_FileFormats_Png_PngImage__ctor_System_Int32_System_Int32_"></a> PngImage\(int, int\)
Initialize a new object of the Aspose.Imaging.FileFormats.Png.PngImage class by providing the
width and height parameters. This constructor simplifies the creation of PNG
images by allowing developers to specify the dimensions directly, facilitating
efficient management of PNG image data within their applications.
```csharp
public PngImage(int width, int height)Parameters
width int
The width.
height int
The height.
Examples
This example shows how to create a PNG image of the specified size, fill it with a solid color and save it to a file.```csharp [C#]
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");
}
### <a id="Aspose_Imaging_FileFormats_Png_PngImage__ctor_System_String_"></a> PngImage\(string\)
Constructs a new instance of the Aspose.Imaging.FileFormats.Png.PngImage class using the path
parameter to specify the location of the image file to load. This constructor
enables developers to conveniently create PNG images by loading them from a file,
simplifying the process of working with PNG images in their applications.
```csharp
public PngImage(string path)Parameters
path string
The path to load an image.
Examples
This example shows how to load a PNG image from a file.```csharp [C#]
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");
}
### <a id="Aspose_Imaging_FileFormats_Png_PngImage__ctor_Aspose_Imaging_RasterImage_"></a> PngImage\(RasterImage\)
Creates a new instance of the Aspose.Imaging.FileFormats.Png.PngImage class by providing a raster
image as a parameter. This constructor allows developers to directly initialize a
PNG image object using an existing raster image, streamlining the process of
working with PNG images in their applications.
```csharp
public PngImage(RasterImage rasterImage)Parameters
rasterImage RasterImage
The raster image.
Examples
This example shows how to load PNG image from a BMP image.```csharp [C#]
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");
}
}
### <a id="Aspose_Imaging_FileFormats_Png_PngImage__ctor_System_String_Aspose_Imaging_FileFormats_Png_PngColorType_"></a> PngImage\(string, PngColorType\)
Initializes a new instance of the Aspose.Imaging.FileFormats.Png.PngImage class by specifying the
path to the image file and the color type. This constructor allows for convenient
creation of PNG images from files with different color types, providing
flexibility in handling various image formats.
```csharp
public PngImage(string path, PngColorType colorType)Parameters
path string
The path to load an image.
colorType PngColorType
The color type.
Examples
This example shows how to load a PNG image from a file with the specified color type.```csharp [C#]
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");
}
#### Exceptions
[ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception)
### <a id="Aspose_Imaging_FileFormats_Png_PngImage__ctor_Aspose_Imaging_RasterImage_Aspose_Imaging_FileFormats_Png_PngColorType_"></a> PngImage\(RasterImage, PngColorType\)
Creates a new instance of the Aspose.Imaging.FileFormats.Png.PngImage class by specifying a
raster image and a color type. This constructor enables developers to directly
convert raster images into PNG format while specifying the desired color type,
offering flexibility in color representation.
```csharp
public PngImage(RasterImage rasterImage, PngColorType colorType)Parameters
rasterImage RasterImage
The raster image.
colorType PngColorType
The color type.
Examples
This example shows how to load PNG image from a BMP image with the specified color type.```csharp [C#]
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");
}
}
### <a id="Aspose_Imaging_FileFormats_Png_PngImage__ctor_System_IO_Stream_"></a> PngImage\(Stream\)
Creates a new instance of the Aspose.Imaging.FileFormats.Png.PngImage class by initializing it
with a stream. This constructor allows developers to load PNG images directly
from a stream, providing flexibility in image retrieval from different sources.
```csharp
public PngImage(Stream stream)Parameters
stream Stream
The stream to load an image.
Examples
This example shows how to load a PNG image from a file or a file stream.```csharp [C#]
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");
}
}
### <a id="Aspose_Imaging_FileFormats_Png_PngImage__ctor_System_Int32_System_Int32_Aspose_Imaging_FileFormats_Png_PngColorType_"></a> PngImage\(int, int, PngColorType\)
Instantiate a fresh instance of the Aspose.Imaging.FileFormats.Png.PngImage class, specifying
the desired width, height, and color type parameters. This constructor enables
swift creation of PNG images with tailored dimensions and color configurations,
facilitating streamlined image generation for various applications and workflows.
