com.aspose.imaging.fileformats.png

Class PngImage

java.lang.Object

com.aspose.imaging.DisposableObject

com.aspose.imaging.DataStreamSupporter

com.aspose.imaging.Image

com.aspose.imaging.RasterImage

com.aspose.imaging.RasterCachedImage

com.aspose.imaging.fileformats.png.PngImage

All Implemented Interfaces:

com.aspose.fileformats.core.interfaces.IInterlaced, IHasMetadata, IObjectWithBounds, IRasterImageArgb32PixelLoader, IRasterImageRawDataLoader, IHasXmpData, com.aspose.internal.IPixelsSaver, com.aspose.internal.progressmanagement.IProgressEventHandler, com.aspose.internal.progressmanagement.IProgressInformer, com.aspose.ms.System.IDisposable, Closeable, AutoCloseable

public class PngImage
extends RasterCachedImage
implements com.aspose.fileformats.core.interfaces.IInterlaced

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.

Code example:

This example shows how to load a PNG image from a file.

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

// Load a PNG image from a file.
com.aspose.imaging.fileformats.png.PngImage pngImage = new com.aspose.imaging.fileformats.png.PngImage(dir + "sample.png");
try {
    // Transform the image to grayscale representation
    pngImage.grayscale();

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

Constructor Summary

Constructors

Constructor and Description
PngImage(InputStream stream) Creates a new instance of the PngImage class by initializing it with a stream.
PngImage(int width, int height) Initialize a new object of the PngImage class by providing the width and height parameters.
PngImage(int width, int height, int colorType) Instantiate a fresh instance of the PngImage class, specifying the desired width, height, and color type parameters.
PngImage(PngOptions pngOptions, int width, int height) Initialize a new instance of the PngImage class, incorporating PNG options alongside width and height parameters.
PngImage(RasterImage rasterImage) Creates a new instance of the PngImage class by providing a raster image as a parameter.
PngImage(RasterImage rasterImage, int colorType) Creates a new instance of the PngImage class by specifying a raster image and a color type.
PngImage(String path) Constructs a new instance of the PngImage class using the path parameter to specify the location of the image file to load.
PngImage(String path, int colorType) Initializes a new instance of the PngImage class by specifying the path to the image file and the color type.

Method Summary

Modifier and Type	Method and Description
Color	getBackgroundColor() Retrieves the background color of the image, if one is specified.
int	getBitsPerPixel() Retrieve the bits per pixel value for the image.
ImageOptionsBase	getDefaultOptions(Object[] args) Gets the default options.
long	getFileFormat() Retrieves the format of the file associated with the image instance.
int	getHeight() Obtain the height of the image in pixels.
double	getHorizontalResolution() Retrieve or modify the horizontal resolution of the image.
boolean	getInterlaced() Retrieves a boolean value indicating whether the PngImage is interlaced, which determines if the image data is stored in a progressive manner for faster loading or transmission.
ImageOptionsBase	getOriginalOptions() Gets the options based on the original file settings.
PixelDataFormat	getRawDataFormat() Accesses the raw data format of the image.
Color	getTransparentColor() Retrieves the transparent color of the image, if it exists.
double	getVerticalResolution() Provides access to the vertical resolution of the image.
int	getWidth() Allows retrieval of the width of the image in pixels, providing essential information about its dimensions.
XmpPacketWrapper	getXmpData() Accesses or modifies the Extensible Metadata Platform (XMP) metadata associated with the image.
boolean	hasAlpha() Returns a boolean value indicating whether the image has an alpha channel, which determines its transparency.
boolean	hasBackgroundColor() Retrieves a boolean value indicating whether the image has a background color.
boolean	hasTransparentColor() Provides a boolean value indicating whether the image contains a transparent color.
boolean	isInterlaced() Gets a value indicating whether this image instance is interlaced.
void	setBackgroundColor(boolean value) Retrieves a boolean value indicating whether the image has a background color.
void	setBackgroundColor(Color value) Retrieves the background color of the image, if one is specified.
void	setHorizontalResolution(double value) Retrieve or modify the horizontal resolution of the image.
void	setTransparentColor(boolean value) Provides a boolean value indicating whether the image contains a transparent color.
void	setTransparentColor(Color value) Modifies the transparent color of the image, if it exists.
void	setVerticalResolution(double value) Provides access to the vertical resolution of the image.
void	setXmpData(XmpPacketWrapper value) Accesses or modifies the Extensible Metadata Platform (XMP) metadata associated with the image.

