PngColorType

PngColorType enumeration

Represents the PNG image color type.

public enum PngColorType

Values

Name Value Description
Grayscale 0 Represents the color type where each pixel is a greyscale sample.
Truecolor 2 Represents the color type where each pixel is an R,G,B triple.
IndexedColor 3 Represents the color type where each pixel is a palette index; a PLTE chunk shall appear.
GrayscaleWithAlpha 4 Represents the color type where each pixel is a greyscale sample followed by an alpha sample.
TruecolorWithAlpha 6 Represents the color type where each pixel is an R,G,B triple followed by an alpha sample.

Examples

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

[C#]

// Loads png image        
    string  sourceFilePath="OriginalRings.png";
    string  outputFilePath="OriginalRingsOutput.png";
    using (Aspose.Imaging.Image image = Aspose.Imaging.Image.Load(sourceFilePath))
{
    image.Save(outputFilePath, new Aspose.Imaging.ImageOptions.PngOptions()
    {
         Progressive = true,
             // Use indexed color type
         ColorType = Aspose.Imaging.FileFormats.Png.PngColorType.IndexedColor,
             // Use maximal compression
         CompressionLevel = 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.
         Palette = Aspose.Imaging.ColorPaletteHelper.GetCloseImagePalette((Aspose.Imaging.RasterImage)image, 256, Aspose.Imaging.PaletteMiningMethod.Histogram)
    });
}
    // The output file size should be significantly reduced

See Also