```csharp
public PngImage(int width, int height, PngColorType colorType)Parameters
width int
The width.
height int
The height.
colorType PngColorType
The color type.
Examples
This example shows how to create a PNG image of the specified size with the specified color type, fill it with a solid color and save it to a file.```csharp [C#]
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");
}
### <a id="Aspose_Imaging_FileFormats_Png_PngImage__ctor_Aspose_Imaging_ImageOptions_PngOptions_System_Int32_System_Int32_"></a> PngImage\(PngOptions, int, int\)
Initialize a new instance of the Aspose.Imaging.FileFormats.Png.PngImage class, incorporating
PNG options alongside width and height parameters. This constructor empowers
developers to create PNG images with customizable settings and dimensions,
offering flexibility in image generation for diverse use cases.
```csharp
public PngImage(PngOptions pngOptions, int width, int height)Parameters
pngOptions PngOptions
The png options.
width int
The width.
height int
The height.
Examples
This example shows how to create a PNG image with the specified options, fill it with a linear gradient colors and save it to a file.```csharp [C#]
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");
}
## Properties
### <a id="Aspose_Imaging_FileFormats_Png_PngImage_BackgroundColor"></a> BackgroundColor
Retrieves the background color of the image, if one is specified. This property
is helpful for applications that need to identify and potentially manipulate
the background color of an image.
```csharp
public override Color BackgroundColor { get; set; }Property Value
Examples
The following example shows how to set fully transparent colors for a part of a TrueColor PNG image which doesn’t support alpha channel.```csharp [C#]
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();
}
### <a id="Aspose_Imaging_FileFormats_Png_PngImage_BitsPerPixel"></a> BitsPerPixel
Retrieve the bits per pixel value for the image. This property provides crucial
information regarding the color depth of the image, enabling developers to
understand the level of detail and color accuracy present in the image data.
```csharp
public override int BitsPerPixel { get; }Property Value
FileFormat
Retrieves the format of the file associated with the image instance. This property provides essential information regarding the file type, enabling efficient handling and processing based on the specific format requirements.
public override FileFormat FileFormat { get; }Property Value
HasAlpha
Returns a boolean value indicating whether the image has an alpha channel, which determines its transparency. This property is useful for applications that need to handle transparency, allowing developers to determine whether additional processing is required to handle transparent areas in the image.
public override bool HasAlpha { get; }Property Value
Examples
The following example shows how to check if a PNG image supports alpha-channel.```csharp [C#]
// 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
### <a id="Aspose_Imaging_FileFormats_Png_PngImage_HasBackgroundColor"></a> HasBackgroundColor
Retrieves a boolean value indicating whether the image has a background color.
This property is useful for applications needing to determine if an image
includes a background color, which can be important for various processing
tasks such as compositing, rendering, or exporting.
```csharp
public override bool HasBackgroundColor { get; set; }Property Value
Examples
The following example shows how to set fully transparent colors for a part of a TrueColor PNG image which doesn’t support alpha channel.```csharp [C#]
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();
}
### <a id="Aspose_Imaging_FileFormats_Png_PngImage_HasTransparentColor"></a> HasTransparentColor
Provides a boolean value indicating whether the image contains a transparent
color. This property is crucial for applications that need to handle
transparency, allowing developers to determine whether additional processing is
required to handle transparent regions in the image.
```csharp
public override bool HasTransparentColor { get; set; }Property Value
Examples
The following example shows how to set fully transparent colors for a part of a TrueColor PNG image which doesn’t support alpha channel.```csharp [C#]
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();
}
### <a id="Aspose_Imaging_FileFormats_Png_PngImage_Height"></a> Height
Obtain the height of the image. This property returns the vertical dimension of
the image, allowing developers to determine its size in pixels along the
vertical axis.
```csharp
public override int Height { get; }Property Value
HorizontalResolution
Retrieve or modify the horizontal resolution of the image. This property represents the number of pixels per inch along the horizontal axis of the image. Adjusting this resolution can affect the physical size of the image when printed or displayed.
public override double HorizontalResolution { get; set; }Property Value
Examples
The following example shows how to set horizontal/vertical resolution of a PNG image.```csharp [C#]
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);
}
}
### <a id="Aspose_Imaging_FileFormats_Png_PngImage_Interlaced"></a> Interlaced
Retrieves a boolean value indicating whether the Aspose.Imaging.FileFormats.Png.PngImage is
interlaced, which determines if the image data is stored in a progressive
manner for faster loading or transmission.