Methods inherited from class com.aspose.imaging.RasterCachedImage

adjustBrightness, adjustContrast, adjustGamma, adjustGamma, analyzePercentageDigitalSignature, autoBrightnessContrast, binarizeBradley, binarizeBradley, binarizeFixed, binarizeOtsu, blend, cacheData, crop, dither, embedDigitalSignature, grayscale, isCached, isDigitalSigned, normalizeHistogram, resize, resize, rotate, rotateFlip

Methods inherited from class com.aspose.imaging.RasterImage

blend, blend, blend, dither, filter, getArgb32Pixel, getDefaultArgb32Pixels, getDefaultPixels, getDefaultRawData, getDefaultRawData, getImageOpacity, getModifyDate, getPixel, getPremultiplyComponents, getRawCustomColorConverter, getRawDataSettings, getRawFallbackIndex, getRawIndexedColorConverter, getRawLineSize, getSkewAngle, getUpdateXmpData, getUseRawData, isDigitalSigned, isRawDataAvailable, isUsePalette, loadArgb32Pixels, loadArgb64Pixels, loadCmyk32Pixels, loadCmykPixels, loadPartialArgb32Pixels, loadPartialArgb64Pixels, loadPartialPixels, loadPixels, loadRawData, loadRawData, normalizeAngle, normalizeAngle, readArgb32ScanLine, readScanLine, removeMetadata, replaceColor, replaceColor, replaceNonTransparentColors, replaceNonTransparentColors, rotate, saveArgb32Pixels, saveCmyk32Pixels, saveCmykPixels, savePixels, saveRawData, setArgb32Pixel, setPalette, setPixel, setPremultiplyComponents, setRawCustomColorConverter, setRawFallbackIndex, setRawIndexedColorConverter, setResolution, setUpdateXmpData, setUseRawData, toBitmap, writeArgb32ScanLine, writeScanLine

Methods inherited from class com.aspose.imaging.Image

canLoad, canLoad, canLoad, canLoad, canSave, create, create, create, create, create, create, crop, getBounds, getBufferSizeHint, getContainer, getFileFormat, getFileFormat, getFittingRectangle, getFittingRectangle, getInterruptMonitor, getIProgressEventHandler, getPalette, getProgressEventHandlerInfo, getProportionalHeight, getProportionalWidth, getSerializedStream, getSize, isAutoAdjustPalette, load, load, load, load, load, load, resize, resizeHeightProportionally, resizeHeightProportionally, resizeHeightProportionally, resizeWidthProportionally, resizeWidthProportionally, resizeWidthProportionally, save, save, save, save, save, save, save, save, setAutoAdjustPalette, setBufferSizeHint, setInterruptMonitor, setPalette

Methods inherited from class com.aspose.imaging.DataStreamSupporter

getDataStreamContainer, save, save, save

Methods inherited from class com.aspose.imaging.DisposableObject

close, dispose, getDisposed

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PngImage

public PngImage(int width,
                int height)

Initialize a new object of the 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.

Parameters:

width - The width.

height - The height.

Code example:

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.

