Enum PngFilterMode

Namespace: Egami.Formats.Png

Assembly: Egami.dll

How the PNG writer filters scanlines before compression (PNG specification, section 12.7).

public enum PngFilterMode

Fields

Adaptive = 0: For each row, try all five filters and keep the one with the smallest sum of absolute values, as the specification recommends. Palette images and bit depths below 8 use no filter.
Average = 4: Difference from the average of left and above.
None = 1: No filter.
Paeth = 5: Difference from the Paeth predictor of left, above and upper-left.
Sub = 2: Difference from the pixel to the left.
Up = 3: Difference from the pixel above.

Examples

// Force a palette, choose a filter and a zlib strategy, and keep a private chunk.
((PngDetails)image.Metadata.FormatDetails!).OtherChunks.Add(
    new PngChunk("prVt", "hello"u8.ToArray(), PngChunkPosition.AfterImageData));
image.Save("duck-palette.png", new PngWriterOptions
{
    ColorType = PngColorType.Palette,
    Filter = PngFilterMode.Paeth,
    CompressionStrategy = PngCompressionStrategy.Filtered,
});

Table of Contents

Enum PngFilterMode

Fields

Examples