Class EncodedImage

Namespace

Egami.Drawing

Assembly

Egami.Drawing.dll

An image kept as its file's bytes, such as a JPEG, for DrawImage(EncodedImage, RectF, SamplingOptions?, Paint?): a backend that can store the bytes as they are, as a PDF page stores a JPEG as DCTDecode, gets them through OnDrawEncodedImage without decoding and encoding again; every other backend draws the decoded pixels. The bytes are probed when the image is made and decoded at most once, on first need. Immutable and thread-safe.

public sealed class EncodedImage

Inheritance

object

EncodedImage

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Examples

// A JPEG kept as its bytes: a PDF backend embeds them as they are; a raster canvas draws the decoded pixels.
EncodedImage jpeg = EncodedImage.Load("photo.jpg");
canvas.DrawImage(jpeg, new RectF(20, 20, 128, 96));

Properties

Data

Gets the file's bytes.

public ReadOnlyMemory<byte> Data { get; }

Property Value

ReadOnlyMemory<byte>

Height

Gets the height of the decoded image in pixels.

public int Height { get; }

Property Value

int

Info

Gets what probing the bytes found: the format, the size, the pixel layout and the orientation.

public RasterInfo Info { get; }

Property Value

RasterInfo

Width

Gets the width of the decoded image in pixels.

public int Width { get; }

Property Value

int

Methods

Decode()

Returns the decoded image, decoding it on the first call; later calls return the same raster, which must not be changed or disposed.

public Raster Decode()

Returns

Raster

The decoded image.

Exceptions

CorruptDataException

The image data is damaged.

Load(Stream, EgamiContext?)

Reads a stream to its end into an encoded image.

public static EncodedImage Load(Stream stream, EgamiContext? context = null)

Parameters

stream Stream

The stream.

context EgamiContext

The context whose formats and limits apply, or null for the default.

Returns

EncodedImage

The image.

Examples

// A JPEG kept as its bytes: a PDF backend embeds them as they are; a raster canvas draws the decoded pixels.
EncodedImage jpeg = EncodedImage.Load("photo.jpg");
canvas.DrawImage(jpeg, new RectF(20, 20, 128, 96));

Exceptions

UnsupportedFormatException

The data is not an image Egami reads.

Load(ReadOnlyMemory<byte>, EgamiContext?)

Makes an encoded image from a file's bytes, which are kept as they are (not copied) and probed but not decoded; they must not change while the image is in use.

public static EncodedImage Load(ReadOnlyMemory<byte> data, EgamiContext? context = null)

Parameters

data ReadOnlyMemory<byte>

The file's bytes, in any format Egami reads.

context EgamiContext

The context whose formats and limits apply when probing and decoding, or null for the default.

Returns

EncodedImage

The image.

Examples

// A JPEG kept as its bytes: a PDF backend embeds them as they are; a raster canvas draws the decoded pixels.
EncodedImage jpeg = EncodedImage.Load("photo.jpg");
canvas.DrawImage(jpeg, new RectF(20, 20, 128, 96));

Exceptions

UnsupportedFormatException

The bytes are not an image Egami reads.

CorruptDataException

The header is damaged.

Load(string, EgamiContext?)

Reads a file into an encoded image.

public static EncodedImage Load(string path, EgamiContext? context = null)

Parameters

path string

The file.

context EgamiContext

The context whose formats and limits apply, or null for the default.

Returns

EncodedImage

The image.

Examples

// A JPEG kept as its bytes: a PDF backend embeds them as they are; a raster canvas draws the decoded pixels.
EncodedImage jpeg = EncodedImage.Load("photo.jpg");
canvas.DrawImage(jpeg, new RectF(20, 20, 128, 96));

Exceptions

UnsupportedFormatException

The file is not an image Egami reads.