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

// Create a PNG image of 100x100 px.
com.aspose.imaging.fileformats.png.PngImage pngImage = new com.aspose.imaging.fileformats.png.PngImage(100, 100);
{
    // Do some image processing, e.g. fill the entire image in red.
    com.aspose.imaging.Graphics graphics = new com.aspose.imaging.Graphics(pngImage);
    com.aspose.imaging.brushes.SolidBrush brush = new com.aspose.imaging.brushes.SolidBrush(com.aspose.imaging.Color.getRed());
    graphics.fillRectangle(brush, pngImage.getBounds());

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

PngImage

public PngImage(String path)

Constructs a new instance of the 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.

Parameters:

path - The path to load an image.

Code example:

This example shows how to load a PNG image from a file.

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

// Load a PNG image from a file.
com.aspose.imaging.fileformats.png.PngImage pngImage = new com.aspose.imaging.fileformats.png.PngImage(dir + "sample.png");
try {
    // Transform the image to grayscale representation
    pngImage.grayscale();

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

PngImage

public PngImage(RasterImage rasterImage)

Creates a new instance of the 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.

Parameters:

rasterImage - The raster image.

Code example:

This example shows how to load PNG image from a BMP image.

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.
com.aspose.imaging.fileformats.bmp.BmpImage bmpImage = new com.aspose.imaging.fileformats.bmp.BmpImage(100, 100);
try {
    // Fill the entire BMP image in red.
    com.aspose.imaging.Graphics gr = new com.aspose.imaging.Graphics(bmpImage);
    com.aspose.imaging.brushes.SolidBrush brush = new com.aspose.imaging.brushes.SolidBrush(com.aspose.imaging.Color.getRed());
    gr.fillRectangle(brush, bmpImage.getBounds());

    com.aspose.imaging.fileformats.png.PngImage pngImage = new com.aspose.imaging.fileformats.png.PngImage(bmpImage);
    try {
        System.out.println("The PNG color type: " + pngImage.getOriginalOptions());
        pngImage.save(dir + "output.png");
    } finally {
        pngImage.dispose();
    }
} finally {
    bmpImage.dispose();
}

PngImage

public PngImage(String path,
                int colorType)

Initializes a new instance of the 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.

Parameters:

path - The path to load an image.

colorType - The color type.

Throws:

com.aspose.ms.System.ArgumentNullException - if path is null

Code example:

This example shows how to load a PNG image from a file with the specified color type.

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

// Load a PNG image from a file.
// Note that the colorful image will be converted to grayscale automatically.
com.aspose.imaging.fileformats.png.PngImage pngImage = new com.aspose.imaging.fileformats.png.PngImage(
        dir + "sample.png",
        com.aspose.imaging.fileformats.png.PngColorType.Grayscale);
try {
    // Save to a file.
    pngImage.save(dir + "sample.grayscale.png");
} finally {
    pngImage.dispose();
}

PngImage

public PngImage(RasterImage rasterImage,
                int colorType)

Creates a new instance of the 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.

Parameters:

rasterImage - The raster image.

colorType - The color type.

See Also:

PngColorType

Code example:

This example shows how to load PNG image from a BMP image with the specified color type.

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.
com.aspose.imaging.fileformats.bmp.BmpImage bmpImage = new com.aspose.imaging.fileformats.bmp.BmpImage(100, 100);
try {
    // Fill the entire BMP image in red.
    com.aspose.imaging.Graphics gr = new com.aspose.imaging.Graphics(bmpImage);
    com.aspose.imaging.brushes.SolidBrush brush = new com.aspose.imaging.brushes.SolidBrush(com.aspose.imaging.Color.getRed());
    gr.fillRectangle(brush, bmpImage.getBounds());

    // The colors of the image pixels will be converted to their grayscale counterparts.
    com.aspose.imaging.fileformats.png.PngImage pngImage = new com.aspose.imaging.fileformats.png.PngImage(
            bmpImage,
            com.aspose.imaging.fileformats.png.PngColorType.Grayscale);
    try {
        pngImage.save(dir + "output.grayscale.png");
    } finally {
        pngImage.dispose();
    }
} finally {
    bmpImage.dispose();
}

PngImage

public PngImage(InputStream stream)

Creates a new instance of the 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.

