Class JxlExtraChannelImage

Namespace

Egami.Formats.Jxl

Assembly

Egami.dll

An extra channel to write with ExtraChannels: its description and its samples, as ReadExtraChannel(string, int, ReaderOptions?, EgamiContext?) gives them back.

public sealed class JxlExtraChannelImage

Inheritance

object

JxlExtraChannelImage

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Examples

// A depth map written beside the color, 16 bits, at half the size each way.
using Raster photo = Raster.Load("duck.png");
using Raster<GrayF32> depth = Raster.Create<GrayF32>((photo.Width + 1) / 2, (photo.Height + 1) / 2);
for (int y = 0; y < depth.Height; y++)
{
    for (int x = 0; x < depth.Width; x++)
    {
        depth.Row(y)[x] = new GrayF32((float)y / depth.Height);
    }
}

JxlExtraChannel description = new() { Kind = JxlExtraChannelKind.Depth, Name = "depth", BitsPerSample = 16, Subsampling = 1 };
photo.Save("with-depth.jxl", new JxlWriterOptions { Lossless = true, ExtraChannels = [new JxlExtraChannelImage(description, depth)] });

// The channels of a loaded file are not on its raster: read them, and pass them on to keep them.
using Raster loaded = Raster.Load("with-depth.jxl");
JxlDetails details = (JxlDetails)loaded.Metadata.FormatDetails!;
using Raster<GrayF32> again = JxlImage.ReadExtraChannel("with-depth.jxl", 0);

Constructors

JxlExtraChannelImage(JxlExtraChannel, Raster<GrayF32>)

Creates an extra channel to write. The caller keeps the raster and disposes it after the save.

public JxlExtraChannelImage(JxlExtraChannel channel, Raster<GrayF32> samples)

Parameters

channel JxlExtraChannel

What the channel holds and how it is stored: its kind, name, bits (1 to 24 for integers; 16 with 5 exponent bits or 32 with 8 for floats), subsampling (0 to 3), whether color is premultiplied by it (alpha only) and, for a spot color, its red, green, blue and solidity.

samples Raster<GrayF32>

The samples, at the image size halved Subsampling times each way (rounded up): 0 to 1 for integer channels, which are scaled to their bits and rounded; float channels are stored as given.

Exceptions

ArgumentNullException

channel or samples is null.

ArgumentException

The description is not one JPEG XL can store.

Properties

Channel

Gets the channel's description.

public JxlExtraChannel Channel { get; }

Property Value

JxlExtraChannel

Samples

Gets the channel's samples.

public Raster<GrayF32> Samples { get; }

Property Value

Raster<GrayF32>