PngColorType

Inheritance: java.lang.Object, com.aspose.ms.System.ValueType, com.aspose.ms.System.Enum

public final class PngColorType extends System.Enum

Represents the PNG image color type.

Fields

Field	Description
Grayscale	Represents the color type where each pixel is a greyscale sample.
Truecolor	Represents the color type where each pixel is an R,G,B triple.
IndexedColor	Represents the color type where each pixel is a palette index; a PLTE chunk shall appear.
GrayscaleWithAlpha	Represents the color type where each pixel is a grayscale sample followed by an alpha sample.
TruecolorWithAlpha	Represents the color type where each pixel is an R,G,B triple followed by an alpha sample.

Example: The following example shows how to compress a PNG image, using indexed color with best fit palette

// Loads png image        
String sourceFilePath = "OriginalRings.png";
String outputFilePath = "OriginalRingsOutput.png";
try (com.aspose.imaging.Image image = com.aspose.imaging.Image.load(sourceFilePath))
{
    com.aspose.imaging.imageoptions.PngOptions options = new com.aspose.imaging.imageoptions.PngOptions();
    options.setProgressive(true);
    // Use indexed color type
    options.setColorType(com.aspose.imaging.fileformats.png.PngColorType.IndexedColor);
    // Use maximal compression
    options.setCompressionLevel(9);
    // Get the closest 8-bit color palette which covers as many pixels as possible, so that a palettized image
    // is almost visually indistinguishable from a non-palletized one.
    options.setPalette(com.aspose.imaging.ColorPaletteHelper.getCloseImagePalette((com.aspose.imaging.RasterImage)image, 
                                256, Aspose.Imaging.PaletteMiningMethod.Histogram));
                     
    image.save(outputFilePath, options);
}
// The output file size should be significantly reduced

Grayscale

public static final int Grayscale

Represents the color type where each pixel is a greyscale sample.

Truecolor

public static final int Truecolor

Represents the color type where each pixel is an R,G,B triple.

IndexedColor

public static final int IndexedColor

Represents the color type where each pixel is a palette index; a PLTE chunk shall appear.

GrayscaleWithAlpha

public static final int GrayscaleWithAlpha

Represents the color type where each pixel is a grayscale sample followed by an alpha sample.

TruecolorWithAlpha

public static final int TruecolorWithAlpha

Represents the color type where each pixel is an R,G,B triple followed by an alpha sample.