Parameters:

stream - The stream to load an image.

PngImage

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

Instantiate a fresh instance of the 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.

Parameters:

width - The width.

height - The height.

colorType - The color type.

See Also:

PngColorType

Code example:

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.

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

// Create a grayscale PNG image of 100x100 px.
// All colors will be automatically converted to the grayscale format.
com.aspose.imaging.fileformats.png.PngImage pngImage = new com.aspose.imaging.fileformats.png.PngImage(100, 100, com.aspose.imaging.fileformats.png.PngColorType.Grayscale);
try {
    // Do some image processing, e.g. fill the entire image in red.
    com.aspose.imaging.Graphics graphics = new com.aspose.imaging.Graphics(pngImage);
    com.aspose.imaging.brushes.SolidBrush brush = new com.aspose.imaging.brushes.SolidBrush(com.aspose.imaging.Color.getRed());
    graphics.fillRectangle(brush, pngImage.getBounds());

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

PngImage

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

Initialize a new instance of the 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.

Parameters:

pngOptions - The png options.

width - The width.

height - The height.

Code example:

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.

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

com.aspose.imaging.imageoptions.PngOptions createOptions = new com.aspose.imaging.imageoptions.PngOptions();

// The number of bits per color channel
createOptions.setBitDepth((byte) 8);

// Each pixel is a (red, green, blue) triple followed by the alpha component.
createOptions.setColorType(com.aspose.imaging.fileformats.png.PngColorType.TruecolorWithAlpha);

// The maximum level of compression.
createOptions.setCompressionLevel(9);

// Usage of filters allows to compress continuous tonal images more effectively.
createOptions.setFilterType(com.aspose.imaging.fileformats.png.PngFilterType.Sub);

// Use progressive loading
createOptions.setProgressive(true);

// Create a PNG image with custom parameters.
com.aspose.imaging.fileformats.png.PngImage pngImage = new com.aspose.imaging.fileformats.png.PngImage(createOptions, 100, 100);
try {
    com.aspose.imaging.brushes.LinearGradientBrush gradientBrush = new com.aspose.imaging.brushes.LinearGradientBrush(
            new com.aspose.imaging.Point(0, 0),
            new com.aspose.imaging.Point(pngImage.getWidth(), pngImage.getHeight()),
            com.aspose.imaging.Color.getBlue(),
            com.aspose.imaging.Color.getTransparent());

    com.aspose.imaging.Graphics graphics = new com.aspose.imaging.Graphics(pngImage);

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

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

Method Detail

getBitsPerPixel

public int getBitsPerPixel()

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.

Specified by:

getBitsPerPixel in class Image

Returns:

The image bits per pixel count.

getHeight

public int getHeight()

Obtain the height of the image in pixels. This property returns the vertical dimension of the image, allowing developers to determine its size in pixels along the vertical axis.

Specified by:

getHeight in interface IObjectWithBounds

Specified by:

getHeight in class Image

Returns:

The image height.

getHorizontalResolution

public double getHorizontalResolution()

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.

Overrides:

getHorizontalResolution in class RasterImage

Returns:

The horizontal resolution.

Note by default this value is always 96 since different platforms cannot return the screen resolution. You may consider using the SetResolution method for updating both resolution values in single call.

Code example:

The following example shows how to set horizontal/vertical resolution of a PNG image.

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

com.aspose.imaging.Image image = com.aspose.imaging.Image.load(dir + "sample.png");
try {
    com.aspose.imaging.fileformats.png.PngImage pngImage = (com.aspose.imaging.fileformats.png.PngImage) image;

    // Get horizontal and vertical resolution of the PngImage.
    double horizontalResolution = pngImage.getHorizontalResolution();
    double verticalResolution = pngImage.getVerticalResolution();
    System.out.println("The horizontal resolution, in pixels per inch: " + horizontalResolution);
    System.out.println("The vertical resolution, in pixels per inch: " + verticalResolution);

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

        System.out.println("The horizontal resolution, in pixels per inch: " + pngImage.getHorizontalResolution());
        System.out.println("The vertical resolution, in pixels per inch: " + pngImage.getVerticalResolution());
    }
} finally {
    image.dispose();
}

//The output may look like this:
//The horizontal resolution, in pixels per inch: 96.0
//The vertical resolution, in pixels per inch: 96.0

setHorizontalResolution

public void setHorizontalResolution(double value)

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.