```csharp
public bool Interlaced { get; }Property Value
IsInterlaced
Returns a boolean value indicating if the image instance is interlaced. This property is crucial for optimizing loading strategies and ensuring efficient performance during image processing or display tasks.
public bool IsInterlaced { get; }Property Value
RawDataFormat
Accesses the raw data format of the image. This property provides insight into how the image data is structured internally, which can be useful for advanced image processing tasks or format conversion.
public override PixelDataFormat RawDataFormat { get; }Property Value
Examples
The following example loads PNG images and prints information about raw data format and alpha channel.```csharp [C#]
// 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
### <a id="Aspose_Imaging_FileFormats_Png_PngImage_TransparentColor"></a> TransparentColor
Retrieves the transparent color of the image, if it exists. This property is
valuable for applications requiring precise handling of transparent areas
within images, allowing developers to access and manipulate the specific
transparent color used.
```csharp
public override Color TransparentColor { get; set; }Property Value
Examples
The following example shows how to set fully transparent colors for a part of a TrueColor PNG image which doesn’t support alpha channel.```csharp [C#]
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();
}
### <a id="Aspose_Imaging_FileFormats_Png_PngImage_VerticalResolution"></a> VerticalResolution
Provides access to the vertical resolution of the image. Developers can use
this property to retrieve or modify the resolution setting, which indicates the
number of pixels per inch (PPI) along the vertical axis of the image.
```csharp
public override double VerticalResolution { get; set; }Property Value
Examples
The following example shows how to set horizontal/vertical resolution of a PNG image.```csharp [C#]
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);
}
}
### <a id="Aspose_Imaging_FileFormats_Png_PngImage_Width"></a> Width
Allows retrieval of the width of the image, providing essential information
about its dimensions. This property is frequently used by developers to
determine the image's width, enabling them to perform various operations based
on its size
```csharp
public override int Width { get; }Property Value
XmpData
Accesses or modifies the Extensible Metadata Platform (XMP) metadata associated with the image. This property facilitates the extraction, modification, or addition of metadata, enabling comprehensive management of image-related information.
public override XmpPacketWrapper XmpData { get; set; }Property Value
Methods
GetDefaultOptions(object[])
Gets the default options.
public override ImageOptionsBase GetDefaultOptions(object[] args)Parameters
args object[]
The arguments.
Returns
Default options
GetModifyDate(bool)
Retrieves the timestamp indicating the most recent modification of the resource image. This method provides access to vital metadata, enabling applications to ascertain when the image was last altered, facilitating version tracking and content management.
public override DateTime GetModifyDate(bool useDefault)Parameters
useDefault bool
if set to true uses the information from FileInfo as default value.
Returns
The date and time the resource image was last modified.
GetOriginalOptions()
Gets the options based on the original file settings. This can be helpful to keep bit-depth and other parameters of the original image unchanged. For example, if we load a black-white PNG image with 1 bit per pixel and then save it using the Aspose.Imaging.DataStreamSupporter.Save(System.String) method, the output PNG image with 8-bit per pixel will be produced. To avoid it and save PNG image with 1-bit per pixel, use this method to get corresponding saving options and pass them to the Aspose.Imaging.Image.Save(System.String,Aspose.Imaging.ImageOptionsBase) method as the second parameter.
public override ImageOptionsBase GetOriginalOptions()Returns
The options based on the original file settings.
OnPaletteChanged(IColorPalette, IColorPalette)
Called when palette is changed.
protected override void OnPaletteChanged(IColorPalette oldPalette, IColorPalette newPalette)Parameters
oldPalette IColorPalette
The old palette.
newPalette IColorPalette
The new palette.
SaveData(Stream)
The save data.
protected override void SaveData(Stream stream)Parameters
stream Stream
The stream.
UpdateDimensions(int, int)
The update dimensions.
protected override void UpdateDimensions(int newWidth, int newHeight)Parameters
newWidth int
The new width.
newHeight int
The new height.
UpdateMetadata()
Updates the image last modification date and time.
protected override void UpdateMetadata()