Overrides:

setHorizontalResolution in class RasterImage

Parameters:

value - The horizontal resolution.

Note by default this value is always 96 since different platforms cannot return the screen resolution. You may consider using the SetResolution method for updating both resolution values in single call.

getFileFormat

public long getFileFormat()

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.

Overrides:

getFileFormat in class Image

See Also:

FileFormat

getRawDataFormat

public PixelDataFormat getRawDataFormat()

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.

Overrides:

getRawDataFormat in class RasterImage

Returns:

The raw data format.

See Also:

PixelDataFormat

Code example:

The following example loads PNG images and prints information about raw data format and alpha channel.

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

for (String fileName : fileNames) {
    com.aspose.imaging.Image image = com.aspose.imaging.Image.load(fileName);
    try {
        com.aspose.imaging.fileformats.png.PngImage pngImage = (com.aspose.imaging.fileformats.png.PngImage) image;
        System.out.printf("ImageFile=%s, FileFormat=%s, HasAlpha=%s", fileName, pngImage.getRawDataFormat(), pngImage.hasAlpha());
    } finally {
        image.dispose();
    }
}

// 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

getVerticalResolution

public double getVerticalResolution()

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.

Overrides:

getVerticalResolution in class RasterImage

Returns:

The vertical resolution.

Note by default this value is always 96 since different platforms cannot return the screen resolution. You may consider using the SetResolution method for updating both resolution values in single call.

Code example:

The following example shows how to set horizontal/vertical resolution of a PNG image.

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

com.aspose.imaging.Image image = com.aspose.imaging.Image.load(dir + "sample.png");
try {
    com.aspose.imaging.fileformats.png.PngImage pngImage = (com.aspose.imaging.fileformats.png.PngImage) image;

    // Get horizontal and vertical resolution of the PngImage.
    double horizontalResolution = pngImage.getHorizontalResolution();
    double verticalResolution = pngImage.getVerticalResolution();
    System.out.println("The horizontal resolution, in pixels per inch: " + horizontalResolution);
    System.out.println("The vertical resolution, in pixels per inch: " + verticalResolution);

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

        System.out.println("The horizontal resolution, in pixels per inch: " + pngImage.getHorizontalResolution());
        System.out.println("The vertical resolution, in pixels per inch: " + pngImage.getVerticalResolution());
    }
} finally {
    image.dispose();
}

//The output may look like this:
//The horizontal resolution, in pixels per inch: 96.0
//The vertical resolution, in pixels per inch: 96.0

setVerticalResolution

public void setVerticalResolution(double value)

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.

Overrides:

setVerticalResolution in class RasterImage

Parameters:

value - The vertical resolution.

Note by default this value is always 96 since different platforms cannot return the screen resolution. You may consider using the SetResolution method for updating both resolution values in single call.

getWidth

public int getWidth()

Allows retrieval of the width of the image in pixels, 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

Specified by:

getWidth in interface IObjectWithBounds

Specified by:

getWidth in class Image

Returns:

The image width.

hasTransparentColor

public boolean 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.

Overrides:

hasTransparentColor in class RasterImage

hasAlpha

public boolean 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.

Overrides:

hasAlpha in class RasterImage

Returns:

true if this instance has alpha; otherwise, false.

Code example:

The following example shows how to check if a PNG image supports alpha-channel.

// Helper class
class Utils {
    public String getPngColorTypeString(int colorType) {
        switch (colorType) {
            case com.aspose.imaging.fileformats.png.PngColorType.Grayscale:
                return "Grayscale";

            case com.aspose.imaging.fileformats.png.PngColorType.Truecolor:
                return "Truecolor";

            case com.aspose.imaging.fileformats.png.PngColorType.IndexedColor:
                return "IndexedColor";

            case com.aspose.imaging.fileformats.png.PngColorType.GrayscaleWithAlpha:
                return "GrayscaleWithAlpha";

            case com.aspose.imaging.fileformats.png.PngColorType.TruecolorWithAlpha:
                return "TruecolorWithAlpha";

            default:
                throw new IllegalArgumentException("colorType");
        }
    }
}

// Here is the main example
Utils utils = new Utils();

// Get all supported PNG color types.
java.lang.Long[] colorTypes = com.aspose.imaging.fileformats.png.PngColorType.getValues(com.aspose.imaging.fileformats.png.PngColorType.class);

for (java.lang.Long colorType : colorTypes) {
    com.aspose.imaging.imageoptions.PngOptions createOptions = new com.aspose.imaging.imageoptions.PngOptions();
    createOptions.setSource(new com.aspose.imaging.sources.StreamSource(new java.io.ByteArrayInputStream(new byte[0])));
    createOptions.setColorType(colorType.intValue());

    com.aspose.imaging.Image image = com.aspose.imaging.Image.create(createOptions, 100, 100);
    try {
        com.aspose.imaging.fileformats.png.PngImage pngImage = (com.aspose.imaging.fileformats.png.PngImage) image;

        if (pngImage.hasAlpha()) {
            System.out.printf("A %s PNG image supports alpha channel\r\n", utils.getPngColorTypeString(createOptions.getColorType()));
        } else {
            System.out.printf("A %s PNG image doesn't support alpha channel\r\n", utils.getPngColorTypeString(createOptions.getColorType()));
        }
    } finally {
        image.dispose();
    }
}

// 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

getTransparentColor

public Color getTransparentColor()

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.

Overrides:

getTransparentColor in class RasterImage

setTransparentColor

public void setTransparentColor(boolean value)

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.

Overrides:

setTransparentColor in class RasterImage

Code example:

The following example shows how to set fully transparent colors for a part of a TrueColor PNG image which doesn't support alpha channel.

com.aspose.imaging.imageoptions.PngOptions createOptions = new com.aspose.imaging.imageoptions.PngOptions();
createOptions.setSource(new com.aspose.imaging.sources.FileCreateSource("c:\\temp\\transparent.png", false));
createOptions.setColorType(com.aspose.imaging.fileformats.png.PngColorType.Truecolor);

// Create a TrueColor PNG image of 100x100 px.
com.aspose.imaging.Image image = com.aspose.imaging.Image.create(createOptions, 100, 100);
try {
    com.aspose.imaging.fileformats.png.PngImage pngImage = (com.aspose.imaging.fileformats.png.PngImage) image;
    com.aspose.imaging.Graphics gr = new com.aspose.imaging.Graphics(pngImage);

    // All red pixels will be considered as fully transparent.
    pngImage.setTransparentColor(com.aspose.imaging.Color.getRed());
    pngImage.setTransparentColor(true);

    // All transparent pixels will have a background color.
    pngImage.setBackgroundColor(com.aspose.imaging.Color.getGreen());
    pngImage.setBackgroundColor(true);

    // Fill the entire image with white color.
    gr.fillRectangle(new com.aspose.imaging.brushes.SolidBrush(com.aspose.imaging.Color.getWhite()), pngImage.getBounds());

    // Fill the top-left quarter of the image with the transparent color.
    // This makes the top-left quarter colored in the background color.
    com.aspose.imaging.Rectangle rect = new com.aspose.imaging.Rectangle(0, 0, pngImage.getWidth() / 2, pngImage.getHeight() / 2);
    gr.fillRectangle(new com.aspose.imaging.brushes.SolidBrush(com.aspose.imaging.Color.getRed()), rect);

    pngImage.save();
} finally {
    image.dispose();
}

setTransparentColor

public void setTransparentColor(Color value)

Modifies 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.

Overrides:

setTransparentColor in class RasterImage

Code example:

The following example shows how to set fully transparent colors for a part of a TrueColor PNG image which doesn't support alpha channel.

com.aspose.imaging.imageoptions.PngOptions createOptions = new com.aspose.imaging.imageoptions.PngOptions();
createOptions.setSource(new com.aspose.imaging.sources.FileCreateSource("c:\\temp\\transparent.png", false));
createOptions.setColorType(com.aspose.imaging.fileformats.png.PngColorType.Truecolor);

// Create a TrueColor PNG image of 100x100 px.
com.aspose.imaging.Image image = com.aspose.imaging.Image.create(createOptions, 100, 100);
try {
    com.aspose.imaging.fileformats.png.PngImage pngImage = (com.aspose.imaging.fileformats.png.PngImage) image;
    com.aspose.imaging.Graphics gr = new com.aspose.imaging.Graphics(pngImage);

    // All red pixels will be considered as fully transparent.
    pngImage.setTransparentColor(com.aspose.imaging.Color.getRed());
    pngImage.setTransparentColor(true);

    // All transparent pixels will have a background color.
    pngImage.setBackgroundColor(com.aspose.imaging.Color.getGreen());
    pngImage.setBackgroundColor(true);

    // Fill the entire image with white color.
    gr.fillRectangle(new com.aspose.imaging.brushes.SolidBrush(com.aspose.imaging.Color.getWhite()), pngImage.getBounds());

    // Fill the top-left quarter of the image with the transparent color.
    // This makes the top-left quarter colored in the background color.
    com.aspose.imaging.Rectangle rect = new com.aspose.imaging.Rectangle(0, 0, pngImage.getWidth() / 2, pngImage.getHeight() / 2);
    gr.fillRectangle(new com.aspose.imaging.brushes.SolidBrush(com.aspose.imaging.Color.getRed()), rect);

    pngImage.save();
} finally {
    image.dispose();
}

hasBackgroundColor

public boolean 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.

Overrides:

hasBackgroundColor in class Image

getBackgroundColor

public Color getBackgroundColor()

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.

Overrides:

getBackgroundColor in class Image

setBackgroundColor

public void setBackgroundColor(boolean value)

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.

Overrides:

setBackgroundColor in class Image

Code example:

The following example shows how to set fully transparent colors for a part of a TrueColor PNG image which doesn't support alpha channel.

com.aspose.imaging.imageoptions.PngOptions createOptions = new com.aspose.imaging.imageoptions.PngOptions();
createOptions.setSource(new com.aspose.imaging.sources.FileCreateSource("c:\\temp\\transparent.png", false));
createOptions.setColorType(com.aspose.imaging.fileformats.png.PngColorType.Truecolor);

// Create a TrueColor PNG image of 100x100 px.
com.aspose.imaging.Image image = com.aspose.imaging.Image.create(createOptions, 100, 100);
try {
    com.aspose.imaging.fileformats.png.PngImage pngImage = (com.aspose.imaging.fileformats.png.PngImage) image;
    com.aspose.imaging.Graphics gr = new com.aspose.imaging.Graphics(pngImage);

    // All red pixels will be considered as fully transparent.
    pngImage.setTransparentColor(com.aspose.imaging.Color.getRed());
    pngImage.setTransparentColor(true);

    // All transparent pixels will have a background color.
    pngImage.setBackgroundColor(com.aspose.imaging.Color.getGreen());
    pngImage.setBackgroundColor(true);

    // Fill the entire image with white color.
    gr.fillRectangle(new com.aspose.imaging.brushes.SolidBrush(com.aspose.imaging.Color.getWhite()), pngImage.getBounds());

    // Fill the top-left quarter of the image with the transparent color.
    // This makes the top-left quarter colored in the background color.
    com.aspose.imaging.Rectangle rect = new com.aspose.imaging.Rectangle(0, 0, pngImage.getWidth() / 2, pngImage.getHeight() / 2);
    gr.fillRectangle(new com.aspose.imaging.brushes.SolidBrush(com.aspose.imaging.Color.getRed()), rect);

    pngImage.save();
} finally {
    image.dispose();
}

setBackgroundColor

public void setBackgroundColor(Color value)

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.

Overrides:

setBackgroundColor in class Image

Code example:

The following example shows how to set fully transparent colors for a part of a TrueColor PNG image which doesn't support alpha channel.

com.aspose.imaging.imageoptions.PngOptions createOptions = new com.aspose.imaging.imageoptions.PngOptions();
createOptions.setSource(new com.aspose.imaging.sources.FileCreateSource("c:\\temp\\transparent.png", false));
createOptions.setColorType(com.aspose.imaging.fileformats.png.PngColorType.Truecolor);

// Create a TrueColor PNG image of 100x100 px.
com.aspose.imaging.Image image = com.aspose.imaging.Image.create(createOptions, 100, 100);
try {
    com.aspose.imaging.fileformats.png.PngImage pngImage = (com.aspose.imaging.fileformats.png.PngImage) image;
    com.aspose.imaging.Graphics gr = new com.aspose.imaging.Graphics(pngImage);

    // All red pixels will be considered as fully transparent.
    pngImage.setTransparentColor(com.aspose.imaging.Color.getRed());
    pngImage.setTransparentColor(true);

    // All transparent pixels will have a background color.
    pngImage.setBackgroundColor(com.aspose.imaging.Color.getGreen());
    pngImage.setBackgroundColor(true);

    // Fill the entire image with white color.
    gr.fillRectangle(new com.aspose.imaging.brushes.SolidBrush(com.aspose.imaging.Color.getWhite()), pngImage.getBounds());

    // Fill the top-left quarter of the image with the transparent color.
    // This makes the top-left quarter colored in the background color.
    com.aspose.imaging.Rectangle rect = new com.aspose.imaging.Rectangle(0, 0, pngImage.getWidth() / 2, pngImage.getHeight() / 2);
    gr.fillRectangle(new com.aspose.imaging.brushes.SolidBrush(com.aspose.imaging.Color.getRed()), rect);

    pngImage.save();
} finally {
    image.dispose();
}

getInterlaced

public boolean getInterlaced()

Retrieves a boolean value indicating whether the PngImage is interlaced, which determines if the image data is stored in a progressive manner for faster loading or transmission.

Returns:

true if interlaced; otherwise, false.

isInterlaced

public final boolean isInterlaced()

Gets a value indicating whether this image instance is interlaced.

Value: true if this image instance is interlaced; otherwise, false.

Specified by:

isInterlaced in interface com.aspose.fileformats.core.interfaces.IInterlaced

Returns:

a value indicating whether this image instance is interlaced.

getXmpData

public XmpPacketWrapper getXmpData()

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.

Specified by:

getXmpData in interface IHasXmpData

Overrides:

getXmpData in class RasterImage

Returns:

The XMP metadata.

setXmpData

public void setXmpData(XmpPacketWrapper value)

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.

Specified by:

setXmpData in interface IHasXmpData

Overrides:

setXmpData in class RasterImage

Parameters:

value - The XMP metadata.

getDefaultOptions

public ImageOptionsBase getDefaultOptions(Object[] args)

Gets the default options.

Overrides:

getDefaultOptions in class Image

Parameters:

args - The arguments.

Returns:

Default options

getOriginalOptions

public ImageOptionsBase 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 DataStreamSupporter.Save(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 Image.Save(string, ImageOptionsBase) method as the second parameter.

Overrides:

getOriginalOptions in class Image

Returns:

The options based on the original file settings.